jiKik'k
fffli
JULY 1994
ISSUE # 406
USA $2.95
CANADA $3.95
A WGI Publication
Jnteniatianal Edition
All About
POSltlOIH
Wori^
> *-
•J*»
^4^.
*Aj
^am
I Feel The Comfort Of Extended
.Operations With The 1C-T2 lA! J
|(T4!A
UHFFM
TraiTsceivtf
Moximum Comfml
flfistoniff Coftstructtoi - This special
malerial pro\ides a comfortible, pOMtive
grip. The compaa design fits ihe natural
oiHT of your fingers and hand - especial^
welcome during long operating times,
BockBt Key pad - Ample spacing behveen
kej's for posiii\e, error free operaiion.
lurge Displdy - Indicates 17 different
functions, bauery capacity and
sub band frequency.
Full Crossbonci Duplex Operotioii
Dtrd Band Receivt Capcibiiity - Pennits
reception of another band (le.: 440 MHz cm
tbeIC-T21A).
Full Crossbctitd Duplex Op€ratbR - ^sible
with the unique 'Whisper mode" microphone
(standard) for telephone type QSO's.
6 Hours Operating Time"^
Low Power Consuniption - Coni^unies oidir
8 mA while standing by.
A»to Power Control - Consc^r\es the battery
by monitoring the repeater signal strength
and selecting the best matching output power
from 5 levels (down to 15 mW).
Auto low Power Function - Automatically
selects 15 mW just before banery^ cxliausiion
so you can complete your QSO.
* 55 10 6 hdur^ witlj 1 : 1:8 duty cyck (Tk high : RA : .Siimdby)
Battery Capacity Indicator -
Shows bauerj- capacit)i
New Scanning
Standards
Ultra High Speed Scan -
3 to 4 times faster than
most other handlields
(33 channels/sec, 12,5
memoiychysecO-
Bonus Bond - Can be
scanned while the
main band Is beui|;
scanned (e.g,: 70 cm
forlhelCTaiA),
For more information call our
broclriire hotlirte: (206) 450-6088
5^>^/5?^
i^Q^/y
6 Priority Watch Wodes - Check for other
signals while operating on a VTQ frequency*
Ultrs-Convenient
Repeater Operations
Suboudible Tofie Scon - Detects, displaji^
and programs the tone frequency into the
\T0. PermiLs access to a repeater when you
don't know the tone frequency
Auto Repeater Function - Automatically
activates repeater settings (duplex OX/OFF,
duplex direction, tone encoder ON/OFF)
when the operating frequeoCT falls in the
repeater output range.
Repeater Memory - QuicHj' recall setting
of your last worked repeater (RPT-M key).
5 DTWF Memories - Automatica% dial your
finrorite telephone numbers.
Selectoble DTMF Transmission Speed -
Adjust the IC-T21A/I41A to the capabilities of
the repeater (5 cps, 2,5 cps, 1 .6 cps, 1 cps).
Powerful 6 W Output Power*
Our newly designed SC-1257 power module
provides all the power necessary to reach
fringe areas. Accepts 4-16 V input,
■• Wllh Jk lis V DC power Murce,
Innovative Memory Functions
114 Memory Channels - Store all repeater
information.
Memory Select Channels - For quick
access, up to 30 can be designated Memory
Select Channels.
Memory Transfer - Quickly transfers a
memor> ckmneFs contents to VFO. Useftil for
searching for signals near a meniorv cbanncL
EEPROM - Memory information is retained
virtually forever
And More!
• IndDdes FtexltstF Antenni, Bdt Clip^ Hzndstrifi,
lecliaii?3Jtile M-€tI HaJirn Padt ^iJ Charger
• Buih'ifl Pager, Code Squelcli, Pocket Beqi It
Tone SquelcJi
KflM*fmht,llW4l|i^lJL,ldMt.<*Wai«^
jyi KBWii^w I III r inii pJffC HpJ^M^aM 1^^
!■ IMF Thi Iffi h» ii I r^Tii^ ti^w^ rf rfflll hr
ClHCLjt \ 73 aS4 HtAO^H S£.HV1C^ i^AHQ
I
INTERNATIONAL INC
FIND
Four
EQUENCIES FAST with the Stai
TRIGGER & HOLD Models, TWO Prj
tflWf^
W««--'»1^
$17:
value
-ffl *f^m
k ATH™ Series
id Below $200!!
ATH ™ SERIES FEATURES:
• Easy to use - simple controls
• Ultra fast response time
• Extra BRIGHT LED digits
• AC or Battery operation
• Maximized sensitivity
1.2 GHZ
'SOO
pre^i
i^#^
d*
HOI.O
MADE
IN
USA
"^ ^'^^c j;:r ""--
v-J>^ K <'-'jV'.iK
ATH
^ttH
^"^'^^^./.s
®'«-Ch
««7S9
i^off- -
COONT
ate**
-ATJ;,
Mfl*
i;jJ .; A.-VSN8: SSHt ^3Sj'::'
42*#:
ac.chQ
YAPTE
,N1*fN*^*"^
(T.t*!™
EFIOM*'
Optional #TA-0O Antenna
^:?5CK
e^WD MSS FILTERS
■^^^He
*tOltf
Couf^.
WARRANTY
5 Years Parts
1 Year Labor
®^^*9
'^fr.
'"^^Ut
^i^,
"w
ftOAie,
^^2-
Jtsjar
'**»*
saaooaso
H>f U1--T
nr 11^4 JlniiKJTlP
saaaaaaa
IQQD
^Jf^m
:jQao
'***,
'/A
^TH!-to
*Uto TIih*m> * M&ito
ATMrmJ
larf ft VI
■rtl««^
.'JkOTBtC^.
Factory Direct
Order Lines
SAME DAY SHIPMEI
Orders & Information
Orders On I
AX 305-561-913'!
Model 1350
Economy Frequency Counter
1-1300 MHZ, 3 gate times,
Hold switch
{No ATH or Bar Graph) ....$119,
mstrunrients are
true Pocket Size:
'^^ tta^
ACCESSORIES
#CC-90 Soft Case for all models........... $12.
#TA-90 Telescope BNC antenna............. 12.
#TA-90-L Telescope Elbow BNC antenna .,„.16.
ttRD-ISO 150 MHZ Rubber Duck antenna ..„16.
#RD-2750 27 & 50 MHZ Rubber Duck antenna.... 28.
#RD^50 450 MHZ Rubber Duck antenna ..........16.
#RD-800 Cellular phone band RD antenna 29.
#e/6A ABOVE 7 il^ms, SAVE $00 99.
#M-207-IC Interface Cable MFJ ant. analyzers,... ..10.
#P-110 200 MHZ 1X-10X probe..... 39.
#LP-22 Low Pass, Audio probe „„„.„_„„.,„25.
#DC-10 Direct, 50 OHM probe 20.
FEATURES
ATM -10
$149
ATH '15
$189
ATH-30 ATH-50
rrn
LViTira
tNTBniMMTfOiMAL. WVC.
STARTi
398 ME 3Sth St., Ft. Lauderdale, FL 33334
■^" Deep, <14 cubic in,
3nd are shipped with
factory instalfed
NhCad batteries and
AC charger/adapter.
Antennas are
optionat.
reg $f79
reg $235
reg $293
reg $333
FREQUENCY RANGE
1 MHZ -
1200 MHZ
1 MHZ-
1500 MHZ
1 MHZ-
2800 MHZ
5HZ-
2800 MHZ
AUTO TRfGGER S HOLD
YES
YES
YES
YES
SIGNAL BAR GRAPH
NO
YES
YES
YES
LOW BATTERY fNa
NO
YES
YES
YES
ONE-SHOT & RESET
NO
OPTIONAL
YES
YES
Hf-Z LOW RANGE
NO
NO
NO
YES
OPTION #HST-15 is 3
can t>e ordered with any
I high accuracy, high stability, time base
ATH series modet (0,2PPM TCXO)
upgrade that
.$100-
Extend readability distance with BAND PASS FILTERS, $49 ea.
#LP-60 DC-eOiyHZ #BP-150 130 -500 MHZ
#HP-400 400 - 1500 MHZ #HP-800 800 - 20O0 MHZ
#BP**4 All 4 Filters $189
Terms: Shipping/handling charges U.S. & Canada S% ($5 mln„ $10 max) Others add 15%, FL residents add 6% tax, COD fee $5.
VISA, MC, Discover accepted. Prices & specifications subject to change without notice or obligation.
\'*j^^.'
- l3lff&tc'Z'*y-f3N''freAOcR StRAflUc'v AnD
JRC
160-10 Meters PLUS 6 Meter Transceiver
pcwsfi
4N iJ iJA
mm '^' 'y
mtm
GQ!Gl4_ roqjfl
ta^Htt
iOiC A
'^nwf|gpfMwt:^iii
PHOfJE*
■53; ^-flTCH
•»«T^a*S THAhieCElVER
l"**~M^gp
/'^^sfloa
P^^r^
"^>1
■lS^5«-»3-
AUC^S^F^
Flit Rrr^jifr
MQHH
^aT]En
-vox-s-neu^v —
Kl**-&-flW«
M-Vft)
hiEMO
^«*" h-J-usie"
atT/«Hs
AF-$^HF
VJ /
■•^w«tin
MfMOFlv
ORlH
®-flWWC;
Fifteen
reasons why your next HF
ver should be a JST-245. . .
1
2
3
4
5
6
All-Mode Operation (SSB,CW,AM,AFSK,FM) on ell HF amateur
bands and 6 meters. JST-145, same as JST-245 but without 6
meters and built-in antenna tuner.
• JST-145 COMING SOON •
MOSFET POWER AMPLIFIER - Final PA utilizes RF MOSFETs
to achieve low distortion and high durability. Rated output Is 10
to 150 watts on all bands inciudtng 6 meters.
AUTOMATIC ANTENNA TUNER • Auto tuner included as
standard equipment. Tuner settings are automaticaily stored
in memory for fast QSY.
MULTIPLE ANTENNA SELECTION • Three antenna connec-
tions are user selectable from front panel. Antenna selection can
be stored in memory.
GENERAL COVERAGE RECEIVER* 100 kHz-30MHz, plus 48-
54 MHz receiver. Electronically tuned front-end filtering, quad-
FET mixer and quadruple conversion system {triple conversion
for FM) results in excellent dynamic range {>1 OOdB) and 3rd order
fCPof+20dBm.
IF BANDWIDTH FLEXIBILITY * Standard 2.4 kHz filter can be
narrowed continuously to 800 Hz with variable Bandwidth Control
(BWC). Narrow SSB and CW filters for 2nd and 3rd IF optional,
QRM SUPPRESSION • Other interference rejection features
include Passband Shift (PBS), dual noise blanker, 3-step RF atten-
uation, IF notch filter, selectable AGO and all-mode squelch.
8
10
11
12
13
14
15
NOTCH TRACKING • Once tuned, the IF notch filter will track the
offending heterodyne (±10 Khz) [f the VFO Irequency is changed,
DDS PHASE LOCK LOOP SYSTEM • A single-Cfystal Direct
Digital Synthesis system is utilized for very low phase noise.
CW FEATURES • Full break-in operation, variable CW pitch, built
in electronic keyer up to 60 wpm.
DUAL VFOs • Two separate VFOs for split-frequency operation.
Memory registers store most recent VFO frequency, mode, band-
width and other important parameters for each band.
200 MEMORIES • Memory capacity of 200 channels, each of
which store frequency, mode, AGC and bandwidth.
COMPUTER INTERFACE • Built-in RS-232C interface for
advanced computer applications.
ERGONOMIC LAYOUT • Front panel features easy to read color
LCD display and thoughtful placement of controls for ease of oper-
ation.
HEAVY-DUTY POWER SUPPLY • Built-in switching power
supply with Power Factor Correction (PFC) and "silenf cooling
system designed for continuous transmission at maximum
output
This device has not been approved by the Federal Commurkications Commission. This,
device is not, and may not be, offered for sale or lease, or sold or leased untilthe appf^oval
of the FCC has been obtatned."
JRC] 0apatRadiaCo.,Iid.
430 Park Ave., 2nd Floor New York, NY 10022 Phone: (212) 355-1 180 Fax: (212) 319-6227
CIRCLE 1S9 ON READER SERVICE CARD
THE TEAM
PUBLlSHEFt'EDITOR
Wayne Greeo W2NSD/1
ASSOCIATE PUBLISHER EDFTOe
David Cass idyNIGPH
I^ANAGING EDITOR
Hope Currier
SENIORnreCHMICAL EDITOR
Chaiies Warrington WAl RZW
EDTTORrAL ASSOCIATE
Joyce SaMeiie
CONTRIBUTING EDITORS
B\\\ Brown WBaELK
Mike Bryce WB8VGE
Joseph E. Cair K4IPV
David CowhtgWAILBP
Michael GeierKBlUM
Jim Gray W1 XU/7
Chuck Hougtilon WB6IGP
Arnie Johnson N1 BAG
Dl Marc Leavey WA3AJR
Andy MacAllister WA5ZIS
Joe Moell K0OV
Carofe Penv WB2MGP
JeWrey Sloman Nl EWO
ADVERTISTHG SALES MANAGER
Dan Harper
ADVERTJSING COORDINATOR
Judy Walker
1-603'924-0058
1-800-274-7373
FAX: 1-603-924-9327
GRAPHIC DESIGN
Suzanne Self
GRAPHIC SERVICES
Film Works, inc.
Hancock NH
QRAPHtCS MANAGER
Linda Drew
CIRCULATION MANAGER
Harvey Chandler
To subscribe: 1-800-289-0388
WAYNE GREEN, INC.
Editorial Officas
70 Route 202N
Peterborough NH 03458
1 -603-924-0056:
FAX: 1-603-924-9327
Subscription Servi
1 -BOO-289 0388
Foreign Subscribers
1^609-461-8432
Reprints: $3.00 per artfde.
Back issues: S4 00 each.
Whle to 73 Amateur Radio Today.
Reprints, 70 Route 202N,
Printed in the U,S.A. by Quad
Graphics, Thomaston. Georgia,
10
16
24
38
42
44
30
34
J^Amateur
Radio Today
Jul)' 1994
Issue #406
TABLE OF CONTENTS
vw»r-i-*«p<*«9 V v ■
FEATURES
The Global Positioning System
An overview..,,., ..„..„
World's Smallest 10 GHz ATV Transmilter
Build one on a PCB using only a few components.-.^ HB9SLV,
EMI/RFI Defense Strategies for Hams
Keep those troublemaking signals out of your mobtie ifistallatioa
A Delayed Video Trigger for Your Oscilloscope
Convert your surplus scope ,„„ ,„*.*.„„ ,.
Multiband Half-Wave Delta Loop (MHDL)
A simple 20-10 meter antenna wftti an 80-30 meter bonus
Ttie Improved Resonant FeedHne Dipole
A compact, low impedance, end-fed HF antenna that needs no tuner
REVIEWS
- •Dv viia*« h*
i d * I «« A t-^-k
,WA4BLC
HB9RKR
...N7MGT
,..XC3XM
WA6QeU
..W207H
S & S Engineering s Frequency Counter Kit
Now you can count frequencies til your hearfs content WBeVGE
The LDG Electronics FC-1
A small, flexible tox controller and CW IDer. ..K4CHE
DEPARTMENTS
$4 Above and Beyond
73 Ad Index
66 Ask Kaboom
63 ATV
61 Barter "n' Buy
62 Carr's Comer
67 Dealer Directory
17 Feedback Index
62 Ham Help
54 Hams wttli Class
50 Hamsals
60 Homing In
6 Letters
4 Never Say Die
82 New Prdctucts
S6 Packei & Comput
68 Pro|>agation
65 QRP
6 QRX
6$ Random Output
49 RTTY Loop
70 73 International
76 Special Events
Load your marine GPS receiver with highway maps and know where you're goings
Turn to page ro, (Photo by Gordon West WB6N0A}
FEEDBACK.^
^DBACKt
Ws like being there — right
here in our offices! How''
Just take advantage of
our FEEDBACK card on
page 17. You'll notkse a
feedback number al the
begi-nmng ot eadi artK^e
and cofumn. We'd Jike you
10 rate what you read so
tf>ai we can print what
tyo&soi tilings you like
best- And then we will
dmw one Feedback card
each month for a free
subscription to 73.
On the cover Hit the trait wfth the tcom GP-22 GPS receiver See thts month's cover story, 'Tha Gfoda/ Posrfioning
System, " starting on page 10. (Photo tjy David Cassidy NlGPH.)
Manuscripts CQntribuitpns In the torm oi m an u scripts wilti drawings and' or photographs ere welcome and wHE
tje considered for possible pubfication. We can assume no responsibility for loss or damage to any maleflal,
Please enclose a starnped, selt-address^d envelope with each submission. Payment for the use of any unsolicit-
ed material will be Tnade upon publication A premium will be paid for accepted articles thai have been sybmllted
etectronicaHy j CompuServe ppn 703tOJ75) or on dish 3^ an EBM compatible ASCII tile You can aJso cefiiact us
at the 73 BBS at (603) 924 9343, 300—2400 baud. 9 daia bfjs^ no panty, one Slop bit All contnbutions shouJd be
directed to (tie 73 editor^ offices. 'Uovt to WH& tqr 7J " gyldelfnes are availabie upon ret|uest US citizens must
indude theif Social Sacyftty rnmibef witti siibfiBtted maoyat^^^s.
73 Amatmir Ramo Today fISSN 10S3-M22) is (jtifaiT^ed monthfy tiy Vlfayne Green Inc.. 70 Rpyte 202 Nofthp
Peiert>OfOugh NH 0345^ Entire conienis i;i994 by Wayrke Green tnc No part of this pubrhcation may tse repro-
duced without wrttlen permisEan ot the publisher. For Subscription Services, wiire to 73 AmaTeur f^adh Todny,
P.O. Box 7693, Riverton NJ 08077-7693, Of calf 1 800'£eS-03ea, The suhscriplion rale Is: one year $24.97, two
years $39.97; Canada: $34.21 for one year, $57.75 for two years, including postage and 7% GST Foreign
postage: $19.0<] surface or $42 .QQ airmail additional per year. All foreign orders must be accompanied by pay-
ment in US lunds. Second dass posia^ paid at Peterborough, NH, and af addflional mailing offices. Canadian
second c^ass maiJ registration #178101. Canadian GST regisgatton #125393314 Microfilm Edition — Univemity
Microfilm. Ann Arbor MC 4aiOG POSTMASTER: Send address changes to T3 Amareur Radio Today, RO, Box
7633, R»vefUjn NJ 08077 769»3.
Contrad: Under tiie power v^^ested m me by the almigfity Oz, I oomrr^and you to get a Ide! Listening to your
erwjfess^ mindless ng babb^ is bonng Don t be a broken record. Get oK your center at gravity and try someitiing
new.
Editorial Offices
70 Route 202H
PetefbofDugh NH 03458
pnone: 603-924 OOSa
Advertising Offices
70 Route 202N
Peterborough NH 03438
ptTone: BOO-2747373
Circulation Offices
70 Route 202N
Peleilxjrough NH 03458
phone: 603-924'OOSa
J
73 Amateur Radio Today • July J 994 3
PIlHFiber 1 ofi your Feedback card
Ni
EVER SAY DIE
Wayne Green W2NSD/1
Here They Go!
Yes. I know you're busy figMing the
pEleups on 20m and could care less
about our 2400 MHz band. You're fo*
cused on the here and now and dcn'l
want 10 be bothered about five or 10
years from now. Let the future take
care of ilaelf,
The only reason w© hav© our coun-
try Is that a bunch at fanatics fought for
il a couple hundred years ago. They
believed in what Ibey were doing. I'm
sure glad there's no way fof them to
see what a mess youVe imtfe of ttieir
vision ana hopes. Yep, you. You're the
man. You re the one who has been re-
electing your crooks to Washington,
and It's Congress that's made the big
mess we're trying to cope with.
Well. Congress is at It again. This
time IheyYe grabbing 25 MHz of one of
your unused UHF barKJs arxJ putting it
up for auction, with tfi# proceeds to 90
toward supporting even more Congres-
sional pork. They'll get billions for it.
Our 2390*2450 MHz band is the first
on the block, with recommendations for
selling oft the 2390-2400 and 2402-
2417 segments. They're graciously
planning to leave us the 2400-2402
segment tor our satellite commumca'
tions. They've also targeted 2300-2310
for later s^e. Thatll carve 35 MHz from
our 70 MHz alkxation, Half!
tn 3 few years well either have a
healthy amateur radio hobby which is
largely satellite oriented or well be a
vague footnote in the history books.
The world Is going high-speed digital
and leaving us behind in the dusL
So wt^at can you do dbo^rt all this?
Prtibably not much. Yov've bet the farm
on the ARRL and they Ye unlikely to
take any action that could change
things. Congress es run by bnbes. with
the biggest bribes going to the subcom-
mittee members. Let me be blunt
... how much money have you person-
ally donated to your congressmen's re-
election fund? rm wiOirtg to bet that all
500.000 Of the hams who may Still be
alive have donated well under S50^Q00.
Ten cents a head- Wei J. a dime may
have been big money when old man
Rocketeiter was handing 'em out in the
1930s, but we don't even txither to lean
over to pick up a dime on the street
these days. With Congress you get
what you pay for and not anything ex-
!ra. They know you're so stupid you will
continue to re-elect them, so why
sHoutel they care wttat you think?
Now. if you could sta/1 getting sorrte
petitions going among your family,
friends and co*workers, promising to
unelect them if they sell off your her-
itage of ham microwave frequencies,
we might get somewhere. It would take
ham clubs in all 50 states to puil it off.
One thing you can bet on. I'll be watch-
ing the ham club newsletters, looking
for some signs ttiat someone out there
gives a damn about the hobby. If eveiy
ham club in the country started getting
petitions signed, with copies to their
congressmen and me ^ we might end up
with bigger satellite bands instead of
diced and sliced babney.
Or you can wait for the ARRL to do
something, which 1 doubt will ever hap-
pen.
What will I do with a ton of petitions?
I've been a registered Washington lob-
byist for over 20 years now. so I know
exactly what to do. I've been down
there before waving a sheaf of petitions
and watched the reaction. That was
what got us the hearing before the FCC
Commissioners 20 years ago, the one
which resulted in the biggest changes
in ham rules in the history of the hobby.
That's when we got back our repealer
lighls.
Yes, Congress Is njn tiy bribes, but
tfiey also am influenced by cartons of
petitions. Heavily influenced. If they get
uneiected they re suddenly off the lob-
byist gravy train.
But heck, it's only 25 MHz of a band
we aren't using, so who cares. Right?
Never mind that the camel's nose is in
the tent
Poor^ Dumb Wayne
A few years ago t got an Interesting
letter from George W9EJY proposing a
ridiculous new modulation approach.
Imagine being able to put a 75 MHz FM
signal out on an AM broadcast trans*
mitter! An obviously crazy idea.
But George had stirred up an Idea
f^d had years before , . , an idea thai
seemed logical, but if so, why wasn't it
being used? I think I even wrote about
this in an editorial mayb€ 20 years or
so ago. So I ran the »dea by a scientist
thend of mine to see if he could shoot it
down. He hemmed and awed.
What George has done . . . what Td
wondered about years ago . . . was tak-
ing an audio modulated FM signal and
divfdJng it down Let's say you want to
have a n«:e. full frequency aucSo signal.
We coufd even start with the normal 75
kHz commercial FM bandwidth, modu-
lating it at 100 MHz, right up in the mid-
dle of the FM band. Now we divide rt by
5 twice and we've got a 4 MHz signal
with 3 kHz bandwidth. Any reason we
can't transmit that on 75m and have
one heck of an FM channel?
To receive it you'd want to multipfy
times 5 twk^. This woukj take your 455
kHz IF signal and move il to 284.375
MHz. A local osciliator at 273,675 MHz
would give you your 10,7 MHz IF signal
for any FM receiver to detect.
Well, if we can do that lor FM, how
about a 6 MHz-wide TV signal? Well
we*d have to start at around 2500 MHz
ar>d divkle down by 5 four limes, That
would again give us a 4 MHz output,
but with ±9.6 kHz of modulation. Not
bad for ATV on 75m, eh?
Now please tell me why this won't
work. Then ill pass (he word to
George, who has tested Ns F1V1 idea on
the air with a cooperating AM broad-
cast station and found it to work just
fine. He's been exhibiting at the NAB
conventions, looking for a sponsoring
company to get involved. He's found
that ff the AM station keeps its AM
modulation at around S5% tfrere is no
detectable interference between the
AM signal and the micro-mod ulated FM
signal on the same carrier.
As George points out. the exciters
used for early FM transmitters started
out at around 115 kHz with ±87 Hz
phase modulation and then multiplied
that up 864 Umes to the output channel,
Sduce for the goose .
The concept was good enough to
gel George a Technology Award from
The Society of Broadcast Engineers in
1992. But is it enough to gel you to give
it a try?
Progress
5o here we are in 1 994. And hem I
am using a Macintosh PowerBooK for
most ol my work. And here I am without
a simple program to keep track of and
display the sales of my enterprises.
This is ridiculous!
The first practical microcomputer
was the Radio Shack TRS-80, which
debuted In August 1977, just two years
after the first micro was announced.
The first was ttie MITS Aftair 8800. but
that lacked a few things. It came in kit
form and had no operating software at
all. A few months later Bill Gates
showed up at MITS in Albuquerque
with his |ury-rlgged BASIC, The way \
recall it. he'd written a BASIC inter-
preter for the 0008 chip as an exercise
in his computer course at Harvard.
When the Altair came along, desper-
ately needing sornething to make tl do
more Ihan be an expensive paper-
weight, he cobbled h^ interpreter so rt
would work on the 8030 chip, left
school, and went to work for MITS.
He's doing fairly well.
Commodore came out with a PET
microcomputer in around March 1977.
but it had a stupid square keyboard,
and a marketing plan designed to
screw any dealers who sucked into try-
ing to sell it. My recollectioo is that Jack
Tr^mJel, the president, set up his own
separate nnail order finm. Contemporary
Marketing, in Bensenville, out near
Chicago, just to sell the PETs. He re-
fused to let Commodore run any ads
for the computer, with only his rrflii or-
der firm advertising. I visited the factory
in California where 1 was told that only
alter his mail order company had all ttie
Inventory they needed would Com-
modore ship any units to dealers.
But to use the PET you had to load
BASIC from a cassette, and so on.
Slow. By the lime Radio Shack an-
nounced their TRS-60 Model I, the cus-
tomers were ready for It.
I realized that the only practical way
to provide Ihe software these micro-
computers were goirig to need was to
manufacture and sell it in quantity. Up
until then we had the mainframe com-
puters, starting in the million-dollar
range, compiele with horrendously ex-
pensive software, also running in the
million-dollar range. Then came the
minicomputers In the $100,000 bracket.
The software for these systems was
custom -developed for each user and
also ran around $100,000 on the aver-
age. So I figured that now that we t^d
$10,000 computer systems we were
going to have to get soft- ware costs
down too, and that meant mass pro-
duction. That's when I started Instant
Software.
My approach was simple. I got the
readers of my magazines to send in
software ttiey'd developed for possible
dislnbutk»n. I set up a lab with around
30 work stations so we coukl cover the
m.'^st popular micros. Incoming soft^
ware was then evaluated by my people
and the best of it was put into shape for
production. We started out with a lunar
lander, and went on to develop all kinds
of games, educational stuff, and quite a
few rather good business programs.
Our Typing Teacher won prices, as tfid
our geography prograrrts^
One of ttve best was Business Anal-
ysis, Though that was designed for the
Model I. and later it was updated for the
Model til. II was so far beyond anything
Tve seen since that it is fnjstrating. I
sure wish something like that was
available for my Mac. If there's a pro-
Conttnued on page 74
4 73 Amafsur Radio Today* July, 1 994
MODERN, MULTI-BAND ANTENNA SYSTEMS
MOBILE
ANTENNA
PRODUCTS
Modern, tiigh-pertormance stations use COMET Antennas. Duplexers, Triplexeis and Accessories! COMET products are designed 1o provide
an exceptional level of signal quality and coverage area. Whether operating mobile or from your base station. COMET products make you
sound good. No other product line has the selection, convenience, quality and performance!
DUAL-BAND MOBILE ANTENNAS
TRI-BAND MOBILE ANTENNAS
FL-67S Duai-&and 14S/446MHz v\f/Fold'Over, No Ground Plane Required
fimn&Wavr VSWR: MaxPowBr: Unglh: CcnnedDr
146MH?4 5dBj '^i wave 1 5;1 orEess 150 watts A'iv Gold Plated Pb259
446MHz 7,2d8i'^/B wave X 3
CX-224/^4IIMQ Tri-teid 146/22a/446MHz. w/Fold-Dver. No Ground P\m Required
Gatn&Wave: VSWfl: MaxPovrin Lengfti: Connedor:
146MHz 2.1 SdBi^y^ wave !i:l lOOwate 3' PL-25^ofNM0sty^E
220MHz IBdBi 'i^ mvt or less
"^#^
FL62S Dual-Band 146/446MK? w/Fold-Ov&r, No Ground Plane Required
Gain & Wave: VSWR: MsxPowtr: Lfinglfi: Conneclor:
146MHz 3 5dBi l{' wave 1.5:1 or less 150 watts 3^ &* Gold Plated PL'2S9
446MHz 6.0dBi^-^ wave X 2
S8*7/SB*7||M0 Duai-Band 146/44€Mm w/Foid-Over, Ho Qtomi Plane Required
OaiR^Wavn: VSWR: Max Power LflOflUi: Cuiamcim
umm A 5dBi ^ mave 1.5:1 or less TOW FM AT PL-259 or
center icyd€cl MUO^
SB-&/$B-&MMO DtiahBand 14W4l6MHz w/foKl-Qver. No ljrour>d P^e R&quir^d
GainiWavfl! VSWR: Hai Power Ltngtii: Coniiec^ori
t46MHz 3 OdBi ''^ W3ve 1.5:1 or less 120WRyi m ^1-259 or
446MHf5 5dBi^^vaveK2 NMO style
FM5S TrhBand 52/146/446MH2 w/Fold-Over
Gain & Wave: VSWR: Max Power:
62 mz2A 5d6i % wave l . 5:1 1 20 W FM
1 46 MHz 4.5d8i l*^. wave or iess
446MH2 7.2dBi % wave x 3
Length:
4' 10"
Goi^nectur:
PL-259
HF MOBILE AND HT ANTENNAS
IU'4S Quad-Band HFiS/' (20)/1 5/1 Z/TO Meters w^ld-Over
Wsvi: VSWFI:' Weight LenglFi: MaxPowen Connector:
*i4wave 2:1 or less llb.MoL 4 4' 120WSSB PL-259
(2oaw ssa 28mhz)
"W4BS0pliona] 20 Meter Co«
$B-2/S6-2NM0 Du^hBand146/446MHz
G9 in S Wave: VSWR: Max Pt^wen
146MHz 2,15dBI V* wave 1 ,5:1 or less 60W FM
446MHz 3.8dBrJ^ wave
Length:
1B^
Donnector
PL-259 Of
NMO style
B-10/B-10NMO DLiahBand 146/446MHz, Cellular Look-a-like
Gain & Wave: VSWR: Mai Power: Length: Conneclor:
146MH2 0dBr/4wave 1.5:1 orJess 50WFM 12* PL-259 or
446MHz 2 I5dei '/& wave Um styfe
SH-K Super Flexible 146/446MH2 HT Antenna
Gain & Wave: Ma; Power: Lenglh:
146MHn.5dBiVjwave 10 watts 15,5'
446 MHz 3i{iBf^/lW3\/ex 2
CH-7Z2SA High Gain HT Anienna
Gain & Wave: l46MH2 3-0dBi ^A wave
446MHz 5.5dBJ^y| wave X 2
WaK Power: 50 watts
Length: 35*, 2 sections. IS' each
Cannector: 6KC
ConneitBr:
BNC
GN-32 Miracle Baby
146/446MHzHTAr}tenna
Gain & Wave: OdB /4 wave
Max Power: IQ^vatts
Lengtli: t,75"
Corrneclar: Bl^C
DUPLEXERS AND MOBILE MOUNTS
B-20/B-2QNMO Dual-BarMi 146/446MHz, Cellular Ap pea rarn^,
Nq Groitnd Plane Required
Gall! Wave: VSWR: Msi Power Lenfth: Conneclor
146MHz 2.1 5d8it^ wave 1.5:1 or less 50watt$ 30* PL-259 or
44611Hz S^OdBi -^ wive x2 NMO s!yte
SB-25/SB-25NM0 Mono-Band 14€MHz vir/Fold-Over. Ho Ground Plane Required
Gain ft Wave! VSWB: Max Power lengHu Cd<nnettort
146MHz 4.1dBiH wave Uiloriess tOOWFM 4'9r PL-259 or
center loaded NMO s:tyle
COMET products are avail3h!e ffom
most major dealers. Far customer
service, or a complete calalog,
please call us aia00/dBZ^2611.
We're confidenl COMET pruducls
and accessories will enable you to
enjoy Amateur Radio to its fullest!
'^#^1'
MINI SPEAKER/MIC
nil en
NCG COIVfPANIES
1275 North Grove Street
Anaheim CA 92806
(714) 630 45i1
FAX (7141 630-7024
HMP2K/F
Minrspkr/mfcfeafturingfulf
TX/RX quality"
Ughf weigfTt, ■eiftr&meiy
smatl: I'sS" with coHar
^fxM €lip.
HM-P2K- Kenwood Versioo
StanilvdrMica%tc.
CF-4106K, l,J,
146^446MHz
1.3-l50IIH2.0W«»wPeP
40[}'54{]Mmi D.2dB. SOOmt PEP
Is9lali(3fl: 6(]dB
COiNECTOf^
416av 41601 *^m
Otim SO-239 SO-Z39 Sa23S
Im ta: Pl-25f Pl-259 50-239
Hgh In: PL'259 N-Miie SOBS
RS-82fl
Heavy'Du1>, Low Prof lie
Trunk Lip or Haicf: Back
Mourt. Rut^ber■t;aate^j
base protects vehicle
paht.
3D4M StBndard
Cable AsseJTibiy
1 3.5 feflt of low hKS ccKix,
GoldfHateE3UHF(Pl-25a^'
SO-^) conrtectors
3D5M standard
Catile Asssrnbfc
Same as 3D4M, but 17
feetofccku
RS-21
D-azfr etc:)
rTKMJoLimusabli
coatidtsase
[»rQt£ct5¥et«ie
WMW
WlndQvCliD
Mount
11.5 feel of irigii
qjjalilY CDajL
Gold-pUted UHF
Conns, tor
Antennas up to
40' in JieiflttL
CK-5M mm
Cable Assembly
13feeidauo^snit>lded
very tmw loss am + 1 ?
RG'taatEficinc&ax BiM
plated UHFlPL-Z^g^'SO-
239i coEinectors
CK-5MS OekMe
Sam&asCK-5ll,Ml7
^ERVI
Lehers
Number 2 on your Feedback card
James W. Searcy WA5WRE,
Poplarville MS In July of 1992 there
was an amateur in Picayune. Missis-
sippi, who came up on the locaJ re-
peater there and used at! kinds of four-
letter words, complaining about a wom-
an driver cutting him off in traffic. As he
was spouting off over the air, I calied
the FCC office in New Orleans and iet
an FCC engineer listen for a solid five
minutes. He toid me that there was
nothing the FCC could do* for they
could not "define" wfiat was obscene.
Well. I cHewed thai, and after choking a
few times I managed lo swalfow it
Now (April 1) I've had a non-ham
come up on my machine here in
Poptarville. use our autopatch. and
never sign. We caught the indFvidual.
called the FCC. taiked to t^^ ^me en-
gfneec and were told. There's nothing
we can do, for we dEdn t witness the
QSO." Not only that^ but a business
wtiose owner is an Extra Class ama-
teur sold him the radio,
Weil, needless to say, this upset me,
but what really hurts is tiiat word got
out about the FCC's "non -action,- and
now one of my students has dropped
out of class and is operaiir>g on ama-
teur frequenoes with a bogus caJi, stat-
ing. "Why worry? The FCC won^ do
anything to you. so w?^y go tlirotigh the
Noodache of working for a license?*
IVe been an an^atetrr (or 42 yeers
aftd frankly, Tve reached the point
where I cani blame him. It's like goir>g
to a war without your leaders. What are
you supposed to do? With no FCC
backing, there is no chance of winning.
I don't operate HF at ail» but it I did I
think I would modify it for CB so tiiat
wiien the lime comes 11! be ready.
James — You haven't t^een reading
my editorials. TsfL
As Vve expfained. the FCC is under-
staffed and underpaid, and doesn't
want to be bothered with Mmateur ra-
dio, if we aggravate them very much
tt^yU get more interested in ending the
hc^y Aitef all, the FCCpeopie get no
Imrmftt from hams.
Were no ion^r ifving tp to any part
Of our charter, so the less we toother
them, tt^e longer well be able to use
the t)iftions of dollars in spectrum we've
inherited.
The fact fs that when there is a focal
problem it's up to the iocal amateurs to
take the soiution of the problem as
their responsibility You can't expect the
FCC to spend money to heip. After all,
how much money are you paying for
ywr license? Zilch. And what etse are
you contributing to the commonweal?
Not very mucit
The best rule is not to poke the bear
while it's sleeping.
73.., Wayne
Itttvln Elliott K0VNP, on the 73
BBS Wayne, I wan! to thank you for a
few of the tilings you have unknowingly
given me. You and your mag, In the
early small -size fomriat, got me inter-
ested in ham radio, via the articles and
From the Ham Shack
your grasp of the ham community. You
gave me the chance to enter through
reading t^e various articles and, of
course, your comments.
t bought your lapes in 1976 to team
lUorse code. You had a rather odd idea
of sending fast, with the spacing in the
range needed. With me it was 5 WPM
that got me into the area I thought 1
would not be able to attain. The numer-
ous magazines that my Elmer gave me
to read, yours and others, were what
got the Iheory lo begin to make a bit of
sense. But no matter what subject t
wanted to rind, articfes in your 73 mag-
azine were what I came back to. Your
trips and DXpeditions allowed me and
otiiers ttie chance to see what tl^is t\ob-
byisallatXHJt
I went on to get my General ticket
and worked about 175 countries. Via
moving and a divorce I lost about all of
my gear and my QSL cards. I lost
yours tn a fire, and that was probably
one of the most treasured of the bunch.
I had the early Ciipperton. Watvis Bay^
on the second day they used that call,
and others* but my W2NSD/1; card was
at the top of the iisl. You were nice
enough to send me a card a Few
nnonihs back to replace the one I lost,
and I thank you^
Last Saturday I took my Advanced
test, which I passed with ease, in a
large pan thanks to reading and leam-
rng. Even at age 41 my dreams contin-
ue, thanks to your magazine. My fr-
cense was feinstated from my tirsl call
(WB0YHG) to N0VNP because i
strayed from the hobby that I have
grown to fove. But, finding your bigger-
size magazine on the newsstand one
day about two years ago relit the fire
that i hadn't realized had gone out*
Wayne, thanks for ttie memories
that you have gtven me and for the en*
joynrieni that each month i discover in
the pages of your publication, Dont
change now — I'm too old to be con-
fused.
By the way. I am getting remarried
on August 6 and my future bride will be
3 ham by then as welL Sne is taking
her Tech (with code) class from a local
group, and in large pait I can thank you
for that as well. Your edilonals aboul
education have a very speaiat meaning
to us. May ali your skip be long and the
scuba diving safe.
Gary Moeller N8WVV, from the 73
BBS I love your editorials. They are
one of the first things I read each
month when I get my copy of 73.
Please keep prodding us — heaven
knows, we need someone to keep us
thinkir>g. The rest of society seems to
want us to go brain dead ar>d you are
hejipir>g to keep us alive.
(rving L Chidsey, Havre de Grace
MO Wayne. I was peoising my son's
copy of the Apnl issue of 73 and f>oted
your column on "Good Science and
Bad Science." The quality of what
passes for science in public discussion
has long been a concern of mine. I am
gtad to know thai it ts also a concem oF
yours, but I am puzzled by your choice
of examples, for we seem to be on op*
posiie sides of several issues, and i
would like to know what your criteria
were. For most of iny professional ca-
reer I was part of the Bockel/Upper At-
nrtosphere program at the Army's Bal-
listic Research Laboratory, classified as
a physicist* or a research scientist, or a
research engineer at the whim of the
personnel office. My criteria are that as
much as possible I check with the ref-
er eed journals (more difficult since I fe-
ll red two years ago), and that \ under-
stand the underlying science. Now that
I can no longer easily read refereed
journals, t use The American Scientist,
publistied by Ssgma Chi, The Scientific
American, Science, and Nature when 1
can get them, and books published by
recognized scientists. I don't own a
copy of Corn's booK but if I c£d, I woukf
read it to check hjs understanding of
the Issues, not to inpmve mine.
My reading of the sctentifK: joumals
tells me that scientist are worried
about acid rain and rts effects on the
more fragile ecosystems. The first arti-
cles about the increase in atmospherio
CO^ appeared in the Journal of Geo-
physical Research, etc., during the mid
'60s. and scientists have been con-
cerned about the probable conse-
quences, -giobal warming and a rise in
the sea level, since the earty 70s. It
was also the scientists who discovered
the ozone hole over the South Pole,
and they have made great strides in
understanding what causes it The at-
mospheric science community StitI be-
lieves that a nuclear winter was the ex-
pected aftermath of an all-out nuclear
exchange between the United States
and the USSR- Frankty, t*m qyite happy
that we didn't try that experiment. After
the Gulf War, one very earnest, very
prolific, and very wrong nut flooded
several discussion groups on the Inter*
net with predictions of doom because
they thought the very extensive smoke
clouds from the burning oii fields would
cause a Gulf War winter There was a
quite measurable cooling where the
ctoods persisted, about what the ttieory
predicted, but it went away when the
fires stopped. To that extent the nucle-
ar Winter theory has been validated
Yoor ottier examples are from fields
lurttier from my expertise, but I believe
that nrx^si of them are valid concerns. I
agree that the Alar scare was a panic
attack that grew because the scientists
hadn't done theif research yet It is true
that we won't run out of oil 'til quite
awhile after the turn of the century, but
we now have to do much of our drilling
in very dangerous and inhospitable
places, and it is getting harder and
harder to find major oil fields. We are
losing topsoii and we are paving over,
or developing, much of our best crop-
land: the county I live tn has Ic^t over
half its farmland to development in the
last 40 years. There are areas m our
country where the water table has
dropped several hunched feet ove^ ttie
last few decades- The example that
comes to mind is the OgalJala aquifer
in the Rams states: on Long Island,
sea water has moved in to replace
potable ground water. ( think that such
examples can be reasonably described
as using up our ground water.
Some other examples of bad sci-
ence. Of at least prematurely an-
nounced science that didn't pan out.
ai^ the 4th state of water, cold fusion,
unlimited oil, and laetrile. Several of
them were trumpeted by the press be-
fore they had gone through the scientif-
ic review process Unfortunately, the
loudest protagonists on both sides of
these questions tend to be the most ir*
responsible, and the scientists may be
left out of the public discussion.
Remember, we do our science out
In the open, and In some cases the sci-
ence gets communicated to the public
while it is still being baked: the press
likes to get its stories while they are still
hot, without waiting for all questions to
be threshed out In the review process.
In several of these cases, the news
was published too soon; the "good sto-
ry* was a false lead, an emor which the
scientific oonmrtunity corrected as soon
as it could. Ttie alternative is to study
the phenomena in secret, and only in-
form the public when all the research is
done and all doubts removed. I don't
think thai secret science is either possi-
ble Of desirable in a tree society, and
you would be among the first to obj:ect
if it were tried. Absent carefully-con-
trolled release of only assured results^
we have to let the work in progress
hang out in public and take our
chances that the public will some!inr>es
be led astray. Again, I would like to
know what your criteria were for choos-
ing your examples so I n\ay understand
why we ditfef.
Irving — Yes. we do differ But if yott
ck> some homework. I think we 7/ be *?
agreement. I suggest you read Envi-
ronmental Overkiil by Dixie Lee Ray.
the former Governor of Washington
and Chairman of the Atomic Energy
Commission, Assistant Secretary of
State, etc. The publisher is Rsgnery
Gateway Commission, $20, 260 p.
Then read Ecoscam by Ronald Bailey,
St f\^artin's Press, 228 p.
These two books, ptus several oih'
ers I've read, alt agree that the ozone
hole is baloney and ditto global warm-
ing and the coming ice age. Even the
nuc^ar winter data has tte^n seriously
challenged in Scientific American, a$
has acid ratn. Ray demolishes that
tMi^too. too (pages 147-150}.
Remember that no sclenfific issue
can be resolved by strongty-hetd
belief, no matter how eminent the
authority.
Ymj are ir\deed out of touch when it
comes to cold f us ton. Tsk! The pre-
miere issue o/"CoEd Fusion" magazine
is in my hands: 100 pages, with articles
by several well-known scientists.
CopiGS of the magazine are $W, If
you're interested in coming up to speed
on something you believe didn't 'pan
out"
You mentioned Laetrile, which
makes me wonder how much you've
read about it. Not much. Ill i?ef. How
a£x>ut what the AMA did to t-loxsey and
to Krebiozen? You 11 want to read
Racketeering In Medicme. The Sup-
pression of Alternatives by Dr. Carter,
Hampton Roads Press. Si 3. 360 p.
Goodt^x>h.
You also might read fmpure Science
by Bell, Wiley $23, 300 p. Cheers .^^
Wayne
5 73 Amateur Radio Today • July, 1 994
You get more feaftures for your dollar with the
REP-200 REPEATER
A fully microprocessor-controlted repeater with autopatch
and many versatile dtmf control features at less than you
might pay for a bare-bones repeater or controller alone!
Kit $1095; w&t only $12951
• Available for the 143-174, 213-233,
420-475, 9D2-92a MHz bards.
• FCC type aceaptec* for commerdal
service inl50 & 450 bands.
*$lK courtesy beep types, including
two peasant muttitone bursts.
• 0p€fi or closed access autopatch,
toil-calf restrict, ajto-di&connect
• Reverse Autopatch, two types.
• OTMF CONTROL: Over 45 functioris
can t>e controlled by 4-digrt citrnf
comniand, via radio or telephone.
• Owner can ir^hibit autopatch or re-
peater, enable either open or closed
access Jor repeater or aytopatch, and
enat>le to^J ca^ts, reverse patch, ker-
chunk ^t^, site aiarm. aux ruvr.
* Change cw speed and tone, beep
deiay, ^ iktmit, and courtesy beep
type at any flnw by owti&r password
protecteo dtinf oofnmancls.
* Auxiliary receiver input for corrtrgf or
cross finking repeaters.
* Color coded LED status Indicators
REP-200T Voice Message Repeater, as above, except
pndudes Digital Voice Recorder. Altows message up lo 3D sec to be
remotely recorded ofl the air and played back at user request by
DTMF command, or as a penodJcaJ voice »d. oi^ boiti. Hi $11 45, wit only $1395
REP-200C Economy Repeater uke hep-200, except uses
COR 6 Controller (oo DTMF conlTol Of autopatch) Features real -voice
ID KitontyS795,w&tSl095
REP*200N Repeater, want to use your ACC cofitroller. etc? No problem!
We'll make you a repeater with rf modules only. ,„„„^„.... Ktt only $6^, w&t $995
XMTRS & RCVRS FOR REPEATERS,
AUDIO & DIGITAL LINKS. TELEMETRY. ETC.
AUo available in rf-tighl enclosures* and with data moderns,
FM EXCITERS; 2w continuous
duly TCXO S Ktal oven options
fCC type sccept&i forcom'i
high band & uhf.
- TA51: 5C^54, 143-174, 213^233
MHz.. kit $109. w&t $189
- TA451 420-475 MHz
ktt $109. w&^ 3183.
. TA901 902-926 MHz,
t0 5Wout).wSlS219
VHF & UHF AMPUFIERS.
For fm, ssb. atv Output levels froin
10W to tOOW Several trnxiels startir^g at S99
FM RECEIVERS:
i R144/R220 FM RECEIVERS tor 143^174
or 21 3-233 MHz Sensrtive front end.
0. ISuV, both crystal fi^ ceramic if fillers
plus hellcai resonator front end
Tor excepts nai selectivity >1OOd0at
± 12kHz [best avaifabfe anywhere ►)
Flutter-proof hystefesis squeEdi:
lutS149. wat S219
• R4S1 FM RCVR, tor 420-475 MHz
Sntar tc above ..kit $149 w&i $219.
• RMl FM RCVR, for 902-926MHZ
Trkple-conversfon, SI 59 w4l S249.
• R76 ECONOMY FM RCVR for 28-30, 50-S4. 7S-76. 143-174, 213-233 MHz.
w/o hehcai res, rfjetectivity >lOOdB at ± 12kHz Kiis $129. wat $219
^f^/ R76 MONITOR FM RCVR Kit for 10M, 6M, 73 MHz. 2M. hl-band. Or 220
MH2, IF selectivity SOdB at ±12kHz Great for monitoring repeaters,
amateur callrng frequenciee, or packet radio frequencies, and for listen-
ing to commercEal two-way radio, police/fire frequencies, or weather forecasts,
Good staffer kit, too; easy to assernbfe and airan. ..„„,._„.„,...,... Kit only $591
N^Wh
- R137 WEATHER SATELLITE RCVR for 137 MHz Speaal if fillers tailored for
wdefoand frn Lowest cost receiver avait^le ., lot only $69, w&t $149.
• We also have pfeamps and feceivrng converters for 137 MHz, ^x! we carry tfte
vyeaf/ief SateJWe HamMxx^ by Ralph Tsggan
• Buy at low, factory-dfrect net prices and savef
■ For complete info, calJ or write for free catalog.
{Send $2 for oversess air mail)
■ Order by mail, fax, or phone {5-i2 am. i^pm eastern timej.
• Mm, S5 S&H charge for frrst pound pCus add't weigh! A insiirairtc«„
• Use VISA. Mastercard, check, or UPS C.O.D.
ACCESSORIES
COR^3 REPEATER CONTROLLER.
Features adjus^tabie tail and lime-oui
timers, solid-state relay, courtesy beep,
and iDca I s pea ker amp mmr ,, ... kit $49
CWIO. Diode programmable any time ir
the field, adjustable tone, speed, and
tjrner kit $59
COR-4. Complete COR er>d CW1D all
Ofl orre board CMOS logic for low power
consyjnption EPROM programmed
specify call -„.„„.„_iat $99, w&t SI 59
COR-6. COR & /*^li'S^]R^
Real Voice ID jf'^Te^i'Mi'
on one board, &J:^> !, **
Digital ic records ^t'^^^'—S--^^^ v
up to 2€ seconds •* ? p ^A"^^
of your voice tf
Can record mult^le id messages Tail and
time-ooi timers, oxjrtesy fc»eep. solKl-state
refay to key transmittef kit ^9. w&l $149
Versatile DVR-1 DIGfTAL VOICE
RECORDER Module As a voice lD*Bf
for repeaters, records your voice, using
the built-in microphor>e or external mic
Just the thing for fox hunt xmtr id! May
also be used as a contest caller to play
back one or more messages through your
transmjiter at Lhe press of a switch. Used
as a radio notepad, it can record the
audio output of a receiver — up to 20 sec
of anything you migM war^t to recall later
Play back as
/^■^^> oR^ as you
* ^^^^ laie ihfough a
<^jlMF .^vlS^7 speaker B(-
' * " ^^ ' y y tensive man-
_^ "■^w to u se m ult i p I e
■^^ 'i .^^/ me ssa ges an d
^^/ adapt to many
appJfcations,
TD^ SELECTIVE CALUMG Wod^
yle. Versatile dtrrif controHer with 1
latctiing output Mutes speaker unlii
someone calls tjy sendir^ your 4-dfgit tt
code. Or use it wrth a )or»g It zero digit 10
alert anyone in club Also may be used 1o
control autopatoh or other single device
.■.„.„..„,,.......■ kit $49, w&t $79
TO 2 DTMF DECODER/CONTROL-
LER. 16 digits, programmable, toli-oall
restrictor, Can turn 5 functions on/off
.kit $89, wired & rested $149
AP-3 AUTOPATCH, Use wfth TD-2 /or
r^}eater autopatcii Reverse patch and
phone line rerriote control are std
krt $89, wired a tested $149
fiiPl StMPLEX AUTOPATCH Timir>g
Boanl Use with alKive for simpleK oper-
ation using a transceiver kit $39
TD-3 SUBAUDIBLE TONE DE-
CODER/ENCODER. Adjustable for
an'^ tone. Especially for repeaters^ with
remote control activate/deactivate provi-
sions kit $29, wired a tested $59
DATA MODEMS
Ma-202 FSK DATA MODULATOR «
DE-202 FSK DEMODULATOR. Run up to
1200 baud digital signals through any fm
transmillef & ,-5^^ -^^ i-i-*— t__a n
receiver
Radio-Jink
computers,
telemetry^
kft ee $49. W&t ea $79
9S00 8AUD DrGITAL RF LINKS.
Low-cost packet networking system,
consisting of M0-9& Modem and special
versions of our 144, 220 or 450MHz FM
Transrmtlers and Receivers. irHerface
directly with most TNC's. Fast, dtode^
switched PA'S outpot 15 Of 50 W CALL
Low CostGaAsFET
PREAMPS
ONLY $59
FEATURES:
• Very low noise: 0 7dB vhf, O.adB uhf
• High gain: 1 3-2CJdB. depends on treq
• Wide dynamic range - restst ovedoad
• Stabfe: low feedt^ack duat-g^e FET
*Specftv tuning range ?^30. 4^5G. 137^ 152,
152- ^72, 2r&-330, 4O(hi70, m^JQmtJ^ii.
LNW-(*)
MINIATURE
PREAMP
ONLY $29 kn. $44 mkef5ii9ti^
• GaAs FET Preamp simrtaf to LNG, est-
cept designed for low cost & small size
Orily S/S'W x 1-5/8'L x 3/4'H. Easify
mounts io many radios.
*Sf)ecify turifftg jsnge; 1^35, 35 55. 55-Sflt
90-120, t20-lSO, t50-2Q0, 200-270, 400-500 MM2
LNS-(*)
IN-LINE
PREAMP
ONLY $89 kSi.$119 w]r«dAl«^M
• GaAs FET Preamp with features similar
to LNG series, except automatically
switches out of line during trai^smii.
Use wFtn t>a£e or mobile trartsceivers up
Io 25W, Towe<^ mountir>g brackets ind.
'Tuning r#rtge. 120- 175, 700^240^ Qf4iX>-5O0.
HELICAL RESONATOR
PREAMPS
GaAs FET preamps
with helical reson-
ators reduce inter-
ned & cross-taand
interference in crMcal appicatJons.
MODeLHflG^*), $80 vhf/SIWuht
*S^3ecrfy nini'ng range: 14?-JStD, lSB-t^ 1G2-
f74, t1^3^, 42a^fm.
RECEIVING
CONVERTERS
LowTiDtse
to
snduhf
bands ona
IOM recover.
• Input ranges avail: 50-52. 136-138,
144-146, 145'.147, 146 148, 230 222,
222-224 MHz, 432434, 435437,
435.5-437,5, and 439.25 (to chan 3),
* Kit less case $49, kit w/case & BNC
jacks S/4, w&t in case S99.
TRANSMITTING
CONVERTERS
XV2forvfTf amlxV4fof uhf. Modeteto
convert lOM ssb, cw, fm. etc !o2M, 220,
222. 432, 435, artd atv 1W output
Kit only $83. PA s up to 45W awaflable.
pur 5Jnd Vt-ar
ronics, inc.
6S-D Mout Rd; Hilton NY 14468-9535
Phone 716-392-9430 (fax 9420)
QRX . . .
Number 3 on your Feedback c^rd
FCC Amends Message
Forwarding Rules
The Federal Communications Commission
has acted on RR. Docket 93-85 and has re-
laxed the Amateur Service rules lo enable
conteniporary mes&ag© forwarding systems to
operate at hundreds of characters per second
while retaining safeguards to prevent misuse.
A message forwarding system is a group of
amateur stations participating in a voluntary,
cooperative, interactive arrangement where
communications from the control operator of
an originating station are transmitted to one or
more destination stations via forwarding sta-
tions, which may or may not be automatically
controlled.
Currently, the control operator of each sta-
tion is held individually accountable for each
message retransmitted, resulting in unneces-
sary content review and delays. The Ameri-
can Radio Relay League stated that the obli-
gation of the control operator of the first for-
warding station should be the establishment
of the identity ot the station originating the
message. Only when this is not done should
these control operators be held accountable
for improper message content.
The commission agreed, and thus, the FCC
will hold accountable only the licensee of the
station originating a message and the li-
censee of the first station forwarding a mes-
sage in a high-speed message forwarding
system- The licensee of the first forwarding
station must either authenticate the identity of
the station from which it accepts communica-
tions on behalf of the systenv. or accept ac-
countability for the content of the message.
T7VX Westlink Report. No. 670, April 21, 1994.
See The Light
A young Missouri company has announced
what they say is the ftrst fiber optic cable sys-
tem for home audio and video application. De-
velopers hope the Mor}goose cable system
will soon replace conventional wire cables
carrying high-fidelity analog signals in runs of
up to 2.4 miles-
Why bother? According to a company vice
president, ft is the best way to connect both
audio and video components, "It is non-con-
ductive, has no impedance, and neither caus-
es nor attracts electrical noise." VP. of Devel-
opment of ASM Labs Armando Martinez fore-
sees market demand from twth amateur and
professional audio and video purists. The in-
tegrity of the original signal is uncompro-
mised." says Martinez, adding that this is the
first fiber optic system that is plug-compatible
with conventional equipment.
New kHz on the Block
The Federal Communications Commission
will hold frequency spectrum auctions this
fall, according to Chairman Reed HundT. The
frequencies heading for the auction block are
to be used to expand mobile communica-
tions, which Hundt says has the potential to
become one of the country's largest indus-
tries by the end of the canary, wittx at least
87 million customers.
Hundt also says he wants the FCC to pro^
mote competition in the communications m-
dustry, especially for cable TV, so rate reguia-
tfon can eventually be eltmlnated. TNX West-
link Report, No, 671, April 30, 1994,
Brain Cells
Energizer Power Systems and National
Semiconductor Corp. have developed a new
battery that monitors its own power consump-
tion and provides recharging communications
with the host equipment These "smart batter-
ies'' are expected to firs! appear in notetKx>k
computer applications.
The new batteries use nickel-metal-hydride
and nickel-cadmium rechargeable cells. The
intemal brains virtually prevent overcharging
and allow for useful 'lime-lefT or **% capacity
remaining" information to display on the host
device.
The announcement comes at a time when
portable electronics equipment use is sky-
rocketing. Duracell International and Intel
Corp. have also joined together to develop a
smart battery of their own. TNX Etectronic
Engineering Tunes, Issue 797, May 16, 1994.
FCC Cracks Whip
Fifty-nine Southern California hams are
under order from the Federal Communica-
tions Commission to retake their amateur ra-
dio license exams or face penalties* accord-
ing to a story in the Westlink Report. The
commission says all of the licensees in ques-
tion were passed at sessions conducted by
the ARRL-VEC In 1992 and 1993. Those vol-
unteer examiners are also facing government
scrutiny.
In a letter sent to those licensees, the FCC
fiatly accused the applicants of cheating. The
letter says, *" ... the irregularities on your ex-
amtnation papers indicate that you were ap-
parently given access to the exact (answer)
key used by the volunteer examiners.*
Those who were passed at the suspect
testing sessions have 60 days to retest.
Those who fail would face downgrade or loss
of license entirely. Refusing to retest could re-
sult in more severe penalties. So far, almost
three d03:©n VEs have been suspended tn
Southern California, in connection with test-
ing irregularities, under orders of the FCC.
TNX Westlink Report, No. 671, April 30,
1994.
What's Your $ign?
The callsign of your dreams awaits you,
and the price will be S7. Thafs the word from
the Federal Communications Commission.
On March 11, ttie FCC released its Notice of
Proposed Rule Making to implement the new
fee assessments for licensees who were au-
thorized by the 1993 US Budget Ad.
Item 69 of the NPRM notes fees for ama-
teur 'Vanity" callsigns. that are to take effect
whenever the commission's proposal is finally
approved. The current plan calls for a fee of
$70, or $7 per year for the 10-year license
term. TNX Westlink Report. No. 671, April 30,
1994.
Top Cop
According to Electronic Engineering Times,
a group of students at the Massachusetts In-
stitute of Technology recently showed they
were "complete engineers'* by arranging a
rather sophisticated end-of-semester prank.
The article quotes Bob Rivers, Human Re-
source Director at Bose Corp-^ saying the
MIT students displayed a number of desirable
qualities his company looks for when hiring
engineers: initiative, leadership, technical
knowledge, planning and organization, and
the ability to handle stress.
So, what did the students do? They some-
how constructed an exact replica of a cam-
pus police car — right down to a bag of Dunkin
Donuts— and lifted it to the dome of one of
MITs main buildings, all in complete secrecy.
As you can Imagine, the story was highly
photographable^ and made all the evening
newscasts in Boston. Rivers says these
young engineers also have another trait that
is very desirable in the workplace — a sense
of humor. TNX Electronic Engineering Times,
Issue 797, May 16, 1994.
TNX . ■ ■
. - . to all our contributors! You can reach
us by phone at (603) 924-0058. or by mail at
73 Magazine, 70 Route 202 North, Peterbor-
ough, NH 03458. Or you can reach us on
CompuServe ppn 7031 0.775 ©compu-
servexom: or at the 73 BBS at (603) 924-
9343 (300-2400 bps), 8 data bits, no parity,
one-stop bit. News Items that don't make It in-
to 73 are often put in our other montNy publi-
cation, Radio Fun. You can also send news
items by FAX at (603) 924-9327.
8 73 Amateur Radio Today • July, 1 994
With Packet Transmission
Salisfy your need for speed with the new PK-96 9600
baud packet controller finom AEA,
This high-performance machine comes standard with
1200 baud AFSK tone signaling, as well as 9600 baud
K9NG and G3RUH compatible direct frequency modu-
lation. The PK-96 makes an excellent ten'estiial or
satellite data controller. It can be used for high-speed
data Hnks to eliminate bottlenecks and in-
crease system capacity.
Big capability in a small package is what
you get from the PK-96- Under the hood, there is a 1 8K
baltery-backed MailDrop wliich is easily expandable to
lOOK. MailDrop allows you to automatically control
third-party traffic and receive and reverse-forward me?v-
Bring your system up to speed. Call AEA's Litera-
ture Request Line at (800) 432-8873 for more informa-
tion, or call us direct at (206) 774-5554.
Contact your favorite ham radio equip-
ment dealer for the best pricing.
CyOnnect
m
■»
Number 4 ofi your Feedback card
The Global Positioning System
An overview.
by Bill C[arke WA4BLC
The NAVSTAR Global Positioning Sys-
tem, generally called GPS. is a satellite
mdio posiiioning network providing ver\^ ac-
curate position, velocity, and time informa-
tion. Although GPS, developed by the U,S.
Department of Defense (DOD), can provide
three-dimensional position, velocity determi-
nation^ and pnecihiion time transfer, position
information is the most sought- Plans call for
GPS to be the DOD*s primary means of ra-
dionavigation. The system is capable of
serving an unlimited number of users any-
where on the ground, at sea, in the air, and in
near space.
Parts of GPS
GPS is comprised of three parts
(officially called segments):
space, control, and usen
The space segment is a constel-
lation of 24 satellites in semi -syn-
chronous orbits at an altitude of
20.200 km (10.900 miles).
The control segment consists of
a master control station located in
Colorado, and five monitor sta-
tions (MS) situated around the
world. As the central GPS pro-
cessing facility, the control seg-
ment is tasked with tracking, mon-
itoring, and managing the satellite
constellation.
The user segment consists of
the consumers of GPS, They may
be miliiary or civilian; however,
all must be properly equipped
with specially designed receiving
equipment, normally referred to as
a GPS receiver or receiver/proces-
sor, to make use of GPS.
How GPS Works
GPS position determination is
based on a concept called time of
arrival (TO A) ranging, which is
merely the signal's travel time
from transmission to reception.
A simple example of TOA
ranging: The distance from a
thunderstorm to your location can
be figured by counting the sec-
onds between a lightning flash
and die thunder report (the TOA
value). Multiply the TOA value
by 0.2 (the approximate speed of sound is
two tenths of a mile per second) to calculate
the range in miles.
The NAVSTAR satellites are broadcast
beacons transmitting L-band signals consist-
ing of pseudorandom noise (PRNi. The PRN
is predetermined strings of one and zero da-
ta bits, generated by an on-board clock that
also provides the exact transmit time of the
signals. GPS satellites transmit spread spec-
trum signals on iwo frequencies; LI =
1575.42 MHz and L2 = 1227.6 MHz. All ra-
dio transmissions are on the same frequen-
cies, with individual satellite tdentification
Photo A, The Trimble Navigaiton SCOLT GPS receiver (couriesy
ofTnmhie Navigation, 9020-11 Capitol of Texas Highvav North,
Suite 400^ Austin TX 78759: 800-959-9567 },
10 73 Amateur Radio Today * July. 1 994
made via unique individual code sequences.
When the GPS receiver begins tracking
the PRN sequences from four satellites (the
generally accepted minimum number re-
quired to proxide adequate accuracy), the re-
ceiver's data processor rakes oven
The processor samples the receiver's TOA
values, makes numerous calculations and
corrections that account for clock errors,
ionospheric signal delays, receiver noise, etc.
Much of the corrective mathematics used in
these calculations is variable from time to
time. The variables are provided to the GPS
recei%^er as parts of the satellite signal called
the navigation message (NAV
Msg),
The NAV-msg is superimposed
on the satellite signals and contains:
GPS system time of transmission, a
hand-over word (HOW), orbital po-
sition data, clock data, and almanac
data for the remaining satellites in
the constellation. The coefficients
for calculating UTC and the iono-
spheric delay are also included in
the NAV-Msg.
The GPS receiver computes the
position fix in coordinate terms,
consisting of latitude, longitude,
and altitude.
Note: A GPS position fix refers
to the electrical phase center of the
receiver's antenna, as the antenna is
die actual point of signal reception.
The normal tracking sequence
begins with the receiver determin-
ing which satellites are visible for
tracking, via user-entered predic-
tions or stored satellite almanac in-
formation from previous NAV-Msg
data. If there is no almanac infor-
mation. a search of the sky must be
made to locate and lock onto a
satellite. The receiver can then read
the NAV-msg and get current al-
manac information about the other
constellation satellites. This may
sound rather complicated; how^ever,
the user can relax as the entire pro-
cess is done automatically by the
rece i ve r/proce ssor.
[f's interesting to note that the
typical satellite received signal lev-
el is below the earth's natural radio
MFJ
Wcnre Ground Plane
For an incredible $19,95, you get a 300 watt 5/8 wave ground plane 2 Meter base antenna.
Other 5/8 wave ground plantes can V work any better - no matter how much the cost.
\
DvfifSimill 44/440 MHz
Ground Plono
MFM754 A/^uif
*24"
Dual band
ground plane
antenna for 2
Meters and 440
MHz gives you
extra long range
MFJ- 1750 For an incredibly low $19.95, you get
M A 95 ^ complete 2 Meter 300 watt PEP 5/8
^ ^^ wave ground plane home station antenna.
It gives you the maximum possible gain
of any single element antenna.
Competitive 5/8 wave ground planes can't
wofk any bener — ao matter how much they cost.
You gel . . . shunt fed matching that bl^ds off
unwanted static and gives you lowest possible
5/8 Wave 2 Meter Mobile Antenna
MFJ-t728/B
•24"
I
For maximum range while mobile, use
MFJ's Maximum Gmrf 5/8 Wave 2 Meter
Mobile Antenna. You'll get the maximum
possible gain of any single element mobile antenna!
Competitiir'e 5/8 wave mobile antennas can't work any
t>etter — no matter how much more they cost.
You get low SWR so your rig can safely deliver
maximum power into your antenna. It's rated at 300 watts
PEP so you can use any mobile rig plus a mobile amplifier
You get a heavy-duty magnet mount that holds your antenna tight at
i.
on 440 MHz with a high gain hdfwave tjighway speeds ami a hl^k magnet base ihaiTl look good for ycais
over quarter wave radiator. On 2
Meters you get solid quarter wave
performance. Mounts on 1 to Vh inch
mast with single U-boll. Easy-to-tune.
1/4 Wove Ground Piano
MFJ- 1740
The MFJ- 1740
brings up 2 Meter
repeaters as well
as any Vj wave
ground plane made!
You get easy tuning, low loss
ceramic antenna insulator and strong
lightweight aluminum constniction
Yon get a stainless steel radiator that'll endure years of harsh mobile
use and 1 2 feet of coax cable.
You get MFJ's one year No Matter Whai^ uncondifional guarantee.
Order MFJ- 1 728 with standard PL- 25 9 coax connector or
MFJ-1728B that also includes a BNC adapter for your handheld
Sluclreif 5/8 Wav« for 2 Meters
gives twice the omni-directional gain of a single ^/8 wave
MFJ 1 764 ^^i 's stacked 5/8 wave radiators give you
*^ - ^^ more than fwice the omni-directional gain of
34 a single 5/8 wave radiator!
Wide 1 0 MHz 2; 1 SWR bandwidth , . . excellent fcrrite
choke balun feedline decoupling . . . shunt choke for bleeding
off unwanted static . . . suong lightweight aluminum.
Fully assembled — simply attach radiators — no tuning
n
Single U-bolt mounting for I to Vh ^"^^^^^^^ vertically for FM/Packet or horizontaUy
1.TM
inch masL Cutting chart included for
220^440 MHz. Made in USA.
MFJ PMk«t Roll-Up
? Meter halfwave J^pole antenna
MFJ- 1730
RoU up this
laifwave 2M
*pole antenna
ind stick it in
'our pocket! It's
he perfect gaj>i antenna for traveling.
Get home station performance on
^e go. Just hang your MFJ Pocket
*oU'Up^ in the clear and ptug the BNC
on nee tor into your handhdiL
IVs omni-directional and has
ignificant gain over a 1/4 wave. It
oesn'l need a cumbersome ground
lane so it's convenient for indoors and
'orks great with handheld^.
tmm Band fiexible Docks
f 44/440 MHz flexible ducks far HTs
A. High Gain FkxiDuck",
fFJ-1717, $19,95. Enjoy
spendable QSOs when other
ibber ducks give you noise,
igh gain V2 wave on 440 MHz
ill si^e V4 wave on 2M. Won't
b you -- bends, twists, flexes
ith you, 15^/4 inches. _
B. FlexiDuck^, MFJ-Hlfi, A. B,
16,95. Similar to MFJ- 17 17. Full '/<
ave on 440 MHz, efficient loaded V-i
ave on 2 Meters, 8^4 inches.
Mitfrf]f Dvck^ for HTs
Add this short, A% MFJ- 1718
zh ShonyDitcIrio yoni *12*'
il h:indheld for a Q-^5 __
Tnal! Impedance matched for maximum
in. High-Q helical w^ound radiator
for SSB. Installs with single U-bott on 1 to 1 '/s inch mast
or tower leg. 1 '/^ lbs., two 47 inch radiators, 23 inch boom. Made In USA.
Also works as excellent 6 Meter fuU halfwave ceaierfed antenna.
MFJ-1766, $89-95, gives yo\i four iime^ the gain of single 5/8 wave.
Includes 2 MFJ- 1764, phasing cables. Doubles gain on 6 Meters,
MFJ- 1765, $29.95, phasing cables for 2 MFJ- 1764s, o![ilt 2M ant.
MFJ dual band 144/440 MHz Yagi
5 elements on 440 MHz, - - 4 elements on 2 Meters . . -$49.95
Get two Yagis for The price of MFJ4 76S
one . , . enjoy two Yagis in the ^49*^
space of one with single coax feed! Afeii
MFJ's exchmm dual band balanced -^
feed with fVmrfC/ic^Jfce"' decoupling prevents
pattern skewing and gives you low SWR.
The MFJ- 1768 is bitsed on ihe Naiiomii
Bureau of Standards design that's optimized for maximum lorward gam
with high front-lo-back ratio and a clean symmetrical pattern,
Mounts vertically for FM/Packet or horizontally for SSB with
single included U-bolt on 1 to I 'A inch mast or tower leg:
■ Nrtigh strength 6061 -T6 aluminum 5 foot, t % inch diameter boom. 2
pounds. Elements are electrically isoiated from boom. Made in USA.
Partabim Z element Yqqi fer 2
^SoM^ You can set up or take down MFJ's
39 portable 3 elements 2 Meter Yagi in
seconds! Elements simply screw into the boom.
You can take it with you wherever you go and
have the ""oomph'* and directivity of a beam.
It's easy to store and sturdy enough to use as
your home station antenna
Mounts vertically for FM/packet or horizontally for SSB. Center
or e/j^ mounts with single U-boli. Great for packct^ackeiCluster™.
It's compact 2^M foot boom gives you a calculated gain within 1
dB of a four element Yagi with a boom nearly twice as long.
Extra thick elemenLs maintain high gain and directivity over entire
2 Meter band. MFJ's FerriteChoke"^ decouples feedline.
Elements and boom are made from strong lightweight atuminum
and protected by MFJ's Permanent Molecular Banding Technology
Weighs just 2 pounds. Boom is 30^2 inches. Made in USA.
CIRCLE 96 ON READER SERVICE CABO
SWR . . . Strong lightweight aluminum
construction that's protected by MFJ's Permanent
Molecular Bonding Technology^ . , . low loss
ceratnic antenna insulator for maximum radiated
power , . . MFJ's RapidTune'^ radiator for quick
acctirate tuning . . . super easy installation to any
1 lo 1 Vi inch mast with single U-bok (included)
. . . and it's Made in USA.
MFJ^17S2, $19.95, for 220 MHz band
MPJ DvalBmd Mobil*
Mobile Antenna for 144/440 MHz
MFJ-1724B
Opo^teboth 144
tmd 440 MHz with a
single magnet mount
mobile antenna!
You get excellent
eain on 440 MHz with a Vi wave over
74 wave radiator and 2, full '/4 wave on 2
Meiers for noisc-ftee, long range QSOs.
Its stainless steel radiator is only 19
inches tall so you can park in your
garage without knocking it over.
An extra powerful magnet holds it
steady - even at highway speeds*
Use it with mobiles and handhcldsf
You get 15 feet of coax widi a
standard PL-259 coax connector and a
free BNC adapter for your handheld,
lt*s protected by MFJ's famous one
year No Matter What" guarantee,
HT Rang* Eirtondon
Telescoping antennas for handheids
A. Lang Ranger^ 2 Meter Halfwave,
MFJ47H $16,95. For lually long range
this MFJ endfed halfwaw is hard To beat
li outpeiforms a V* wave on a handheld
because the -h wave needs a grrwrnd plane.
The MFJ halfwave doesn't. ll*s shorter,
lighter, has more gain and places less
stie;ss on your antenna
connector than a V» wave
antenna. When ct>l lapsed, it
perfcHins like a rubber duck. 40*
extendedl lOV/ cotlMJsed.
B, Dwa/ Bonder^ for 2
Meiers and 440 MHz,
MFJ*1712, $14.95. Got a new
dual band handheld or sepiirate ^
units? One antenna his all. It's a
'/j wave for 2 Meters and a % wave with
gain for 440 MHz. Tk" collapsed, 19^
extended,
a Pocket Linear" Y* Wave, 2
Meiers, MFJ-1 710, $9.95. Carry this
pen size antenna in your pocket like a
ballpoint pen. When you re using your
rubber duck, on the fringe and noisy,
put on the Pocket Linear^'*, extend it to
24 ¥2" and carry on your QSO. Has
pocket clip, 5V4" collapsed.
1 44/440 MHz Duplex«r
LpCts you use MFJ -9 \ 6
dual bynd 144/440 $29^'
MHz antenna with
separate transceivens or sep-
arate 144/440 MH^ antennas
^.
i
t
P
1
M
tM
wi th dual band transcei vc r, ' r f '
Nearest Dealer/Orders: 800-647-1800
Technical Help: 800-647-TECH (8324)
• 1 year tjncondrt/onaf guarantee • 30 day money back
guarantee (less s/h) on orders from MFJ • Fjnee catalog
MFJ ENTERPRISES, INC.
Box 494, Miss. Statc» MS 39762
(601) 323-5869; M:30CSXMoiFFii
FAX: (601) 323^551; Add s/h
MFJ - . - making quality affordable
Ftkd mi tpcaSiaiaom mbjp^i ludiMft C 199* MFJ Emcrpnsrs, Inc.
noise leveL After detection, the satellite's
sigmil is multiplied hy use of receiver-pre-
dicted PRN codes and with ihc received sig-
nal collapsed into the originiil carrier fre-
quency band, concenirated. anti brought well
above ihe natural noise leveL
Simpiv CmnplesL
The average GPS portable receiver some-
what resenibles a VHP handheld transceiv-
er in size and weight. Functionally, you will
find the GPS receiver simpler lo opemie, al-
though somewhat similar in flavor. Buttons
operate selection menus and functions are
selected from those menus. Ret^tring to the
Trimble Navigation SCOUT GPS Receiver
in Photo A. ntjle there are only eight buttons
for control. By using the builons and the
scrolled menus appearing on the LCD dis-
play, the exact location can be determined,
routes may be programmed, locations mem-
ori/ed, distance from previous or input loca-
tions computed, and speed calculat-
ed.
(rarely ai^ complexities a user concern as
most GPS receivers are designed for ease of
operation). The types of receivers consist of:
Sequencing — ^This ty^pe tnakes use of one
or two hardware (RF) channels by simple
stepping from one seSected satellite to anoth-
er on a timed basis. Sequencing receivers
use simple circuitiy* and have low produc-
tion costs and low power consumption. They
are adequate for most piiqioses except high-
speed navigation.
Continuous tracking — These have a mini-
mum of four hardware (RF) channels and
track four or more satellite's ^imuhaneously.
They are less affected by speed ttian the se-
quencing receiver.
Muhlplex (MUX}— ^\i\i this type, a sin-
gle hardware (RF) channel is switched at a
fast rate between satellites being tracked.
Switching is typically 50 times a second.
The multiplex receiver is based on time
sharing and requires only a single code gen-
GPS Accuracy
GPS was designed to suppon a
broad spectrum of users with differ-
ing requirements of accuracy. Basi-
cally, there are two categories of GPS ._^_
accuracy service:
The PPS, precise positioning service,
which is extremelv accurate and available
for use only to those authorized, and the
SFS, standard positioning service, a less ac-
curate positioning service which is available
to all GPS users. PPS and SPS are function-
ally identical: however, access to the PPS is
limited by encryption techniques.
PPS» primarily intended for mililary pur-
poses, typically provides accuracy of 22 me-
ters horizontally. 27.7 meters vertically, and
time within 90 nanoseconds.
SPS, used for civilian purposes, is speci-
fied to provide 100 meter horizontal, 300
meter vertical, and 1 70 nanosecond time ac-
curacy. The horizontal specification includes
peacetime degradation of selective availabil-
ity (lI means of tinkering with the system to
make it less accurate in the name of national
security). For the SPS user, selective avail-
ability t^ the dominant SPS accuracy error
source.
In practice, the spec ificut ions are easOy
attained, with mucli greater accuracy the
rule and not the exception,
GPS Receivers
Although the technology of GPS is fasci^
nating, it is not feasible for the average ham
to construct a GPS receiver. Not that some
hams aren't capable of the job — it just isn't
feasible (read: worthwhile). No more so than
building a 2 meter HT with all the current
bells and whistles would be.
There arc several types of baste GPS re-
ceivers, vaxy ing in complexity, tracking ca-
pabilities, speed of information update, and
planned use. Unfortunately, corporate mar-
ket] ns has clouded the identitv of some re-
ceiver types and operational complexities
^Wow that you have been boggled
by the high-tech world of GPS ^ you
might ask^ ^Whafs in it for me?^'*
erator and carrier synthesizer for tracking.
Digital — This type uses analog-to-<iigital
conversion techniques with a single receiver
IF for signal amplification. Signal process-
ing is accomplished digitally. This type of
receiver can be visualized as a single chan-
nel radio iiecei\ er with five digital chajinels,
each monitoring an individual satellite.
Hams and GPS
Now that you have been boggled by the
high-tech world of GPS. you might ask,
"What's in it for mc?"
Using GPS, a ham can display his exact
location and figure distances to other loca-
tions. Other locations might include previ-
ously *meniori zed points (locations electroni-
cally in the receiver) or latitude and longi*
tude points entered manually.
The exact location of VHF/UHF repeaters
can be determined for ease of mapping
planned coverage and determination of po-
tential interference with existing repeaters.
As the GPS is a three-dimensional system,
altitude can also be displayed.
Distance between known points can easily
t)e displayed. Just push a couple of buttons
and indicate the points to be referenced*
Again 1. for repealer usage, coverage could be
determined by following a line of signal
strength and niurking locations on a map.
Distance calculations can be very important
for mountatntop VHF/UHF operations.
The Maidenhead grid locator system (grid
squares) is programmed into the SCOUT
GPS receiver and indicates grid squares to
about 75- foot accuracy. The display consists
of the basic field, square, subsquare, and the
TGL (Trimble Grid Localor); CM 87 XI 42
LF, which corresponds to latitude/longitude
of 37 degrees 20 minutes 33-0 seconds
North/122 degrees 2 minutes 46.8 seconds
West.
Many hams find themselves involved
with search and rescue duties, whether
through the Civil Air Patrol or other public
service agencies. Using GPS for precise po-
sitioning, coverage of search areas is very
accurate and efficient, leaving no area over-
lapped or uncovered. GPS receiver readings
can be directly applied to maps, and map-
ploned positions quickly located.
WTiere ts GPS Going?
Although initially designed for militaiy
usage* the civilian world has discovered
GPS. No doubi the system's user simplicity,
accuracy, and reliability factors have accel-
erated its acceptance. It is safe to say that
GPS wilL at some point in the future, direct-
ly impact nearly everyone.
The military uses OPS for aviation, ma-
rine, and lami navigation. Examples
include: aircraft instrument liindings
and carrier landings, rendezvous
such as irinighi refueling, improved
bombing accuracy and ballistic
weapon delivery (smart bombs),
close air support, reconnaissance
^_^_ and target location, enhanced site
surveying and field artillery place-
ment. Insertion and extraction missions may
be carried out with extreme accuracy (with
safe and timely deployment and evacuation
of troops)^ including niedi-vac.
GPS was used during Operation Desert
Storm for land navigatitin in the desert areas
where maps of the deserts were virtually
non-existent and desen physical/geographi-
ca! reference points wens scarce.
Marine navigation becomes very simple
using GPS and harbor navigation accuracy
will be greatly improved over current meth-
ods* Waterway and other mapping becomes
as simple as pushing a few mcmor\' buttons
while over-nying or otherwise crossing an
area. Later memory examination allows
maps to be drawn.
For civilian purposes, the applications for
GPS appear to be without limit. More and
more uses are being found all tlie time, in-
cluding:
Replacement of the various radio-based
aviation and marine navigation systems.
Creation of a differential GPS (0GPS)
system to increase the positioning accuracy
to about 10 meters (39 ft), DCPS only re-
quires that a local positioning signal be
added to the mix of calculations made b} the
GPS receiver.
An ambitious projected application for
GPS is Intelligent Vehicle Highway System
(IVHS) technology. IVHS is planned for
limited use in the year 2000. Nearly a billion
dollars has already been spent or allocated
for its development and implementation.
IVHS encompasses automated highways and
computer-aided vehicle guidance.
Rail systems and trucking agencies are us-
ing GPS as the basis for traffic management
and scheduling.
12 73 Amateur Radio Today • July. 1 994
Simply A Superior
1.3 GHz Spectrum Analyzer
UMENTS MODEL SAUO;JA
CHSPtfrSibDH
mm
tun 1i2>i
rrrrn
oc i»w +06 £W
1-1300 MHz In One Sweep $1,795.
MADE IN USA -lOKHz Resolution Band Width -7 Digit Center Frequency Display
MARINE, TWO-WAY, HAM, AM FM SW BROADCAST RADfO - CATV, SATELLITE. SYS,, SURVEILLANCE
TUNE DUPLEXERS, AMPS, FILTERS, SECURITY TRANS, & RECEIVERS - EMI, RFI, FCC, TESTING
EXCLUSIVE DISPERSION ZOOM
ITC SA Series exclusive Dispersion
Zoom lets you zoom in on any Center
Frequency signal, (rem any one of
five calibrated Disperston positions.
Preset at >140 MHz, 50MHz. lOMHz
IMH2 and zero MHz per division. The
SAtSOOA displays greator then 1300
MHz on the screen at one time yet
allows Instant zoom to any Dispersion
Scan Width as low as zero MHz per div.
Allowing for total control over all
Dispersion Scan Widths settings.
80 dB ON SCREEN
130 da total Dynamic range 110 dBm
Sensitivity. At Narrow and Wide Band
Width settings. Performance you would
expect only from a SI 0,000 Analyzer.
DKTRmUTED BY:
ULTIMATE LOIV COST ANALYZER
ITC Spectrum Analyzers are the beet
performance to price ratio Analyzers on
the market today. No other low cost
Analyzer comes close to the Superior
performance and qualfty of an ITC
Analyzer Total flexibility and ease
of operation, SA1300A gives you full
control over the Resolution Band Width
and Freq. Span widths. Plus Vertical
Position, Baseline Clipper, Sweep
Speed, Video Filter, 4 input Attenuator
settings, 1 0 Frequency Select settings,
MODEL SA1800B 1800 MHz
Covers 1-1300 MHz and 850-1850 MHz
in one sweep. Ideal for Satellite service.
The SA1800B has the same general
specffications as the model SA1300A.
INTRODUCTORY OFFER
SA1300A &OPT.S 1,3,6
ONLY $1795.00 nc^i
SA1800B & OPT.s 1,3,6
ONLY $2195.00 ooie i
S19S5.00 Opt, 1,6 ONLY
SA13(KIA 51595,00
SAISOOB SI 895.00
OPT.l SOMHz MARKER S200.00
OPT, 3 -H- SKHi Re* RW S350.00
OFT. £ 1000 Ml-k Tracking Generator S250.00
OPT. 6 7 Digit Center Frequency Diipliy $300.00
N0t^ 1: Introductory Price for limited time only.
TAKE ADVAIVTACIE
CALL 1-800-566-1818
To: Order - For ln[fQrmatk>n & Speckl Errtro. Offer
TtiBf MQVISA, A£,C%«di,COD,PO(OAC),LCtTnftiiyr
All 1 A]\ I Alllli INSTRUMENTS CORP,
3276 KITCHEN DR RO, BOX 2152 CARSON CITY NV» 89702
1-800-566-1818 702-885-0234 FAX 702^85-7600
PRICES & SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE OR OBUGATION* RO.E CARSON CITy NV. NV. RESIDENTS ADD SALES TAX.
CIRCLE 149 ON READER SERVICE CAHD
m
In the realm oF public fiiireiy, GPS will as-
sist in resource managemeni, allowing dis-
patchers to accurately determine where po-
lice cars, fire trucks, and rescue equipment
arc located at any given lime. Police dis-
patchers will know the exact position of ev-
ery car available or in use and can send a
unit to assist whenever necessary, possibly
saving an ofUcer's life. Fire departments and
rescue squads can use computer-based maps
and information giving locations of fire hy-
drants, water .supplies* and directions of
travel Using differential GPS» it is possible
lo locate individual rircfighters inside burn-
ing structures.
During natural disasters such as earth-
quakes or floods it will be easy lo locate un-
derground utilily lines, boundary' areas, and
limiis of ulTecied areas.
GPS allows land survey and mapping lo
accuracies of two inches or less. Special
techniques and equipment are used for accu-
racies of this level
The locations given by a GPS receiver
can be applied to maps, preventing hikers
from becoming lost. Further, in the event of
an emergency, hikers can transmit (via
phone or radio) their exact locations.
Important GPS Uses
An expedition scaled the tallest mountain
in Nonh America. Mt. McKinlev, in June
1989 to determine its exact height by use of
GPS. The exact height was determined to be
20306 feet, which is 14 feel below the 1954
trigonometric measurement (anyone for
placing a repeater up there?). Other moun-
tains measured using GPS include:
Ml Fuji, tallest mountain in Japan, at
12,382 feet.
Mt. Logan, Canada's tallest peak, at
19346 feet
Mt. Evenestt tallest in the world, at 29,022
ft.
GPS was used to accurately place ihc po*
sition of the Titanic, During the Great 1993
Flood of the upper Mississippi River Valley.
GPS was used extensively to monitor areas
covered with waten Similar advantage of the
system was made during the Christmas Eu-
ropean Floods of 1993.
GPS — ihc Global Positioning System — is
in your future, B
For an in-depth study of GPS, see she au-
thor's latest bo€7k. Aviator's Guide to GPS,
published by TAB-McGraw Hill: telephone:
(800) 23S U28.
m COLOR
SLOW SCAN TV
for the Sound Blaster!
Now send and rmc^vm Shnr
Scan TV mtm fi^ut Souivi
in FUU COLOR! !t
SLOwsejmii
N<»w copy $low Scan W (in
B&W), wilh your Gound Blasler
compatible ftound cnrE}. Re-s.eiid
pictures that you wcat^fet Sa^t
as.PCXofVOC files.
irsFUjyitt
ONLV S40.Qfl
AUDIO AHAIVZER
Anatyze mo«« iudto »»giiAU that
you hcAr tuch at SSTV, RTTY,
f^ir^t. Had Packet udio_ Copy
Eve or froifi ■ .VOC fite.
fte|llin» FCp VQA fiiO 1 440 - W^ CtiN?rt, «md SCHtnd BlAster cotTVp. tMt
Sll4f»p«ti$ fi ■ OvttttbM^ lid - llUhOii tvuMon\% Mid 6i^% lAK
Harlan TechnoEogleB 813-39M683
5931 Alma Dr. - Rockford, Illinois 61108
CABLE X-PERTS, INC.
COAJt
=:^XI6LE $9t3 (WECT BUFUL JACKET ^
loofL/uf soorr
«4G f ' ^U MIL ^SPBC OlAeCT Sk^tk^ JMXEt .
.€2M
^34«
-57*
RG WVa BX mj( Of ait UV JAQET.
RQ-ieBA>-lillL^>e&
■(+»TliHliH^
nOTCm CABLE
C4E«0 STD DUtir 2t^t-9l^ UV JACKET
C4{»a Hvy OJTY &i«HMa i/v jmsket
IBGA*C QRAY JACKET - .-.
iBGfl7/CQflA¥ JACKET . „-,
AKTENNAWme
14GA 16a STfi SUPEfl-KLEK UNINSULAtED
l^CiA r.'2£ H.O DC UNfMSULATED
UGA SOUD ■COPI'LHWEUD- UNNSULAtED
taoA ie 3TR FiExraiE ac unh^ulateo .
BALUNS
WaiMJ J 1 ELM t S-aOMHrCWWr™,^
ORKUMALOanVKlT
TfWPBI&aOWm
Cen^i KSuLATcn .
l"H"l l«"l«"
rlihl iiHaninqr
aaiaananmn^h
.IBffl
,12/rt
.07,Tt
,iim
-^ t^ST
3at
MM
.tj/n
.ICkft
PRICE
_ K£fia«a
13 GA F^Eiaxa9ft-46 TT^ •.
!12nf> ""lilt
tSaClt*'U«lOEftLJrt"*Ba*KJLtJC>V _
WORE. iTil0 BTOCKED JMCLUEMMG CCM4NECTORS £ AMTEJUMAS
CABLE A WIRE CtfT TO VOUR SPECIFIC LENGTH
ORDERS ONLY: 800-828-3340
TECH INFO: 708-506-1886
Buffalo Grove, IL 60039-1797
far Camfii&te Ut^$r^turf MmU BASB
VOX CONTROLLER
SECOND GENERATION
nexl geticration VOX coiilroller wiUi odj vox
sensitivity, timers and CWE>. Operate VOX
Willi no intenial coniieclions to your railios
or COR for more demajidiiig systems.
BC~2I w/ CWID & enclosure $89.95
Add IXrMF mit coiitrfvl, putcli and oulpiUs lo
coniml uUicr cquipinciU Lo Ihc l)C-2].
BC-2R adds rmt Ctrl and patch $79,95
&TMF decoder Bo«rdf for every need
BTJ>8C has 8 latched, rmt loll-restrictinn,
LilZ, IC sockets & more „„...„ $99 95
BTD-8M mommurv^ ouiiHrti,, ,.,„.._,„ $79.95
B'n3-8A . $69 95 Orig BC.L...$34.95
Box Products, Inc Orden 800*854-2426
P.O, Box 57 Info 90 1 -968-54 1 6
Lexington, ITsf 38351 add $4JK) S -fe li
CIRCLE 187 ON F1EADER SERVICE CARD
CIRCLE 137 ON HEADER SERVICE CARD
SCARED OF THE CODE?
rrs A SMAP wmi the el£0aktly simple
MORSE TUTOR ADVANCED EDITION FOR
BEGINNERS TO EXPERTS— AND BEVOHD
Morse Codv teaching software from G<jTE ^ th«
most popular In ttw y^orh^— and ror good reason.
Vou'll leam quickest with the most modem teaching
methods—Including FarnGworlh or standard codst
on-scr&en flaslicards, random chnracterft^ words and
billions of con v«r«a(ions guaranteed to contain every
reiqujred ehiracter every time- — ^n 1 2 easy lessons.
Sneah through txi^her^ome plateiuft in one tenth of
a won] per minute siep^. Or, create your own dfifle
end play thefn, print them and save them tq 6i9k*
Import, analyui and convert texl 1q code for ad<liUofV
aldrtlle.
Qm the B<7ftware the ARRL 3«ils and uaes to create
their practice and test tapes. Mof«4 Tutor Ac^anead
Edition i« approved for VE exama at all levels, Mort*'
Tutor is great — Morse Tutor Advanced Edition is even
better— and it's in user selectable color. Order youri
today.
For all MS-DOS computers (Including laptops).
AvBileble at dealers, thru QSfor T^or send S29.95
+ S3 S&H (CA residents add 7.75% tax ) to:
GGTE, P.O. Box 3405, Dept. MS,
KeWpOft SeMli, CA 92699
Specify Si'* or 3 ^^ Inch di«it
(price Includes 1 year of free upgrades)
7S
CIRCLE 1 93 ON RCAIIQI SCRVICC aU»
Slow Scan TV
doesn't h^ve to be expensive anymore]
Every- dai< inore turns are erttiafKifi^ ihsa ccmmufitcaUan b>- yiing
im^^s. ii>in ihe fun and. ^£. wf\ai yiSM^^t bixn missingr
QuaJ]iy Coldr SSTV 1 1 nxy md aftofdibte wiih t^mtm TV. 5239.9^
Requires IBM Pii^'iiPiuiMl^ilik, 'BttfrorbcUer CPU, L MCfti^Uflf mEciiDcv. calnr' V-ClA
Jispln^^ M!^POH <;hii|;ipili(|. 32 la U.S.A. wndrufiiKktU^ far olhfiu Wnle ur hII tor
Abiolutt Valiie Systems
1 1 5 Scfidman Sl jV 7
Chelmsrord, MA 0 1 82^ 1 82 J
(501) 256 6907
|ohnl#wodd,atlxom
HIGH POWER RF SWITCHED PREAHPS
Model 146
S165
Model 1460S
$165
Model 440
$t79
iiodtr 146 f &0W 2 Meters 19dD Gain J5<tb Nf
Model 1460S 160W 2 Meters 19db Gam .7Sdb Nf
Model 440 70cm 100W 1 6db Gain JSdb Nf
All preamps have helical tillers to prevent out of
bafid inlermodulation in the receiver. Mode! 146
covers the entire 2 meter band. Model U60S is
of very narrow bandwidlh and would be suitably
for SSB. PackeU or SateNite, Model 440 is factory
tunable from 430-440 MHz or 440-450 MHz per
customer request. All models are powered with
13 to 20 VDC and are mounted at the antenna.
AMFIRE, INC.
10240 NATHAN LANE
MAPLE GROVE, MINN 55369 612-425-7709
ORDLE 3S1 QH READEH SERVICE CARD
1 4 73 Ama tear Radio Today • July, 1 994
«
Gtobaf positioning system (GPS) receivers
display latitude and longitude on ttieir LCD or
CRT screans. They also show SOG (speed
over ground), COG (course over ground),
speed, and distance to pre-memorized event
Of waypoint markers.
The latitude and lor^grtude numbers would
lead to position accuracies of approxin:iately
10 feet, bul the last significant number regu-
lariy charges. Why the change? This rs be^
cause your positron is purposely being diluted
by ttie Department of Defense GPS satelfite
system to a 100- meter radius of a circle. It*s
called "selective a variability/ and purposely
denies pinpoint accuracy to civilian users in
order to provide a safeguard to national de-
fense.
This selective availability— also called sig-
nal dithering — can be all but eliminated by
subscnbing to commerdal or government dif-
ferential GPS signals. The differential signafs
correct the selective avai! ability error factor
from somewhere within a 300-foot circle
down to within a 5-foot circfe 95 percent of
the time* For the ultimate in accuracy, you
would subscribe to your local FM slatron sub-
carrier access {SCA) driferential GPS signals
along wttb a little black box that hooks into a
differentia I -ready GPS receiver.
For mariners, the differential correction sig-
nals come in tree of charge from the United
States Coast Guard. These are received on
the 300 kHz marine radio beacon band, and a
DBR that simply plugs into most portable or
fixed GPS sets tor boating position accuracy
of approximately 1Q feet. The U.S. Coast
Guard differential system covers all of the
East Coast, all of the GuFf Coast, and stations
are going in right now for thre West Coast and
Alaska ^ Canada also participates in the differ-
ential GPS program Hams living within 100
miJes of a participating U.S. Coast Guard
beacon station should be able to pufi in these
low- frequency signals, modulated MSK (mini*
mum shftt keying), with the right commercial
equipment. No monthly user fee!
But latitude and longitude coordinates may
not mean much to ham radio operators using
GPS equipment for county -line calculations,
biking topo maps, or ihe common street at-
lases which rarety list latitude and longitude.
Hams need something etse, and they now
have it!
One expensive solution Is to tie a laptop
computer into a GPS receiver with differentia]
capabilities, and buy mapping software or
maps on CD-ROM, If you have a computer,
this is one option for you to consider.
!f you need a portable mapping device.
Sony is just coming out with their new Pyxis
Model lPS-760 thai uses micro C-Map car-
tridges, that are ordered directly from the sup-
plier for approximately $129, covering several
hundred square miles of area. These coukj
be cruising charts, topo charts^ street maps,
or even the popular airplane charts.
Panasonic and Lowrance Electronics are
also ptannirg on hand-held GPS chart de-
vices which will give you the cartographic da-
ta on a chart-like screen ttiat covers a select-
ed area of interest.
Tnmble Navigation (Sunnyvale, California:
1/800/827-8000) combines the power of
GPS Maps and Charts
by Gordon West WB6N0A
Thomas Bros. Maps and their hand-held
Scout GPS, which converts the incoming sig-
nals to grid references in the map book. Or,
for the VHF/UHF operator, the unit can actu-
ally read out which grid square you are in with
no map book required!
"Oirr Scout offers a choice of nine coordi-
nate displays: latitude and fongityde in sec-
onds or minutes; universal transverse Merca-
tor map projection; ordinance survey of Great
Britain; Trimbte Attas from Thomas Bros.
Maps; Maidenhead grid iocator system, in-
cluding sub-square accuracy; TrimWe grid lo-
cator— extension of Maidenhead for addition-
al accuracy."
*With any of these readouts, our GPS
equipment is ideal for the ham operator/'
comments Jim Osdaie K6EUD, a local ham
operator who teaches GPS navigation
(714/779-5003).
Many ham operators have discovered a
unique fixed-mounl LCD screen GPS receiver
from Lowrance, the Global Map 1000, as hav-
ing the most buift-in cartography for the buck.
Boat GPS sets usually incJude an oullfne of
the United Stales as part of the basic cartog-
raphy built into ttie unit- For a close took at a
locaf tiarbor. you would purchase $150 C-
Map or Navionics cartridges, plug them into
the GPS mapping unit, and presto, a vague
outline of the U.S. wiil come into locaf harbor
detail, C'Map is also working with Navionrcs
to soon supply cartridges for selected lakes
and rtvers to cover those hoi fishing spots.
But when Lowrance asked tor a "canned"
map of the United States to be burned into
their firmware, little did they know what was
going to be supplied — the United States with
all major freeways and expressways built into
the system without the need for any addition-
al iocal mahne chart cartridges.
1 don't go anywhere without my Lowrance
GPS set in a rentaf car" comments Bill Alber
WA6CAX, a traveling marketing consultant
who has put away the map books for bis
new electronic readout, 'When I am talking
to someone who I will visit in a few weeks,
I teli them I must have their latitude and longi-
tude along with their office address. I enter
this into the GPS charting device ahead of my
trip, and presto. \ see exactly where Tm going
as I'm pulling out of the parking lot." adds
Alber. "When it goes beep on arrival. I am
usually within 100 feet of the front door,"
smiles Afber.
State outlines arrd many county (ines are
also included in the canned cartography.
Same thing with nvers, too. And if you turn on
your trail plotler, you can capture exactly
where you have been, and see exactly the
route you took. To demonstrate the accuracy
of the plotter, see the 73 logo in Photo B.
All marine-lype GPS sets are priced at
tfie bottom end of Ihe long list of equipment
designed for commercial surveyors. A survey
set might run $3,000, bul you can buy a
marine Garmln GPS -50 for under $400! The
inexpensive marine sets also output NMEA
0183 data, and this ties into those S6O0 LCD
chart display systems. Those marine sets
ateo tie in nicely with APRS — automatic pack-
et reporting system. This turns your GPS
set into a position enunciator that squawks
your location on packet! Not only can you
see where you are, but other APRS systems
can actually see where you're going on their
system.
During a recent trip throughout the United
States, ] found that the GPS antenna/receiver
unit worked nicely in the back window of
rental cars. Only now and then did the recep-
tion drop out when I was in between tali build-
ings in Miami and Los Angeles.
Manne GPS prices wont dip much beiow
$400, so check out what is available down at
the marine stores, and tune into 1575 MHz
and get set for hand-held and mobile position
finding.
Photo e. The trait plotter feature aliows you to display exactly wherB you've beer}— in this case, on the
73 traiti
73 Amateur Radio Todsy - Jufy, 1 994 15
IHi
Number 5 on your
kcard
World's Smallest 10 GHz
ATV Transmitter
Build one on a PCB using only a few componentsi
by Angel Vilaseca HB9SLV and Jean-Pierre Morel HB9RKR
/
The availabiliiy of cheap surplus GaAs-
FETs lately has made a lot of microwave
experimenting possible for amateurs. This
article deiicribcs a new kind ol' amateur 10
GHz low-power transmiiicr using a surplus
GaAsFET, mouitled on a tiny piece of
Teflon/glass PCB. Wideband FM modula-
tion is possible for ATV operation.
As microwave-oriented amaieurs, we (the
author*^} began experimenting back in the
*80s, using Gunn diodes in waveguide as-
semblies. These, provided ihey were home-
by ill, using cheap surplus diodes, were very
cost-effcciive when compared with commer-
cial transceivers (e.g. the Gunnplexer). 'Hie
main disadvantage wa.s the "plumbing-" li
took a lot of time and a fairly well-tooled
workbench to build vvaveeuide- based de-
Figare I , A GuAsFEJ osiillafor. G, D, and S
- gate, {tram, and , source respect tveh\
Figure 2. In a ya^l antenfta, the elements are
about a hulf-waveiength long.
16 73 Atnateur Radio Today • July, 1 994
signs. For instance, some pans, like the
screws used to hold the diodes, could only
be made w ith a lathe.
However, if you were ever drawn away
from ihc 10 GHz band bv the mechanical
difficulties, this article is for you. The 10
GHz transmitter we are describing could
hardly be simpler.
The GaAsFET Oscillator
Trying to design a GaAsFET oscillator
with PUFF, a computer program previously
described in this masa/ine, we first consid-
ered a design like the one in Figure 1 .
Like in many oscillators, the oscillation
lakes place if there is an adequate feedback
from an amplifier's output to its input. In the
oscillator shown in Figure I, the feedback is
provided by the two close-coupled stubs
connected to the gate and drain mi-
crostriplines. The source terminals arc con-
nected to the ground plane-
Making tfie Oscillator Radiate
Any conducting patch etched on a PCB
radiates a pan of the energy it is fed with. If
the dimensions of the patch are small in
terms of wavelength, little energy^ is radiated.
As the patch dimensions increase, radiation
increases too, until a }J2 patch dimension is
Cofuinued on page IS
Figure 3, The oscillator circuit dhnensions. (See text.)
Feedback
!n ouf oontinuing effort to pre&ent the best in ama-
teijr radio features and columns, we r&cogni^e |l>0
need lo go directly to Ihe source — you, \!hB mader. Artl-
des and columns are assigned feedback numbers,
wtuch appear on each artide/co^min and are 3^0 list-
ed here. Th^e numbers corr&spcnd to those on the
feedback card opposjde this page^ On the card, pleasd
check Ihe box which hctnestly represefits your opinion
of eadr arijde or column.
Do we realiy read the feedtacfc cards? You bell
The results are tabulated each month, and the edHofS
taka a good, hard look at what you do and don't like.
To show our appreciation, we draw one feedback card
each month and award the lucKy winner a free one-
year subscription (or extension) to 73.
To save on postage ^ why not fill out tlie Product Re-
pol card and the Feedback card and put them In an
envelope? Toss In a damning or praising feller to tie
editor whi1i5 you're at it. You can also entar your QSL
in our QSL of the Month contest. All lor the low, low
price of 29 cent si
1 Never Say Die
2 Letters
3 QRX
4 The Global Positioning System
5 Worlds Smallest 10 GHz ATV Transmitter
6 eMt/RFi Defense Strategies fOf Hams
7 Review: S & S Engineering's Frequency
Counter Ki!
8 Review: LDG Electronics" F01
9 Delayed Video Trigger for Your
Oscifloscope
1 0 Muitiband Halt-Wave Delta Loop (MHDL)
11 tcT^HOved Resonant Feediine Dipofe
12 RTTYLoop
13 Man^ats
14 Carr's Comer
1 5 Hams with Class
16 QRP
17 Packet & Computers
18 Homing In
19 Ham Help
20 ATV
21 Above and Beyond
22 Dealer Directory
23 Ask Kaboom
24 73 International
25 Special Events
26 Barter n' Buy
27 New Products
28 Random Output
29 Propagation
ARE YOU BUILDING A
t ISiii AfJi
X-BAHO TRANSMITTER
Miniaiure (2V4 % 3^k x
r}GaAsmiaostrip
ftransmitter pro-
vides 10 dBm centered at 10.525 GHz.
Integrated microstrip patch antenna elimi-
nates tha need for an external antenna.
Advanced matching techniques secured
good temperature stability wrth fowf requenc^
pulling. Great for long-range testing o( radar
detectors, calibration of radar receiving
equipment, and point-to-point communica-
tion links.
Compteie Assembled System. $39,00
Pans i Instruction Kit $29.00
Pius $2.00 Shipping and Handling
INNOTEK Inc.
P.O, Box 80096, Fort Wayne, IM 46S98
(219)489^1711
Visa * MasterCard - Check * Morvey 0f{jer * COD
Money-Back Guarantee
CIRCLE 2S3 ON READER SERVICE CARD
Packet Network?
AN 5 h05- lh& hBrd-to-fjnd parts ttiat make building a
Packet Network easy*. Usir>g ordmdiry Packet TNCs wrtfi
ner^vorit software tnsialled you loo can (SJipafx:! ihe extsling
nerkVOFk. w stsfl your ownf
Ihr VETRJX
r I mill 1 1 —11 I iiiji
9¥ rQavecfofT.
. - gti!Aa«!faaifaCTT^ieNETflt|ICl^tf iiMii*ii3tiliwte.Ciii^iactii
' 134.93 zi^-irihkd Adt^im fir DRSI or jblFr. M*9 ckK ■ specify
Other useful products f&r mfwork bidtdera indude:
Pnvirr Siippti fVT ih£ TKkk T' Vcl Um* kxhm, *llh TNC CH^ \i t A ¥<^
\.'\ *."- ^? iiiJii'irtJ VVirc.VtiKltfn ^ J4pttf.ti;»f»ettiTNCstiPE?rtm"^iicr
* rt: - n nc Ml'iljm Qi^uaoELl t-. --.,:." ■ Sc: ■ I iH. II I95 kllii; T>TtD Rddici.
t jWci rSl -tni Jl S l ^ Ltl. ST V"^ j*M:rtii">l.c J I . RS-Ul Timeoul Ftiner
fr^'v.-'inrs con;pjijr-trjtofid jpplKAtNmt f|i»fti leK^in^ ufp a ThcNET Maim
H = 'J? birr E?D;Hd. ^1*>.^5 kiL 144.95 4BiKTntskid., Opifimd ttase $1235];
PawcTD»tfibuli«fl Board ta^y. cvem4 trrnvrnieitE 1 1 vi'fr p^'wersflltriNftirFri
i^\^. "^^ ki L. S24.9'j Jise m f>k.d i . Mcf workint Sflftw^rt. TNjcuincnt^tion and
PLEASE WRITE FOR OUR FREE CATALOG
To order, send check l^- mi ) (US Funds) fldd S3 S/H. NJ
address add 6% laix, Ml US ordors shipporj 2-Day airl
Your Sattafaetion l» Fully Guarantged.
Amateur Networking Supply
Post Office Box 219. Montuate N«w J«r$ey 07645-0219
QRCLE 76 ON READER SERVICE CARD
-o
1 ANTENNA - 9 BANDS
NO TRAPS - LOW SWTt
CHOOSE BETIVEENSWW Ott IKW VERSIONS.
INSTALL HORtZONTAi,LV OR A5 AN
I^^^RTED VEE, SWR y$yALLV BETTER
THAS 1^:1 OX MOST BANDS. Ol"R SPECIAL
R.\LVS MATE UES \OVR SO OHlVr FEED LtVE
TO Om HIGH I MPltDANCE OFF CE>rrEll lU)
\ITSDOM ASTESSA. ALL ANTENNAS COME
WITH A 3 ^'E A« LIMITED WAfIRA VTV' AND A
10 DAY MONEY BACK Cl'AKANTEE. WRJTE
FOR %OLTt FREE DATA REPORT TODAY.
SHOW'S TECHNICAL DATAp ACTl^AL SWTl
CLiR\^ES, CUSTOMER COMMENTS AND OLTl
LOW LOW EACrORV DIRECT CANADLAN
PRICES.
GAR ANTENNAS
RR #14 MAPIJ^WARD ROAR
THUNDER BAY, OM ARIO
PTli SES
PHONE (807) 76S-S164
CTRCLE 3^2 ON READER SERVICE CARD
SAM
Amateur Radio
Callsigo Database
Ftnd Hams qulclrfy and easily by Calteign or tiy
Name. Search for a specified Crty, State, Of Zip
Code. Prim witti standard or customized output
Ide^l for mailing lists, QSl's etc MEW FOR 'S4.
search niters that allow you lo specify FIRST NAME,
LICENSE CLASS, AGE, ADDRESS, or CALL
SUFFIX, AREA. OR PREFIX
S^ AT Option fil^ ificlude County Cross Reference,
License Eatpiralioo Date, Full Date of Sirth.
Previous Calte and Dale Firal Licensed
Requires IBM Compatible PC. 1 7.5 Me of hard
drive space ^ and high-density floppy drive.
NOW AVAILABLE ON COAOM
Disk Version $39.95 CD-ROIVI $39.95
5;^M OPTIONS $7.50 each
Shipping and Handling 15.00
RT SYSTEMS, tNC
6207 STEPHANIE DRIVE. HUNTSVlLLE, AL 35Q02
1-800-725-6922 or 1-205-eS2'9292
Visa MastefCard Of Oisccver
..beoause
QUALITY
is important
tsJEW 1
ital
EUR" AM cLECTROf^ics
m. FAK
B03-2T^i;>-l3*4
PacketPeT
For Windows
PC Termifiai Software For Your TWCl
• Use up to 4 TAPR. KAM. MFJ,
PacComm or PK88/232 type TNCs
in any combination simuttaneousty
•/ Muttiple Connect Support, Logging
^ Integrated Text Editor / Viewer
^ Binary File Transfers with Ctiat
^ ANSI Color Graphics Support
^ Macros & User Definable Menus
^ Seiectabfe Fonts 8, Colors
^ User Manual & 1 mb of Online Help
$49:9i + $2.90 Shipping & Handling
Florida residents add sales tax.
Please Send Check or Money Order
and your Annateur Call Sign to:
ChucH Harrington Software, Inc.
1565 Brazilian Lane
Winter Park, FL 32792-2309
(407) 679-9017
CIRCLE 355 ON READER SERVICE CARD
n4
R
EC TOR riNDEH
ZERO-IN
THE SIGNAL!
HAND-HELD
PHASE SENSE
ANTENNAS FOR
VHP DIRECTION
FINDING, USES
ANY FM XCVR,
COMPASS GIVES
DIRECTION,
ARMS FOLD FOR
STORAGE- TYPE
VF-142 COVERS
BOTH 2-HTRS S
220MHZ, OTHER
MODELS AVAILABLE.
WRITE OR CALL POR
MORE INFO.
$3,50 SHIPPING & TYPE VF-142
CA. ADD TAX) $159,95 6^9-
RADtO ENGINEERS 565-1319
\
3941 MT, BRUNO AQE AVE.
SAN DIEGO CA.d2111
CIRCLE SB OH READER SERVICE CARD
73 Amateur Radio Today • July, 1 994 1 7
World's Smallest 10 GHZ
ATV Transmitter
Continued from page 16
COUPLED
V LINES
A
?
COUPLED
\ LINES
/ B
Figure 4. For PUFF, !he osiiUaior is an am-
plifier With two pairs of coupled tines con-
nee ted end-to-end. Various A ami B lengths
were fried, wit it the overall !en0i 4 + B re*
maining X/2,
feached. Thh is when radiaiiun efficiency is
at its besit:.
This principle is not new to us: Yagi an-
tcfuia ekmcnis are also about X/2 long (Fig-
ure 2) and they are particularly efficient
when it comes !o radiating energy from our
transmitters! Radiation from microstrip ele-
ments is used in so-called miiTosTrip anten-
nas.
What we tried to do here was to combine
the design of the previously mentioned os-
cillator with n microstrip an let hill Two mi-
crostrip antenna patches were designed
close-coupled lo each other. I'hc GaAsFET
input (gate) was connected to one, and the
output (drain) to the other, thus obtaining ihe
following design t Figure 3).
We decided to make both patches w ith the
same dimensions for our first try. In fact,
this is questionable, because if the two
patches radiate widi opposite phases, then
their respective radiations would cancel each
other!
Perhaps a more in-depth theoretical (and
mathematical) approach would be needed
here.
However, experimentation showed that
some radiation did take place. In fact, some
mutual cancellation from the i\vo patches
can be desirable if it is thought of as equiva-
lent to Limiting the output coupling of a con-
ventional oscillaton Ff all possible energy is
coupled oul of an oscillator, its stability will
be bad, because its characteristics will be af-
fected by the circuit it is coupled to.
Designing the PCB
Now, there are four dimensions. A, B, C
and D (FiE[ure 3 1 we must decide.
We described the circuit to PUFF in the
Feedback
Microwave
Radiation
Microwave
* Radiation
video
Input ^
1
pF
33
PF
\
_ IK
■
10K
Gate Supply
6
Drain Supply
All parts marked wtth an asterisk are etched on the pcb
All discrete capacitors and resistors are SMDs.
J = Connected To Ground Plane.
SOURCE
GAT
DRAIN
SOURCE
I
CHIIII
33p 20
V VIDEO GND
INPUT
+V
Figure 5. a) Circuit schematic, h^ A drilled and etched donhle-sided PC hoard for this pro-
ject is available for $5 plus $130 S&fl per order fi-om FAR Circuits, 18N64(} Field Conn,
Dundee (L 601 IS.
18 73 Amateur Radio Today * July, 1994
ORDER NOW 1-800 4 HOBBY KITS qrp amplifier
• 2 Meters
• 233 MHz
• 440 MHz
• 6 Meters
- rn r r-i i ■ i
FX-50 kii (6JVIetefs)
FX-223 krt (1 1/4 Meters*
CFX matching case set.„
FANTASTIC
FM TRANSCEIVERS
Ramsey breaks Itie price barrier on fM rfgs! The FX b Ideal for shack,
portabJo <jr mobilq-. The wide frequency coverage and programrrtBDle
r&f>eatDT splits makes the FX the perfect rig lot Amateyr, CAP or MARS
appEiciiEion^. Racketeers really appreciate Wig dedicated packet port,
'TRUE-FM" sign^ arid almost instanl T/H smxtitm^ Higfi speed p«d(St?
...Nci proWem. Twelve d«o^ pfograrnmed charinete. 5W RF otrfput
senstFvi! dual conrvc^r^Kni mectivQ' and proven EASY assemWy. Why pay
mow tor a used lofeign rig wt>en you can have one AWERICAK MADE
iby you) far \g^^. Comes cDtuplete lets cas« cind speaker mike. Order
□ur maiching case and finol3 sei lor that pro look.
. .....S149.95 FX'146 kit (£ Meters) .„.„,„„.„„„...„,. .$149.95
„...St49.95 FX-44Q kit (3/4 Meters) „..„ S1 69,96
^S29.9S FXM-1 . tCOM/Yaesu style speaker m*e SM.&S
For a slick little QRP boosi. use one o^
the 20 Wall amptifiers. Needs only
1/2-2 watts of dnvo for full Oulpul,
linear for SSB, AM m CW operation,
power MOSFETs for tiigti ettieciency
and mLrrirsiage low pass fiFter lor a
clean signal. BuUt-in Tff\ relay for
aulon^stiic switctiing, runs on 12-15
VE>C a! 2-4 amps. Add our matching
case set For a complete staijon look.
VotrrchCHce of bands. ^., 549^95
Specify band: (Q AMP 20. 30. 40. dO>
CQAMP Matctimg case set $14.95
2WAY RADIO
SERVICE
MONITOR
iQw^cosi ttrvice monitor Fof
triops big or small the COM 3
delJveF^ advanced capabilElies
for a lantaslic pnce— and our
new leas^i program allows you to own d COM-3 fee less Ehan
S3 .00 a day. FeaturEiS • Direct entry keyOoaid iMth programmatil^
memory > Audo & Iransmitter frequency oounier *■ lED bar gaph
ktqi^aoi/mat devcbon d^ibfy " O.t-IO 000 uV output levete '
High fecerve seulMjf. kss ihan 5 ^V • too khU lo 999 9995
MHz * Coniinunfi fpet^rency coveradfr • Tramrai protediCHi. up
to too watt$ - CTS lone enc^xtef * 1 luiz and #iitennl moduidTior^.
COM-a 2 Way Radio Service Monitor „ _. .52995.00
2 MTR & 220 BOOSTER AMPS
Here's a great booster tor any 3 meter of 220 MHz hanp-heW unji. These power
boosiers deFiver over 30 waits of output, allowing you to hfl the repeater's full quieting
whrle the tow noise preamp remarkably improves reception. Ramsey Electronics has
sow inousan^s ol 2 meter amp kds, but r>ow we offer completely wtred and tested 2
meter, as weU as 220 MHz units. Bolti have all Die leatures ol Hie higtt-prtced
boosters ai a fract^n dt the cost
PA-tO 2 MTR POWER BOOSTER (10 X po*er gainj
PA-2O220 MHz POWER BOOSTER (8 X pwcf gain) FuJly wi rod & tested ...„„.„. S99 95
QRP TRANSMITTERS/HAM RECEIVERS
20. 30 40. BOM
CW TflANStyttTTERS
Join ih« tun on O^P* Thousancfs of
ihese mmt-ngs ha've beeo soltf and
ions oT DX coniflcts have been made.
Imagine worhmg Eastern Europe wtlh a
S3Q iransmiiter— thars ham radio at its
best? These CW ngs are K^al mat^ io
the receivers at ngflt They have two-
pDsitiian variable crystal canirQ<l (one
popular ORP XTAL incfcidc($}. one watt
output and buflt-in antenna switch
Runs on laVOC. Add our maiching
ca^ and knob sel Tor a handsome firrisbed look.
Your choice of bands
(Spectly tjand QRP 20 30. 40, or 80).. S 29.95
Matching case knob set C QRP ^14.95
20,30.40. SOAff
All Uocfe RECOVERS
Bufid yat/r own rn^ni tiam slalio^i Sen-
siTrwe all-riKKle AM, CW, SSB receivers
u?c direcl convefsion design wilh
N£6*2, IC as fealured m QST&t\ti ARRL
handbooks Very sensEiive varactor
tuned over entire ban^. Plenty ol
speaker voUime. Hyns on 9V baitery.
Very EAS^ to build, lots of iun and
eauciaiional^-^deal tor beginner or otet
pio. New 30 page manual. Add the case
set for welhftiied professional look.
(Specify band: HR^ao, HR 30, HR^O,
HR-80J „.„.„.*-
CHR, Matching esse *....,
..S29.gs
.S14.95
Miniature
SPEAKER-MIKE
Fits Icon,
Yaesu. Almco.
Ramsey and
Radio Sriack
r^^ LnoUngtof
a handy little
Speaker- mike Io
c 0 m p H m e n t
yoyr FX trans-
ceiver or othef
ICOM style
ha naie- talkie''
The Ramsey
SM-t s- ■ ' -!Ttiks s a beauty its only i i/T
Wide iiy i i.^ inches higti and nas a Usji^f dp
on the back so yoii can easiFy clip it lo your
lapel Of shirt its small iniemal speaker Jsn1
going to break any eardrums but is very ckyar
arKt has plE^ni/ of pop lo b€ heard when worn
There s even a jadk on tl^ mk^ so wtien fou
plug 4 in, you sil tave the use of ihe speaker
lack from your raflto F4s an Radio Shadt,
tCOfcl Ymsu, Mficoand Rarnsey ngs..
SM-1 Mmi'Speaker mike.
Fully assembled , „..SZiM
CW KEYER
Send perfect CW. Microprocessor keyer loatures 4 programmable
momories gf up io 26 words each. Iambic keying, dot-dash momofy.
variable speed from 3-60 WPM,. mi^mtsb^& sidctone, keying to any rig
and fgily RFI proof EAROM rnsRiory Iteeps message? up 10 t QQ yeais -
youii $0 sitent before me tcey' Indudes butD-in touch poddtes or itse
your own. Ea;sy ^tsemb^ and matchingi case set avar^bfe for a nice
Station look.
CW- 700 Micro keyer k it S69. 95 MK Matching case set. .. .. S1 4.95
CW-700WT AssembJed CW-TDOand case S1 1 9.95
ACTIVE ANTENNA
Cramped for space? Get tongvftre peHoriTiance witfi ttiiis desktop
antenna. Properly desigr^ unit ti-as dual HF and VHF csrcmiTy and
buklt-in whip anieftna^ as wei as evtemai lACk RF gain^ cent rot and 9V
operation makes unit ideal for SWLs, travoring ttams or scannoir butfs
who need hotter reception. Ihe malchtng case snd kncjb set givus the
unit a hundred doJIar lookF
AA^7Kit._... S2a.95 Watching case & knobset, CAA. S14.95
SHORTWAVE
RECEIVER
Fdntastc ^iK;crver that captures the woild
With iusl a 12" antenna! Can receive any 2
MHz portion from 4-11 MHz. True
superhei, has smooth varactor tunirrg,
AGC. RF gain conirof. pLeniy of speaker
volume and runs on a 9V battery.
Faso rating Seoul, schod or dub prqea.
provides i>Oijrs (rf fur^ for evert the most
serious OXer. For the car, consider our
shortwave converter. Two switchable
bands (in 3-22 MHz rangoi each 1 MHe
wide — lunable on your car rad»o dial Add
some Interesl to your drive horned
Shortwave receJvsr kit. SRI......... S29.9S
Shofti»a« converttr kit. SCI ., ,. . S27 . SS
Usiciir^ esse set fv SRI. C$R .. S14 95
MaHclnrvg case set for @a. CSC -SI 4,95
AIRCRAFT RECEIVER
Heat CJ(CJting aircraft
comrnMnications — ^pick up planes
up to too miles avv^y! Receives
1 10-13fl MHz AM air band,
smooth vanacjor lumng superset
wrih AjQC. ce^aiTHC fitter. ^d:ustabte squek^, exoet^t sensifiivtty and i
lots of speaker volume. Runs on 9^/ battery Gicai lo^ ait shows or
^LfSt hanging around tfie airport! New 3&-pago rnenuaJ deTa:!S pilot talk,
too. Addcase sal for 'pro' took.
AR 1 kit „... .S29.95
Matching case set, CAR ,. S14,95
2M
POWER AMP
Easy 10 tHJik) power amp has 8 times
power gain, tW in. SW oul 2W in, 16W
out, 5W is for 40 W ou'l. Same amp as
featured in many ham magazine an Ides.
Complete with all parts, loss case and T-
R relay
PA-1 . -iOW pwr amp kit..........™. S34.9S
TR-t. RF sensed TR relay toL^SI 4.95
MORE
KITS
NEXT
MONTH'S
ISSUE
FOXHUNT HEADQUARTERS
Locale NtUen or inJcnown i^nsm^crs iasL Tt» FoxticMit cbectiOii
tn^ connects lo the antenna and speaker jac^ (xi any twfe fecewer.
AhA or FM from 1 MHz to 1 GHi The aritenna (a pair ol dipote
telescopic whips) is rdatcd iiniiF ihe Hull meter stxjws a mmimum. A
pair ol LEDs indic^ie lo lurn Lei! or Rigfrt. The Foxhound is Ideal lo use
ivith & M^alkic-talkie. if yoM wish Io kanismit, go ahead, a bulll-in T/R
swilch senses any transmitied FIF and switches ttsetl out of circuit vvhHe
pts talk. 11 doesnl get any easter Ihan Ihcs' We pn^^ide ait parts e^ecept Nr a tew feet of 1j^ nch
FVC pjjpe avtalaUe at any hardwar e store br a 6s&Bit or tvra Add our maidiing esse set fer a
ayrplete fifMHed un4 Be the one w|h the ansvto, «m these trs^smma^ HmM and \tdA down
ttose jamrnefs. ycajl' do it gs ^x^ y^ur F^-aefiound. ^_^^__^
Add some Inn Id ycrur ctut^ events by tiaving a transrtitfia hyiti foxtwming is a craze $weepin^ The
nalion, bill many cfubs are mtesmg oul on the act»Dft because they lack Ihe expertise tir lime lo
develop their own foxhunt transmitter. We set one of our mosl dovbus and sneaky engineers lo the
KiEit of de&iigrteng an easy to Puik^ and use. yet highly capable Foxhuni transmitter. A snazzy
microprocessor controller ttas both preset and prDcpammabSe trarwmisaon characteris^tics allowing
j'Qu tQ easily set llie d^flKt^ (eve* from T>e9irjTc^ !o kJicw-^-aTf Ttie S^Fox, FHT-t. ss cry^
cont.'c^^ed m the 2 meter band (oystal for I4fi ^ indbded) mA ■ power otHpii of 5 «ll& nt il
a^ustalile bf ^ oomroBef The irsnsmt^cr o ptngiainmed to ID in CW or add our vo<» optxw i
you reafliy want to aggravate Ihc troops - "Ha ha. you can! find mef Join ifie fun. gel vid tif Itiose
sjuf^ old iTwetPngs ard picnics tiave a fexhyrii'
OF ' 1 FoKhound dircctJon finder kit .S59:95 C D F W atching case set for DF-t ,. . Si 4. 95
FJHT't SJyFojc Foxhunt transmmor kit.S129.95 FHlD-1 Voice ID option ,....S29,9S
CFHT Heavy dy^ mctaJ matching case sel for FH T-l ..^^,.... ............$29*95
PACKET RADIO
Two new v^fsbns are available tor the Commodore 64 (P^A) or Ihe l&M-PC f P-IBM} Easy as-
semt^ fiO TUNiiNG' . hiciudes FREE disk software, PC Board and Full Documeritaiion Kn form
P^A.... S69.95 P IBf^ S59,95 CASE CPK ,. S12.95
T
STEREO FM
TRANSMITTER
Run youi own Stereo FM radio stationf
Transmrls a stable signal in the BS-t08
MHz FM broadcasi t^and up to t milQ.
Detailed manual provides helpfuf info on
FCC regs. anienna idea? and rang« to
e^pecL Latest design features ad|ustabJe
line level irtpot^. pre-emphasis and
crystal controJled suboamer Conr»eas to
any CO or tape pFnyer, mike miner or
radio, fnclirdes froe tuning looi too! For a
pro look a<M our matchcng case sel with
Or^-toard whip antenna
FM-1 OA Stereo tfansmiiief kit . S34.9S
CFM Case,wti^ ant set... SI 4. 95
SPEECH
SCRAMBLER
De^aamb^ most scramble systerrts heard on
your scanner radio or set up your own
scambled communicalien' system over the
phpne or radio. Latest 3fd generation \C is
us@d kt fantastic audio ctuaiicy - e^uivaEent lo
over 30 op^amps and mkers^ Crystal
controlled for oysttl Gtear sourid wrth a bciit-in
2 wan wcio «fT9 tor c^rea ratto hook-up. For
scrainble systams. each tr&er has a wnit tor tui
duplex operahon. Coirirmifucate m pnvacy with
the SS 70. Add our case set for a fine
profos^ional finfsh.
SS''j Scrambler ^descrambJerkit .339.95
CoSD matching case sat...™ S14.95
SS-70WT Assembled
SS-70 and case set .™™, S7S.9S
MICRO-MIKE
World's smaller] FM wireless pike,
Srnailer tttan a suQwr cube ■ incitiding
baliery and mike Two $ets oi SMI
pans ELipplked in case jicmj a/e ckimsy'
l&r^fK audio pick-up (pin drop at 5 ft)
and tiwiszim onge of 3CI0 tL We ndude
Ihe baitery fwaich sytcl, eiectrct mite
arid even a Tuning ton)! 8e a James
Bond and fcarr^i BUT tool
FM^S l\4cro miko Wt St9.9S
CRYSTAL RADIO
Relive the radio past with a crystal set like your
grandfather built. Use* genuine Galena crystal and
catrthisker. Several ditfercrtl types of radios are tkiiJt,
I '^eluding standard AM broadcast, shortwave and
even WW It loxhote styte. To compare modern
semicOTiducto^ detectors, we include a diode for
compahson No sddenn^ required and wc even pve
antenna ideas. Radio lor tree, get it now before
Clinton tastes ill
CS-t Crystaf set kit = , Sig.9S
DR. NI-CAD CONDmONER/FAST CHARGER
Ql - lino big tn^fA for refinement battery packs. rEjiuw?naie and condibon yoLi battows
for ,.A,^^, capacity. Advanced drcuitry has optimized discharge Del ore charge lo eferminate
memory effect and to cisflditron bfltterJes Ihai have been poorly cared for in the pasi. Quick
■charge rapidly bnngs battery to lull charge in (ess than an hour-iust 15 minutes for some types'
And lop-off' charge rnode squeezes every last tat of cneigiy irrto each cell f Of the ab^iute n>Qst
capacity. SAHch-mqde tegulatof controls constant Ctfr^m charge whie bemg monilored by i
negatrve defta-V Eystem it?ai cJa. off Ihe Jast charge at the exaa point o* fcJ charge^ttenes
are charged, nci qq(*£0 Charges NCads or «*#* iMte tan 2 to iO ceb (C3Siy expanded)
and ctrrent capacTt^es up to 10 An|H»ufS Runs on 12 to 15 VOC Quit ceokirtg y&f baneries.
it>uying new packs, waiting hours tor recharge, gel a Or. Ni-Cad today' Available in money
saving kit fomi or wired and tested with case at a special price. Kit buitders: add our matching
case set for a snajjy finish.
Dl^-t Dr. Nl'Cad cor>ditioner/fast charger kit... „^ ..*...-.., ,....549,95
CDN Matching case set......... , .^*.....,.....^^^^^.^^ - — Si 4.95
DN 1 WT Futty assemPJed Df. Mi-Cad vtHh case.* ,„„,..- $69,95
MINI KITS
Ramsey carries a complol£.^ fme of tow cost,
easy to build, easy to use functional kits that
can be used alone or as building blocks in
Harger more corrfilex Oe^gge^. Miini-klita include
audio amps, tone decoders. VOX swifches.
t^Twis, au(£o alamis. r^oise-^nakers and even
shocking kits^ Call for our free calalogue!
ORDERS CALL 1-800-4 HOBBY KITS (446-2295) ORDERS ONLY
TECH/ORDER/INFO (716)924-4560 FAX [716)924-4555
'wjiTsj-^I TEHMS; Sntl^laction guflrant«#d Eiamina tor to dayji if not pkinsed returfr In Qriglnri] fonn
^ jj lor fftfunid Add $4.95 far shipping, handling and inmurance For lareign otxiers. add M^a iot
^^ <iarf^K4 mail COD (U S antv) adO S5,0Q Ottfers undar S20 adid S3 00 NV re&^denls odd 7%^
^1 Hil«a tax, 90-^9f parts wsranry qh lit partL t^yar psfls & tabor vrtrtat^ Vf wifed units.
RAMSEY ELECTRONICS. INC 793 CANNING PARKWAY VICTOR NY 14564
CIRCLE 34 ON READER SEVICE CAJ^D
^m
"IKEA''
parabo I i c
d i sh
c
osc
((('h4
50
cm
1 c
reoB ; ver
horn
a 9 n I a !
Figure 6. The tesf setup.
,13; SB; 4? 31 JUL 1693
ATTEN ID eta
REF »0 dem
FEAK
LDS
10
■ ■■ ' -
ITA SB
SC F3
9,712 GHl
-3«0S dBm
1
CE^^'ER S.710 bhz
RES B)4 3 3»#HZ
VSW i IIHz
SPAN I .CSS BHZ
figure 7. The signal at the receiver.
follov^ing way {Figure 4):
First, the coupled lines A and B were cho-
sen with ihe same low impedance. Low
impedance means ihat ihcy are broad, like a
microstrip anienna paich* Ditiiension
B+D+B should be equivalent to nbout a half
wavelenaih to maximize radiation.
Second, to generate enough feedback for
oscillation lo occur, rhey were chosen with
tight coLtpling. which means close to each
other Tliis deiennines dimension D.
Ttiird, the overall electrical length of bc3dl
tines put end to end (A) was chosen at about
X/2 to maximize radiation. The point at
which the GaAsFET was attached to the two
patches (dimension C) was searched with
PUFF, by trial and error, so that S,^ feed-
back was as high as possible.
Finally, we decided to start experimenting
with the PCB pattern shown in Fig-
ure 5.
As an aerial we used an aluminum
parabolic reflector an *iKEA'* dish, sold as
a lamp, available cheaph in fumilurc shops.
fEdi!or*s note: The authors' QTH is Switzer-
land, You may have to improvise if you can-
not find the fKEA lamp hKally-l The diame-
ter of this lamp dish iis 40cm and its focal
length is rather short, at about 1 1cm, So F/D
is low, at 0.27, The oscillator was simply put
at the focal point, so it would illuminate the
dish ... no more '"penny feed." 1 low is this
for simplicity? (Figure 6),
Tlie GaAsFET we used was a "Red Spot*'
from Birkelt, 25, The Strait. Lincoln LN2
UR UK,
Dimensions D and B (Figure 3) were held
constant throughout the tests: D ^ 0.5mm. B
= 10mm,
For our first test, we took A = 18mm and
C - 6.5mm. With +V supply = 4 V and -V
supply ^ -3.5 V, Id was 23.4 niA and we re-
ceived a -3 dBm signal with our hom anten-
na,
Osciifaiion frequency was lower than pre-
dicted at 9.712 GHz (Figure 7), The re-
ceived signal was best with the oscillator be-
ing shifted away from the focal point, at
16,2cm instead of 1 Icm, This probably
means thai the radiation angle from the PCB
Is too narrow to illuminate the whole dish
evenly (Figure 8).
Eventually, the GaAsFET failed (it did
draw quite a lot of curreni) and was replaced
by a first-class, expensive Cl^' 1 8-23 from
Siemens, A was left unchanged at 1 8mm
and C wa.s tried at 7mm. The received signal
was much lowen at -17.3 dBm, With C ^
8,5, the oscillations stopped.
Most interesting was the fact that this
small change in C brought the frequency al-
most 1 GHz higher at HX653 GHz.
We replaced the CFY 18-23 with a new
red-spot GaAsFET, with C left at 7mm and
the frequency remained the same, so it really
seems that the frequency shift comes from
the C modification, rather than the GaAs-
FET change.
To lower the frequency down into the am-
ateur band, we fitted two small pieces of
copper foil to the ends of both patches, in*
creasing the A dimension to 19mm. This
brought the frequency to 10.293 GHz. +V
supply was Hr 3.5 V; -V supply was -4V; Id =
16.5 mA.
Figure 9 shows the received signal when
ihe oscillator is frequency-modulated by
sending a 4.5 MHz sinusoid to the gate. Lin-
earity is acceptable.
Modifying the power supply voltage did
not change the drain current much, Frequen-
cy did change but not linearly.
Figure S. If the osciiiator is placed fimtur from ihe parabola than the
focal length, it iUwninates tiie dish more evenly.
JMi Am =2 03 AUe 1992
'^ MKn-THK 10.3933 SM^
ner ,0 ciatn at ten ib hb -i7.s3 dSm
10
t
— — ^1
1
■
i
;
MASK EH A f
10. £933 GHl l\ 1
-17.23 dBm 1 U
\h
%
1
r
%
WA S3
SC FS
r^^vMl
fVHr«-i
^^^^
V
1
vw
DHft*,'^
l^Jh^
Mjy
CORR
.
CENTS
J
R 10.293a 0-tZ SPAN 102.0 MHt
RES 0W 1 MHZ VSH BOS HHZ &HP 2^3 wmac
'
Figure 9. Output sigrutl when the oscillator is frequency modulated.
20 73 Amateur Radio Today * July, 1994
KITTY SAYS: WE ARE OPEN 7 DAYS A WEEK
Saturday lO-Spm/Sunday 11-4 pm
Monday-Friday 9 to 6:00 PM
Come to Barry's for the best buys in town
For the best buys in town call:
212-925-7000
Los Precios Mas Bajos en Nueva Yofk
WE SHIP WORLDWIDE!
Export orders expedited.
IC-RTIA, R7^ nVOO, RTOOOA, B710OA, R90O0A,
IC'72S, 728, 729. 735. 737, 765. 791. IC229H,
IC3230A, IC901 A, GPS Receiver: GP-22
Wherever I go, I take my radio-
Specialist in RADIOS;
Business marine aviation,
ham radios and scanners.
CONTACT US FOB TWe UISTE5T tN
BUStN£££ AND HAM RADIOS^
SMOfmWAVE flECtlVEJ^ ft
SCANNERS ^ UOTOIWLA, iMESU,
DAflD.HAJtOM, PELM, SI
KING. S<MV. SANQCAr^
■
J
'>4i:.E.
^ ^ ^
^ ■ 'JOftZ
~ " S T f^ r^
I II
KENWOOD
"YAESU Ham and Business Radios"
FT-767GX, FT-890, FT-747CX. FT-990, FRG-8800,
FRG-100B FT-736R, FT-tOOOO, FT-416/B16, FT-530,
FT-5200, FT-2400, FT-470, FT-530- FT-411E
ICOM
ANTENNAS
A-S, A£S. CifSN^ra^. H^ia^.
H'JSIter. KLW. UETZ, Lktan
lylOOUBLOX. JQHHA, SiK^nrnt,
MulH-Band
YAESU
FT-23Fy2e/7e
FT4I1 £-611-011
FTH-a0O8/70Oe
ICOM
IC2/3/4SAT
IC02AT^2SFIA
IC^/4GATQ4AT
fCA21/U16
"TSrSOS"*. T&450S/AT, frSODO, TS-05OS,
TV 24f /A/441 A. TR^TSI A, Kon^^ood Service
Ri|M^, TSf 40S. TSe90S, RZ-1, TS-790A,
TS9S0SD, T>l-7aA, TH?8/4aA, 1^-941 A,
TM-741A, TM~732A, TM-641A, TM-742A.
MAfllME HADiOS
ICOM M7. Ml \. M56. M7O0frf, M800
AVIATION POfllAaLE ICOM A-^f
MOTOfOJ^ MARINE KH^GKX99
AOR:
9(H. 1000.
ICOM!
FI71A, R72A
RTDOQi
If cat
BudMrig Mil. Products
FLUKE 77. B3, IS. 17 MutUfllitCfft
Linear Amplifjer
Acnerjtron. I com. KenwoDd, Ygesu
Lsndrnob^lo NT's
JCOM U16 H1« VI 00,0400
MA^OH, MOTOROLA.
YAESU FTHaWiOOOB
UNIDCM REGEHCY. KIMG,
MARINE KZQM M7. M5«. M7t)0
AVIATION ICOM: A^l A200 H T,
TAD
Telephone Autopatch
Patches telephone calls from your
radio \o phone line. Great for mak-
ing and receiving phone calts
wtiem there ane rio phone lines.
Simple to use Write or fax for
Inquires.
Simpte)c, se-mi'dLtpfex. full duptex.
CES & CSI Models stocked: SDi-
50. PPV, CS700/800/900 etc Our
service Lab virili wire in s/slenis for
you it requested.
Save money on batteries.
Ask for Special Prices.
JCW2A
W2IAT
P2ATMAT
IC-H16/U16
l€21A
HOTOflOLA rUOfUS
nf>iHiwici^i,fuaos
TH-76A
FT-530
Shortwave Receivers
•SONVGRUNDIG
• SANGEAN • ICOM
Call 212-925-7000
Satellite telephone m suitcase
for worldwide use. WRITE,
Computer lfnerfa<;««
Stocked; MFJ'1270B,
MFJ'1274,MFJ'1224, AEA
PK-B8, MFJ- 12767. PK-900. PK-e32
MBX W/FAX. DRSi PRODUCTS
DSP 2232
Antenna Tuners:
MFJ, AEA AT-300,
ICOM. KENWOOD,
YAESU.
COMMEflClAi
a HAW
RSPEATERS
STOCKED.
1WWTEF0B
QUOTES
Kantrofiijcs
KAM PLUS. KPC?/a'4.
KPC240O. ^PER FfOi U.
KPC IV Data Engirw. D4'
MFJ-9a9C
8L8H. AT300, etc
Cover{:raft/Conxseal Stocked
SHORTWAVE RECEIVEftS
STOCKED
ALINCO DJSaOT, 120T, 162T,
460T, taOT, F1TH, DR570T, etc.
Telephone fcrsnib'tc-n
fqr cellular a nrd regular
CAB Stiif«o with
Stwnwaw
Wide selection of SW S Amateur
Publications
BIRD Wattmeters &
Elements In Slock
ANTENNAS;
AfA,A1phaDel!iL
ANUAiFtHiiu
(144, 220, 440
MHz), Isotoop.
EIMAC
3-5002
5728. 6JS6C
12BY7A&
6146B
BIRD
attmeters &
Elements
In Stock
MOTOROLA AUTHORIZED DEALER
KACHPNA COMMUNICATIONS OEALEfl
AUTHORfZED ampufiers
DEALER stockeejt
^n^ ^p^^^^ «- RF Concepts
SON Xf ,,tr.
Stiortwave Radios Stocked ^^ ^v^^^^^
DISrTAL FREQUENCE CUUNXeftS
OrrOELECTRONfCS mo<i0J 1300 H/A. 0-1300MHi
23O0. 2210 H. 0-22W MH2, 2600H . UTC-SOOO. 2S10
Radios for Business,
Gov't, 2-way, etc.
Stocked & Serviced,
Call for
Prices!
HEIL
EQUIPMENT
IN STOCK
Long-range Wireless
TeleptTone tor export in stock
BENCHER PADDLES
BALUNS. LOW PASS FILTERS
IN STOCK
MtRAGE/RFC Amplifiers
ASTRON POWER SUPPLIES
Belden Wire & Cable. Int'l Wire
OPTO KEYERS STOCKED
STAISIDARO.
Hy-GainTowere
will be shipped
direct to you
FREEo*
shipping cost
JRC Short-wave radios
J5T135« NRD-S35D
Ameritron Amplifiers
AMlRiTROMn
MAIL ALLORDERSTO; BARRY ELECTRONICS CORP., 512 BROADWAY, NEW YORK CITY, NY 10012 ifour blocks NfflrTMOFCANALST.BETWEEMSPfflNG and BftooMEsrj
New York City's
LARGEST STOCKING MAM DEALER
COMPLETE REPAIR LAB ON PREMISES
"AquI Se Habia Espanoi"
BARRY INTERNATIONAL
FAX 212-925-7001 Phone 21 2-925-7000
Monday-Fflday 9 AM lo 6^00 P.M.
Saturday 10- 5pfn /Sunday 1 1- 2pm
iRT/LEX-^'Spring SL Station*'. Subways: BMT-
■prince Si Station^". IND'"P^ Train-Bwy Slatfon'*
Bum: Broadway #6 to Spnn^ St Path^9th St./6tti Ave.
Station.
COMMERCIAL RADIOS
STOCKED: IQQM, Motoro-
la. MAXON. Sl«ndard.
Vsesju We serve munict*
palrties, ^sirissses. Civil
OeEense, etc. Poi^abtes,
mobiles, bas«$, rt^
peaters...
ALL
SALES
RNAL
We stock: AEA. Alinco. Ameco. Amerflron, Antenna Specialist. ARRL
Astatic, Astinn, B&K. Belcten. Senctier. Bind. ButtemuL CES. CushcrafU
Daiwa. Eimac. Henry. Hail, Hustler. Hy-Gain. Icom. KLM. Kantrqnics.
Kenwood, Larsen. Maxon, MFJ. Mirage. Motorola. Nye, Palomar, RF
Products, Shure, Standardn TUBES, Uniden, Yaesu. Vibrafle)?, Duple?(ers<
Repeaters. Scanners. Radio Publications
WE HOW STOOC COMMERCIAL COilllUPf ICATIONS SYSTEMS
HAMO£ALEn IMOUIRES INVITED PHONE IN YOUR ORD£» & GE REIMBURSED
COMMHCIAL RADIOS stook^d A «*rvlc«d on pr«fnl««B.
Amateur Radio Courses Given On Our Premises, Call
CxDort Orders Shlppad lmm«dfat«ly.
r
Technical he\p offmre4 upon purchafi«
FAX: 212-925-7001
CIRCLE 41 ON READEif SEftVlCC CARD
Figifri* 10. A preaffiplifier connevi^d to a
mkTostvip atitenmL
+V Siippiv
+3,0V
+3.5V
+4.0V
-V Supply ID
-4V * L15mA
4V 1 6,5 mA
-4V 173 mA
Frequency
10.363 GHz
10354 GHz
10.376 GHz
The received signal wqs best ai -17.23
cBni when llie PCB way ^ei ai 13.5cm from
the dish. The cross-polari/alion attenualion
was rather high* w ith a maximum of 30 dB.
The total radiated power was estimated at
about 1 mW: Replacing the circuit under test
with a Gunn iransmiiicr of 1 mW known
power output gave the same signal on our
lest bench-
We tried to further decrease C to 5mm.
this ^t\x the output power up about 3 dB and
the drain current down to i 1.4 mA. Oscilla-
tion frequency went down to 10.180 GHz,
which 11 11 owed us to remove the two pieces
of copper foil w^e had fitted to the patt;hes'
ends. This brought the fre^uenc) back up lo
10 430 GHz.
We then discovered thai the circuit was
radiating both on 10 GHz and 5 GHz! Wc
had not noticed this al first because the shoii
length of waveguide between the hom an-
tenna and the receiver was acting as a high-
pass filler; (cutoff frequency of f X 1/2"
waveguide is about 6.5 GHz). Furlher short-
ening the patches cured the problem*
Conclusion ^nd Furlher D€ve]opment!;
Well, this is it: We have made a seven-
component 10 GH2 ATV transmitter, possi-
bly a Guinness Book record! Stability was
good, with liiile frequency shifts caused by
moving objects near the TX- Although we
did not try it, temperature stability could
probably be enhanced by enclosing the
iransmiuer between iwo plates of expanded
polystyrene. This material has very small
losses al U) GHz. Another improvement
could be fitting a dielectric stabilizer to the
oscillator.
Simplicity is not the only advantage of
building a transmitter of this kind. Having
the 10 GHz source directly al the para-
bola's focus also avoids losses in wave-
guides, coaxial lines, transitions, relays and
so on.
This would be panicularly inieresiing in a
receiver. The preamplifier could be built di-
rectly at the parabola's focus, the dish being
illuminated by a small microsirip antenna at-
tached next to ihc pneamp (Figure 10).
As we know, any loss between the anten-
na and the prcamp severely affects the re-
ceiver's noise factor. An assembly like ihe
one shown in Figure ilb should be much
less lossy than* say. the one in Figure I ta,
and much cheaper, too, when you consider
the price of an SMA connector or a mi-
crowave T/R relay.
One last word of caution: As for all
GlAsFETs, it is highly advisable to turn on
the negative gate supply slightly before the
drain supply, because this keeps the drain
current at a safe leveL If the gate is left
at ground voltage, a large current surge at
turn-on could blow the GaAsFET. Mi-
crowave semiconductor chips are really liny
devices so their power safety margin is quiie
small.
Figure Ji. af A man- comemionat iand lossy) sefup. Note the I) waveguide losses, 2} connecmr losses, J) cmix losses, and 4> relay losses,
b} The preamp can he emiosed in its shielding box Mith a small microsmp element ^lued on the outside. The assembly is placed in from of
the pamhola with the mkrostrip patch at the focus.
22 73 Amateur Radio Today • July, 1 994
JZ.
COR POR AT I OIM
9 Autry
Irvine, CA 92718
(714) 458-7277 • FAX (714) 458-0826
MODEL VS-50M
ASTRON POWER SUPPLIES
HEAVY DUTY • HIGH QUALITY * RUfifiED * RELIABLE
SPECIAL FEATyRES
• SOLID STATt ELECTRONICALLY REGULATED
• FOLD-BACK CURRENT LIMtTIHG Protects Power Stjppfy
from ejecessiwe current & contmucjus shorted aiitput
• CfffiWBAH OVER VOLTAGE PROTECTION On all Wodels
ticept a^3A. flS^A, RS 5A. RS4L RS Si
• MAJMTAIN REGULATION & LOW RIPPLE at NJw Iin€ inpirt
• HEAVY DUTY HEAT SINK • CHASSIS MOUNT FUSE
• THREE CONDUCTOR POWER CORD except for RS-3A
• ONE YEAR WARRANTY • HADE IN U.SA
PEflFORMAirCE SPECfFICATIQNS
• INPUT VOLTAGE: 105-125 VAC
• OUTPUT VOLTAGE: 13.8 VDC + 0.05 volts
(I nrernally Adjustable: 11-15 VOC)
• RtPPLE Less than Srr^v peak to peak (full load A
low line}
• All units avaiaMe in 220 VAC mpu! voltage
(except tor SL-11A)
SLSE
* LOW PROFILE POWER SUPPLY
Colors Continuous
MODEL
SL-tIA
SL-11R
SL-11S
SL-11B-RA
gray Black QutylAmpsI
« » 7
7
t t 7
7
(Amps)
11
11
11
11
Size [IML
12
12
12
13
RS-L SERIES
POWER SUPPLIES WITH BUILT IN CtGARETTE LIGHTER RECEPTACLE
MODEL
RS-4L
RS-5L
ContfnutKJf
Duty lAmpal
3
4
ICS'
(Amps)
4
5
Size (mt
Shipping
WL m\
6
7
RM SERIES
MODEL RM-35M
• 19" RACK MOUNT POWER SUPPLIES
CoiilinuQus
MOOEL
RM-12A
RM-35A
RW-50A
mi-soiA
Separate Volt and Amp Meters
RM-12M 9
RM'35M 25
BW-50M 37
Bf^-60M 50
Duty lAmps)
%
25
37
50
ICS'
lAittpsI
12
50
55
12
35
50
55
Sizi UN)
HxWxD
5'rt X 19 X ev*
5 A X 19 X 12*1^
5'A X 19 X 12*^
7x19x121^
57- X 19 X 8%
5Vixl9x12*A
S^A X 19 X 12^
7 X 19 x 12'A
Shipping
WL llbsj
16
38
50
50
IS
3B
50
60
RS-A SERIES
MODEL RS-7A
MODEL
RS-3A
RS-4A
RS-5A
RS-7A
RS-7B
RS-10A
RS-12A
RS-12B
RS-20A
RS-35A
RS-50A
RS-70A
Colors
Cray Btacl
i
C{kntiAUOU£
Dity lAnpf )
2.5
3
4
5
5
7,5
9
9
16
25
37
57
ICS'
|AM|t)
3
4
5
7
7
10
12
12
m
35
50
70
SlZI (IN)
N X Wx D
3 X 4^4 X 5^
3^/4 X 5V? X 9
Vh X 6Vb X 7V4
3^A X 6 V? X 9
4X7V2 X 10^/4
4x7Vz X 10^/-!
4^/j X 8 X 9
4X7V2 X 10'/4
5 X 9 X 10V2
5x 11 X It
6x 13^^ X 11
6 X 13¥i X 12'i
Sllppiiil
MfL ilbt.j
4
5
7
9
10
11
13
13
IS
27
46
48
RS-M SERIES
MODEL RS'35M
MOOEL
Switeliatiie voil and Afip meter
RS'12M
Separate volt d/id Amp metefs
RS-20M
RS-35M
RS-50ht
RS-70M
Caiitiiioit
Dat| lAapi)
16
37
57
ICS'
(Anpt|
12
20
35
50
70
Sizi (IK)
i X W X D
4% X 8 X 9
5 X 9 X lOVi
5x 11 x11
6 X 13^ X 11
6 ^ i3y* X n%
SkJp^iil
Wl. \\\t.]
13
18
27
4€
48
VS-M AND VRM'M SERIES
SeparMe Volt and AfBp Meters • Output Voltage adjustable from 2- 15 volts • Current iimit adjustable from t .5 amps
to FuH LjQ9ii
MQoa
VS^12M
VS-20M
VS-35M
VS-50M
Ctitlll
Duty (Avfit)
@138VDC @10VDC @5VDC
9 5 2
16 9 4
2S 15 7
37 22 10
MODEL VS-35M
Variable rack mount power supplier
VRM35M 25 15
VRM-50M 37 22
7
10
ICS-
lAspil
@i3.ev
12
20
35
50
IS
50
II
X Wx D
4% X 8 X 9
5 X 9 X 10'^
5x11 X 11
6x 13^/4 X 11
5V4 X 19 X 121^
SVi X 19 X 12y*
Shlfpiil
Wt. (IbsJ
IS
20
^9
46
38
50
RSS SERIES
MODEL RS-12S
By lit in speaker
MODEL
RS-7S
RS'lOS
RS-12S
RS-20S
SL11S
Colors
Gray Black
Continiiiiui
Dity (Amm)
5
7J
9
16
7
ICS*
Aijii
7
10
12
m
11
Sizi {IN]
H X W X 0
4 X 7^i X 10^A
4 X 7^^ X 10^
4^ X 8 X 9
5 X 9 X 10^^
2^4 X 7^ 3C 9Vi
SblppllB
WL [fit I
10
12
13
10
12
'ICS— Inlermitteni ConirnunicatJofi Service (50% Duly Cycle 5m m on S min. olf)
aflCL£ IS ON READER SERVICE CARD
Number § on your Feedback cartJ
EMI/RFI Defense
Strategies for Hams
Keep those troublemaking signals out of your mobile installation!
by Donald Koehler N7IVIGT
You just finished the installation of a
brand-new VHF (or UHF) FM rig in ihe
car. You mm it on and gei a good VSVVR
and signal check. After cleaning up, your
significant other asks for a ride to the mall
on I he other side of lown. You start the car
and fire up the rig. Squuilch needs adjusting?
You crank it up and drive off. Repeater traf-
fic light? Friends complain you don't answer
calls? You may be the victim of RFl/EMI.
What is RFI/EMl? Radio Frequency In-
terference, also known as Electromagnetic
Incompatihility, h when one (or more) elec-
tronic or ciectfica! device affects or di>njpts
the normal operation of a "victim*^ system*
In the example above, the new radio was
victimized by weak, wideband noise from
digital automobile systems. This problem is
often exhibited by "loiit" calls or high
squelch settings.
This article will cover EMI/RFI defense
strategies, installation practices, and hazards
which may result from using certain
EMJ/RFl ctjres. Let's start by examinitig
three broad areas of action which can help
resolve EML
In tlie broadesi sense, EMI can be com-
bated by avoidance, aftenitation and/or iso-
lation. Any of these, or some combination of
the three, may be necessary^ to eliminate
EMI problems with insiahed equipment.
Avoidance
The least expensive of these strategies
may well be avoidance. Avoidance covers
several areas:
•Pre-iristallaiion checks of the area.
•Use of commercial software to fmd har-
monic "hits."
•Use of service bulletins.
♦Power levels appropriate for intended
communications.
Each one of tliese options offers some ad-
vantage for the ham or other installer. While
not listed in any particular order of impor-
tance, these areas should be the first you
turn to in installation planning and practice.
The use of a broadband, high-speed scan-
ner can go a long way toward identifying
potential EMI sources after a problem arises.
Use of the scanner prior to an installation
24 73 Amateur Radio Today • July, 1 994
can save time, money and possibly missed
emergency traffic. How do you use the scan-
ner in a pre-insialiaiion check?
I suggest using scanners in two ways.
First, load all of the common channel fre-
quencies you intend to use into the scanner.
Then, with the vehicle operating normally
(assuming a mobile installation), let the
scanner run. Listen for **hits" or EMI on
these loaded channels. The hit n\ay sound
like static, a whistle or a rough bu/z. Open
the hood, then caiefuily work the antenna
near the baiiery and any of the installed
"black boxes" (fuel injection computers,
etc). Do the same on the inside of the vehi-
cle. Run the heater or other accessories at
this time*
If no noise source appears, switch the
scanner to the search mode and set the
search limits to just above and bellow the
range of frequencies desired for use in the
installed equipment. Most modern scanners,
such as the ICOM miniature series and AOR
handhelds, cover 1 ()t) kHz to 2.0 GHz. They
are more than useful for ^his check. Note the
frequencies where the hits occur and see if
they are on, or are harmonically related to.
planned frequencies. More on this in the "In-
stallation Practices** section.
The use of commercial software to run
checks on installed or contemplated frequen-
cies may save a lot of grief up front. Har-
monic relationships may he hard to discern,
but the pruhlenis which crop up are real in-
deed. Most commercial software is powerful
enough to keep you out of trouble. Take a
minute to run these checks before instaUing
new equipment into systems or vehicles
where communications equipnicni is already
in use.
If you can take a few moments to look
through equipment service bulletins prior lo
installation,, you may save time. Look for
w^arnings on minimum equipment clear-
ances, grounding and power rcquiremenls,
antenna or power cabling restrictions and
other information which may impact on the
planned installation. Finally, use the least
amount of power necessar>' For the job. Mod-
em radio sets have compulcr-conlrolled-and
-set wideband frequency and power settings.
Never use more power than is called for in
the instalktion package. Besides being bad
practice, it can cause EMI or desense in
Photo A. Don'i leave power wire.\ nwuifig imsecured across the engine compartment! Poor
installation practices often lead to EMI/RFI problems.
1M
COMMUNICATIONS
ELECTRONICS INC.
Emergency Operations Center
IS'e're inirodudng ne\^^ Uniden Bearcat scan-
ners that are just what yon Ve been searching
for. Order your Bearcat scanner today.
25th Anniversary Special
■Save $25.00;
'on Uniden Bearcat® 8500XLT,
I
2500XLT, 890XLT, LRD9000W1 .
I
ICcldioleoiirlSch univeisacy wjth spectnl vavJQg&cn ihc ueiuinrrsBndl
ndir detector iuvmd in ihk sd. Thi i l tiuptin ju us[ be mc\ LhJf J wilh yam. I
Iprcpud order. Credil cards attd quiinlJly dUscounts aie excHudfid froKiH
ihisofTu, QHcr VMliJnttly on t>rdcnnin,i]cL] dli^lly UiCanunuAtcadODsl
BtecntKiiJcs liK., P.O. BoK ICH5 - 15c|iL 7:10694. Aim Arkir, Michigan
148 1 06-1 045 U.S.A. Coupon expiiies AuKUf^t 3 1 h 1 994. Linii t one cou pon W
\^i i[em. Coupon nuy not be used ift cocijuncLkm wjih my iKhcr uTrer.l
■ Vcui *lWr¥ pnrfiihil*d- Ci>up*^n m.av be ];)>hotac:ti|)tfsd «
miPi
[ JBadi^pcanners
Bearcat® 2500XLT-J
Lst price $649.95/CE price S359.95/SPECIAL
400 Channels- 20 Banks - Turbo Scan
Rotary tuner feature - Auto Store - Auto Sort
Si7*: 2 5/4" Wld€ % ll/r Deep X 7 1/2" High
/>tf-fn*w«7£^t*rfljfe* 25.0000 - 549 9950, 7600000 - 825.9950,
e'*9.0125 - S^.995€. 8^.0125 - 1,300.0000 MHl
Sipal imjelligence experts, public safety agendcs and
people with inq^jinng minds that want lo know, have
isked 115 for a world dass handheld scanner that can
intercepi jitst about any radio transniissiofi. Itie new
B^ifcat 250OXLT has what you want You can pro|rani
frequencies such as police, fife, emergency, race cars,
nisirine, miliiary aircraft, weather^ and other broadcasts
into 20 banks of 20 channels each. Tlie new rotary tuner
feature enables rapid and easy selection of channels and
frequencies. With the AUTO STORE feamrt;, you can
automaticalfy program any channel You can also scan all
400 channels at 1 00 channeb per^^cond speed because
the Bearcat 2500XLT has TURBO SCAN biultin. To make
this scanner even better, the BC2500XLThas AUTOSORT
- an aulomatic frequency sorting feature for faster
scanning iniihin each bank. Order your scanner from CH.
For more information on Bearcat radio scanners or to
join the Bearcat Radio CEub, call Mr. Scanner at 1-800-
425-1331. To order any Bearcat radio product from
Comrminicatjons Electromcs Inc. caM 1-800-USA-SCAN,
Great; Deals on
Bearcat 8500XLT-J base/mobile $369 95
Bearcat 890XLT-J base/mobUe „$244.95
Bearcat 2500XLT-J handheld $33995
Sportcat 150^J handheld $199^95
Bearcat 760XLT J base/mobile .. $ 19995
Bearcat 700A-J info mobile ...$l49 95
Bearcat 560XUJ base/mobile .„. $84.95
Bearcat 220XLT-J handheld $229.95
Bearcat 200XLT-J handheld , $199 95
Bearcat HSXLTJ base/WX alert, $88.95
Bearcat 120XLT-J handheld $159-95
Bearcat BCT2-J info mobile ...,„. $139 95
NEW! RELM® WHSl 50-J
Ust price $48L67/CE price S359<95/SPEaAL
16 Chftjuel '^ 5 Wan VllF fcanniiiig iranEicetver
Stec; IAS' Wide I t JS" Ekep i 6.4" Hiih
Frtmienor' TSngt:liSGOQ ^ ; 74000 MHz conUnMOtts cof-ffage.
wm aiso iroinl / 44 000-14^000 MHt uiih reduced ^fanrui nce.
The RELM WIES 1 50 is our taoA popakr pfogramniibk fht WiXU
16 dunud h^dheid tnmceh^r witti built-in CTCSS. whtcb mrf
be progrunDied for iiif 39 stjuidard ^A [ones. The full fundkMi,
DTMF compaiible ltF^T>ad ilso alkiu^ fof DTMF Encod€,'I>ccwle
ind prograin Enable ANI. Wei^hJEigonly ]5o oz. Jt featares dealer
pmBranmiable syntlHiSizcid freqncnd^ either simplex or half
dupleic in both 5,0 and 6.25 KHi. incrcincnts, OUicr features
Include scan list, priority chiuinel, sc led able scan delay, seledable
S wall/ 1 wan pow^r Itvels, liquid cryNiiJ display, time oui timer
and much more. When you order iht WiiSlSO from Comnionicar
^m ElectfOfiia inc. you'll gel a compete par Jtage de»i incjudiflg
antemii, baiteiy, belt clip and oscr opcfatiog in£trtKil4>ru. Otber
Xifswnei arejv-^ilabJe, A leaiber carrrti^ case with swivel beh
loop part #LCWflS ts 549 ?5: rapid chir|Ee bttierf chir^tr. pan
* wtWHS is 569 95; spMier/miawpbone, part *SMWTi S ts J 5 4.9>;
ciira nurad Iraitery pack, pan 'iFOO? Is 159 9> "^ '^dfo
ii^chnidan mttaiainini year radio system mtisf O'fder progniD'
inlng instraoions pan *PI150 for $18.00 lo activate this radio.
Bearcat® 8500XLTJ
list price $689-95/CE price $369.95/SPEClAL
500 Channels * 20 banks * Alphanumeric dfjtpl ay
Turbo Scan * VFO Control * Priority channels
Auto Store - Auto RecoFdtng * Reception counter
Frequency step resolution 5, 11*5, 25 & 50 KBz.
Size: 10-1/2" Hide x Tl/l*- De^ x 3-3/8" High
frequency Corerage:^
25,000 ' 28.995 MH*. (AM), 29-000 - 54 OOO MHt (NFM)*
54.000 - 71.995 MHt (TFM), 72.000 75.995 MHi. (hTM).
76.000 ' 107.995 mt (WFM). 108.000 - 156.995 MHzl (.W
137.000 - 173.99^ MHi (Wra), 174.000- 215995 MHl fWFM),
216.000 - 224.995 MtU. (NFM), 225 000 - 399-995 Mill. (AM)
lOaOOO - 511.995 MIlL (OTM), 512.000-549995 MIfL (¥FM)
76aOOO - 823.9875 mi (hfFM), 849.01 25 - 866.9875 MHi (NFM)
B9i0125 - 1,300.000 Wlli. (NFM).
The new Bearcat SSOOXLT ghes you pure scatmlng satisfaction
with aj^azing features liire T^riio Scan. This Jightning-fa.'St tech-
nology fea curing a iflpk comreisiofl RJ system, enables Untden's
b^t scani^ef to scm and search up to 1 00 dtaoiiek per ^cond
Because the ^eqtiency coverage is so lar^, a verf fit scajmifi^
sfsteiD is essential to keep up ^ith (he actioiL Oilier feamies
include If D Coafroi - fi^amblie Trequcncy Osdnaiof) which
allows j'ou lo adju?;! iht large miar)' loner lo select the desired
frequt-ncy or channel. Counter MspUiy - Lets yoi] count ajid
rccr>rd each channi'l while scanning. Amio Store - Aulojnatl^
odly stones all active freguendes within the spedficd bank(s).
Auto Recording - This feature leb you record channel activity
from the scanner onto a tape recorder. You can even get an
optional CTCSS Titne iloarrf [Continuous Tone Control Squeldi
System) which allows the squelch lo be broken during scanning
only when a correct CTCSS tone is received. 2Q ^nks - Each
bank contains 25 channels, useful for siom| simikr frequencies
in order to mainiain faster 5Gtanli}| chides. For roaximuiD
scannini enpoyment. ordef the following optional acceasofk^
FSOOt Qgarette lighter power cord for temporary operaimn
from your vehicle's dgareite hghier $R95; PSp02 DC power
cord ■ cnahjcs permanent operation from your ^ehitki's fuse box
J 14.95: MBOOl Mobile mountinjj bracket $ 14,95;BC005 CTCSS
Tone Board $5195; EX71I Estemal speaker with mounting
bracicct & 10 feet of cable with plug attached $19.95. The
BCaSOOXlT comes with AC adapter, telescopic antenna^ owner's
manual and one year linilied warranty from Uniden. Order your
SCB500XLT from Communkationj Electronics Inc. today.
CI
mj^s}
< - I— )
^sss
OiZlO
EJOO
ODD
The Uniden GMRlOO Is a handheM GMRS UHF 2"Way nidio
tnmscelver thillHls these eight frequcndi^ instaikd: 462, 5 50»
4^2.725. 462.5875. 462.61 25. 462.6375, 462,675, 463.6625
and 462 6875 MHi. This one watt r^io comes ftith flexible
T^abiT antenna, rediargeabk? oi-c»i binay, AC idapter/
charger, beh dtp, F.C.C. hcens^ applicaUoti and loore.
Cobra 2000GUJ SSB Deluxe CB Base $389.95
Uniden GMRIOOJ GMRS Handheld $159 95
Uniden WASHINGTON-J SSB CB Base $189.95
Uniden GRANTXLJ SSB CB Mobile „....$ 1 39.?5
Uniden PR0538W-J CB & Weather. $59^95
CtRCLE 3S6 ON READEF4 SERVICE CARD
??!'?'f?!5!i!PI^^
KDH II J oitra conput hdodlKkl wlcklMiid rccdrer .
)COM AHTOO&j super widelawl (tiseooe type mieiui
Gntndig Satettt ~0OJ nrtafclc wMh 5U lOEUOiy lAC
Gmadlg Yacht Bey 40&JI difttil poflabk fkwtwive _
Grwtdj^ Yidil Boy 250j portibK ibwtvsic _
•469.95
- 19995
i3S9,95
119995
1139 95
--t79JS
1149^5
$in|fiii hlS^^^ vJhrt cf^mpxi "Hi memory shomntve
Suif^nn AlS^O^J ultra cDixqnct i5 meniory thoftn^t^'f ,^
Smie^ui A1^6o6P:} sboftn rve irith anLenni & AC adiptef . Si 69.9$
Sifigc« AlSBOfrJI pcff1*bk! 20 iBrainnf sh«ftwi:Tie ►***««„ I69-9S
Ssngrxn AT!;S03A-j portibk with SSB reccpikm &. AC adaptrr . I ! 59.9$
Smngcin ATSSOSJ portilile 45 nmiDory sixtrmive , 1159.?^
$in|ean ATSil^) pcrtsibic uriihout casHitc reccrder .f I89^?S
5,in[i<:im ATsSIiSCS;! with aissHMi recorder 1209.95
Sang^an AJSTWJJ portable shortwave anrenn* I99S
H%
PubUc stitvi igoides itiponding lo baLTJurdous niiEeriah uKsdert;^
htve acmrale, upK^dale w^aiher uifontiitiOfi The I>^^i$
Monitor 11 is our lop-of-Lhe4Jne weatlver statkMi wtuch
combines essential wieathrr moniiofiog functions into otk incnidLble
package. Glance at the display, juid see wind direction aiKi wind
speed on die compass rose. Check the bsuomeiric ircml arrow to ice
if the pressure is rising or filling. Our p;ickiigi^ deal includes the new
Idgh resolution 1/100 Inch rain collector part #7R52J, and the
exiemal lemperarure/hiimldiiy sensor, pan #7*5 9-J T)»e pick age
deal l5ord<^r#D.%Vl J kit S524.95 plus $15.00 Bhipping. If you have
a personal comptitef, when ycm order the opdonal ^ejthi rlink
cooputer sofrv^ for $ 149 95, yoo'U haw i powerful cooipiiteTtEtti
wcatbcr station at an tnord^le prke. For the IBM PC or eqatvilent
ordct p*n #7 S62J. For Apple Mac Fhts. or highcf iodudiDg Qmdra
or PowwBool, order p$n #7g64^j.
OHier nWt stuff I
Vnid^ii IW9200-J 9<W Mlir Z line cordless phnop „.
VnMi-n mf9ltm 900 Milt 1 Me fflJrdieiS \ihmr
CQf»r J t^^'910'} 900 MHz. spread spfctnim eordlcss phone
ICOM GP22 J huidiieliJ ^liihi) posJIiooiiif sysUiffl
WR200J wtiith^r raJio nlih stonm akrt , ~
HEIM WHS] !^ j VHF tiajnUieid 5 imi, 1< di ittmaivti .
MIM tll2S6KBJ VHF 25 wall jynih«^ed ittsaatfa
bngnr iQ295Q-S X5 wan lO inner bim radio .
tamicr IO2970J 100 wui 10 mttti him mlta
Pirej Pt^)i^ to THkHMad tadio Iff (BS
PQll J Poface CaD lor in'. HE, HK Mi KY, tl, VT
P0L2J FoftceCan for DE. MD. Nl. FA .
H>i3-|FDhteCaiJf{>rMidiJpJiftOtiio ^
P0L4 J Pfilice CaU lor iU IN. SCY, TI
IliHIII lllhlllllll
P0L5J H'itcf Can for lA, JLS, MN, HO, Ml, ND, SO
?0\Ja-S Pfrbce CiU for DC, FU CA, NC, PR, SC VA. WV
POL?] falkl Call for Al*. AB. LA, MS, OK, TO, TJt
POL&J PuUre Call Iqi AZ, CO, ID, MT, NM, NV, IJT, WV
P019 J Follce CaJI for CalifttmM, Oregon & Wa^hiiigtoa .^.....
LUSAMMMQT'J ii)!i|7)Rt mount sc^ui anienna w/Mfltorola plug
USAHklPl-l m^oei mouni tcan antenna with PLl^9 coniwctDr ..
IJSAMMB^fOJ maputt hkhjhI vajmer znteniu w/ K.NC caonectDr
USAKJ VHF •aoa^/MlF tran^aitting tntnrna fi2%9 mmwciDr
USASGMBKf^ 0aa$. momvL loiruvr tniaua mib B.NC coam^K
USASCMMj pgi MOt aCifuatf imrnna *'«h Motorola jiact
124995
1699.95
. I39.95
tJJ9.95
S189-95
SZ44.95
U69.95
ll6?.95
-(1095
J5.95
15.95
15 95
1595
f5.?5
«.tS,95
.. %SSS
.. »5.95
..*5.95
12995
11995
12995
$2995
12995
129-95
Bu^^pth confidence]
It's easy to order from CEI. Mail orders lO: Communic*
tions Electronics Inc., Emergency OperaUons Center, P.O. Box
J 045, Ann Arbor, Michigan 48106 U.S.A. Add Jl 5-00 per
radli> for U.P.S. ground shipping and handling in the conti-
nental USA unkss oihenvise stated. Add $8.00 shipping for
all accessories and pnblkations. Add $8.00 shipping per
antenna. For Canada. Puerto Rico, Haw;ui, Alaska^ P.O. Box,
or APO/FPO delr^Tiy, shipping cha/ges are two times conii-
nenial lj.S. rites. Midilgan rfsklents add siatc sales tai. No
(X)D's 1 0% sarchar^e for ne t J 0 billing to qualified accounB.
Ail sales ire subject to availability, acceptance ar>d veftficir
lion. Prices, lenns aiMl spedfiotfons are subject to diange
without notice. We welcome vour Discover ^ Visa, Amcfkan
Express or MasterCard. Call i-80(>USA'SCAN to order toll-
free. Call 3 1 3-996^B^ If outside the U.S.A. FAX anytime, dial
JI 3-663 8B88. For tedinJcol assistance to solve your
communications problem, call I he CominiinicatiDns
ilectronlcs technical supoorl botliiie for $2.00 per
minute at 1 -900-5 55'SCAA. Order your new elecironk
equipment from Communlcadons Electronia Inc. today.
For credit card orders call
ISOaUSA-SCAN
Communications Electronics Inc.
Emergency Operations Center
P.O Box 1045. Ann Arbor. Michisan 4810^1045 USA.
For btformatlon caU 5 1 5 996-gS«8 or FAX 5 13^^'SS8S
I
Fhoia Br Using a scanner wili help pinpoint problem ^* black boxes."
orher installed equIpmenL In this case, the
old saying *1f a little is good, gobs is great*'
doesn't hold true.
AtlenualioD
The issue of power output brings us lo ibe
nexi of ihe major strategies, attenuiiiion.
When EMI problems arise, one of the main
effons taken by experienced technicians is
to attenuate the inierfering signal This at-
tenuation may taki^ numy forms. The nn>sl
typical is using filters, both RP and IF. You
may not nonnally consider cavity fihers,
cfysiaJ fihc^^ and alternate siting of antennas
to be a form of aitenuaiion — but that's what
(hey do to the unwanted signal. One filter
strategy often overlooked is using ferrite
beads on power leads and, occasionally, on
RF cables. Finally, bypass capacitors on
power leads or power sources offer a low
impedance path to ground for EMI signals.
Isolation
The third sifaieev is isolation, Bv the use
of shielding, bonding, and AC or DC filter-
ing, the communication equipment can be
isolated from EMI signals. The shielding
may take the form of conductive foils, tubes
made of conductive or attenuating material,
conductive caulks and conductive tapes.
When ysing these conductive shields, ex-
treme care must be taken to ensure the mate-
rial will not come loose and short out other
equipment. The idea of the shielding is to
conduct the EMI signal away from your
equipment and to provide a low impedance
path to ground. Another way to do this is to
ensure that all equipment is properly bonded
to grt)und. New vehicles make extensive use
of plastics and exposed metal that often have
been coated with anti-rust compounds.
Bonding can take several different forms.
Use of conductive strapping, lyinL» together
both radio equipment and mounts to the ve-
hicle frame, i^ a good, low-cost start. Further
work lo tie the vehicle body^ frame and neg-
ative battery terminals into one circuit may
yield results to reduce background noise,
When running power leads, make the run as
A NO-RADIAL VERTICAL
THAT COVERS 80 OR 75 METERS?
THERE'S ONE NOW!
No, we won't insult your intdltigence by telling you that tfs a
"halfwave" or that ANY vertical will operate more efficiently without a
good radial system than with one; it certainly won't! If you want
expensive fairy tales talk to our cOfTipetitors! If. however, you've no
room for even the smallest radial system just install the most efficient
multiband vertical in the business, the HF9V-X, over our counterpoise
kit. You'll not only save a tidy sum but you'll work DX that the shorter
and more lossy no-radial "halfwaves" can't touch because both the
HF6V-X and HF9V-X use longer active element lengths for higher
radiation resistance and greater efficiency on more bands than any of
the so-called halfwaves. Ask for our free brochure for complete specs
on all Butternut models and receive technical note DLS-1 ''Difty Little
Secrets from the Antenna Designer's Notebook") that shows you how
to caiculate the probable efficiency of any vertical antenna using the
manufacturer's own specs so you won't have to learn the truth the
hard way!
Model HF9V"X (shown to the left) for 80/75, W, 30, 20,
17, 15, 12, 10 and 6 meters.
Model CPX counterpofse kit for Butternut models
HFSV-X, HF6V. and HF6V-X; substitutes for ground or
elevated radrals. Self-supporting tubing bolts onto
base of antenna. Mast not provided.
BUHERWUT ELECTRONICS CO.
P.O. Box 1234, OlmitO. TX 78575 (210) 350-5711
Why Take
Chances?
EXPEOrTED ORDER
SERVICE FOR:
General Communication • Industry • Marine VHP
Scannefs • Amateur Bands • Microprocessor
Experimental
Get your FREE 1994 Catafog!
CALL TOLL FREE: 1'80(hJAN'XTAL
P.O, BOX 60017 * Fort Myers, Florida 33906
(813)936-2397
CIRCLE 240 ON READER SERVICE CARD
26 73 Amateur Radio Today • July, 1 994
Explore The World of Quorum Wefax
Wefax Explorer
Iniegrated Wefax / APT Receiver and Scan
Converter with Qfax soflware.
$695.00 complete
shipping and taxes not included
The Best Price I Performance. Period!
Construct a Wefax / APT reception system from individual component receivers, scan converters and image processing software
and you'U spend more money for fewer features, poorer perfonmmce, no automation and a jungle of wires. With the Wefax
Explorer, simply connect an antenna and a few mouse clicks later you Ve receiving the highest quality images possible. The
Explorer is hacked by a 1 year Itmiied warranty and the extensive experience of tlic leading Wefax hardware manufacturer.
Quorum equipment is used by virtually all wefax suppliers in worldwide amateur, commercial and military systems.
i"^ i ■■■■ I ^..
Integrated Satellite visibUity pre-
diction with automatic capture far
up to 8 satellites simultaneously
A utomatic time and ephemeris
Stamping for navigation
2 7 day programmable schedulers
Automatic dtf^italgain lock in
ALI^ modes, I'LL clocking
QFAX Features
I GOES / Meteosat Wefax Reception
I NOAA / Meteor APT Reception
I HF Nafax Reception
I Dual RF ports for geosync and polar
reception under software control
integrated preatnp and down con-
verter power inserters
SO user definable configurations
Software controlled receiver with 2
UHFf 10 VHF memories and scan
On board audio amplifier and
speaker with software controlled vol-
umcj squelch and mute
Autotnatic Unattended Animation
works continuously
8 bit data for up to 256 gray levels
View at up to 1280 x 1024 256 color
Use TIFF, GIF or PCX fde formats
and convert to BMP, JPEG, EPS
and binary
Contrast, Brightness^ 3D effect.
Sharpen^ Smooth^ Noise, MistO'^
grams and other image processing
Ephemeris based NOAA APT navi-
gation With geo-political and Lat-
Lon overlays
NOAA Tools show satellite path,
Lat-Lon of cursor, distance and
bearing to reference point
Automatic Temperature Calibration
Color Palettes and NOAA curves
Quorum Communications, Inc. fa\(214) 915-o27(»
8304 Esters Blvd. - Suite 850 - Irvin", Texas 75063 (214) 915-0256 BBS (214) •>15-0346
'
I
CIRCLE 257 ON READEFl SERVICE CARD
Fhoio C. Using a svanucr to di'tevmine ihe best mure for power leads saves time ami trouble.
short as possible using proper gauge wire.
AC and E>C fUters such as chokes and ca-
pacitors will help lo keep "hash" or wide*
band noise out of equipment. I have had
luck with additional filtering gaitied from
ferrite beads placed over the power leads*
Secure these ferrite beads with glue or tie-
wraps to avoid dan^tage to the bead caused
by movement. Now let's lie this information
into the Installation process*
Installation Practices
When first planning the installation of
communicaiions equipment in a vehicle,
take a moment to "sweep*' the area with a
scanner. This should show potential EMI
sources, T\ pical areas are near vehicle black
boxes, digital dashes and other displays with
multiplex drivers. Once any EMI sources are
identified, route power and RF cables away
from the source. If the cable royting doesn't
allow for avoidance, the use of shielding
may be required,
Fie.vible, conductive tapes, conductive
caulks or foils can be uh^cd lo cover the
cabling which runs by the source. Short
lengths of cable requiring this EMI cover
caji he easily fabricated in the Held. Ground-
ing of this cover material is usuany not
necessary. Each application will be unique,
though. Common-sense precautions are
essential when using conductive materi-
als around power sources. Covering conduc-
tive materials with insulating taj>e will not
impair the shielding properties of the ma-
terial
Taking the time to bond the radio, the
mount and the vehicle body together can
eliminate sources of wideband noise. When
installing mobile computing equipment, this
step may become even more important as
this equipment can often generate large
amounts of wideband digital noise. Use care
to bond the interconnecting cables and con-
nectors. Ensure solid ground paths on the
vehicle by sanding the area around the con-
necting fastener. The use of modern anti-
rust compounds can impair or raise the
impedance of the ground path. To protect
the ground connection and fastener, the use
of conductive caulks or grease is recom-
mended- Use of small an-sounis of conduc-
tive caulks under mount ''fingers" may im-
prove grounding of blind mount antennas
when insMling equipment in off-road vehi-
cles or in humid climates.
As always^ when installing equipment in
off-road vehicles, lake the lime lo read
both equipment and vehicle technical data.
I have had good luck with these rule-of-
ihumb procedures when installing radio
equipment in vehicles as diverse as air-
craft t^ueling trucks, snowplows, fork-
lifts and fire trucks. If you have quesiiuns,
talk to your vehicle service personnel or
dealer.
Avoiding Hazards
Even the besi-planned installation can
generate hazardous conditions. Let's look ai
some of those conditions*
When using conductive materials for at-
tenuation or shielding, be carefuH These
materials may become conductors of oppor-
tunity or pan of sneak circuits not protected
by fuses. To guard against this hazard, 1
fuse both positive and negative power leads
as close to the battery as possible. Foils
used for shielding can cause heat buildup.
Before using foil as shielding material, en-
sure thai doing so will not violate the vehi-
cle's warrantv. After installation, check all
vehicle systems with the installed equip-
ment up and transmitting. Imagine how em-
barrassing (and dangerous) it could be if
your transmitter caused the vehicle anti-
locking brake or fuel injection system to
fail, X^Tule these types of problems are rare,
it on!y takes a moment to check EMI inter-
actions with the vehicle's systems after the
msiallaiion is complete.
After alL if you didn't install the vehicle
alarm, cellular phone or stereo equipment,
you must be sure that these common sys-
tems don't cause problems for your new
mobile rig. Take the time to use some of
these strategies, and enjoy your EMI -free
mobile operations*
Installation Hints
Good installation practices vM go a long way toward preventing possible EMI problems.
Try these tricks — they work well for commercial and amateur Installations:
■Replace the battery terminal clamp with a new, tight-filting clamp. Use the kind with a
new ^'generator' lead cast into the damp. Pull the DC buss line power from this clamp.
'Use a multiconnect or ijarrier'^ block for your DC buss. This makes it easier to place by-
pass capacitofs, if necessary.
•Don't splice wires^ il at all possible. Each joint is a possible corrosion spot that could
cause problems,
•Don't install the radio next to or under heater vents or, on older cars, near the heater or
wiper motors.
QUICK. EASY, & COMPACT
Ffash cards 'NOVICE Ihru EXTRA" theorv Kev words
undafljned Over 4000 sets m use! For beginrkor. OMs,
XYL5&k«te.
'
rr
Ortier Today i
IfOVCE
T1CWC3AH
OCN0t*L
^mZ T^» VIS STU DY CARDS
jwinew u.m P.O. BOX 17377
CLiiB DI5CDUHT9 HAITI ES BURG, MS 3S404
\
CIRCLE 1W ON READER SERVICE CARD
mpaiief c»n Ihc *if 'roufMl ihc clock w powers your ini>* HF stotioii \
60 hr» M muftlh. Corrtml trircUll £)K«d» eha/gt, pfOtetlA pd celli &
(dOt)373-$425 n^^^ ^^^^ ^^^^ ut^4605
CIRCLE 33€ on READER SERVICE CARD
PAY TV AND SATELLITE DESCRAM8UNG 1994
NEW,.., free BBS with sub lo An^rican Hacker. ..New Titles
Pof TV afrd S^eiiiti D«cr.anb4trtg 1^^ —zi'-^i 'ai«i\ <:^X^ bOs and IBldlfr
btv Sc^iE-T^cj. '.y-'-j-.i DypatiHv &m Mes lulilL f£M%. ?'; O-jr btH |d.
S7W ^n^iujes fisSi HKkv VMh AI t^i lixwi SlS 9£ CKh 3&4 » or
S-ES2M Amcflcin Hadur mom^ nc* ^c^^dgA cabis, satefist conitK^er^.
Tifit Eurepean Senm^ing SystMni. 480 pages. OS'S® naw oB^oq |1
SCRAMBLING MEIflfS
1S52 H^rtel Ave.. M153, Buffalo, NY 1421fi
VoJCQ^ AX/BOS- 7 1«.Q74.?i»Q COO- s ara OK. Add S6
CIRCLE 3e ON READER SERVICE CARD
28 73 Amateur Radio Today • July, 1 994
m I BIJLLETIN i
July. 1994
182 North Maple
P.O. Box 73
Watertown, SD 57201
The wkai you say is w^t you g£i ^taU'
INC
AMATEUR CENTER
oM^t ^teat
HOURS: MON. - FRI. 9-5 p.m.^
SAT. B-1 p,m.
CLOSED SUNDAYS/HOLIDAYS
^
V/M
Write for our
current bulletin
and used
equipment list.
SELECTION
Hoppy 4th of July I
from AH the Gong |
Stan
WOiT
J{fn
We0MJY
Darrell
WO0GDF
Jaacm
KBOiUS
Marty
Tim
KBOIOW
WDOFKC
David
KA0JDN
Slovo
Lori«
Sharon
Shipping
Bookkeoprng
Receptionist
Lto R: Jim SiTiith, President,
with Stan Burghardt^ founder.
J I I 1 «> !■ I ♦ »— -4 H ■« -
aM)
TdaaJ - ll ■ J kit * 1
S%0
■ i| ^-rA * l-|>#-va k .. J . 1-^1
I . I _- ■'^■*i-T-rL*_-^_^J*A'' . ' .* . a^ i ' I * : L t _"i •■_* -^
_l,|.*jiyy,ri»i(!!_
■ - " • _'.«.• S.t- -t I - - ^ - - J i. - .
upott;
able to place one s complete confidence in for all your ham
m^o |j.eed§, esp. rejgting to Burghardt Araateur Q§ntej.
■,!-■-'.'-• '..*.^- i^---
■-v.^^^ ,'.' '.'i Vi .-I'.vr'
. ^ 1 1 till
- 1 ■ - 1 1- J
. J -'I I 6-|?B 4 J - I I. J p. .
CALL US TODAY!
reliable staff — most of
our staff has been here at least
15 years* Stan's been here for
57 years.
reliable service — fully
authorized Iconi, Yaesu and
Kenwood service center.
!
I
I
I
I
1
Sales Order Line
800-927-HAM 1 (4261
For Teehnical & Info.
(605) 886-7314
FAX (605)886-3444
FAX PRODUCT INFO
(605) 886-6914
CLIP & SAVE •
)
T
I
I
I
I
Call US TODAY!
reliable equipment —
we have all the brands you
want,
reliable used gear —
fully reconditioned and guar-
anteed. We take trades. If we
don*t have what you want, get
on our want list.
73 Review
Number 7 on yiMir Feedback card
by Michael Bryce WB8VGE
Engineering's
S 4 S Engineering
14102 Brown Rd
SmithsburgMD 21783
Telephone: (301) 416-0661;
Fax:(301)416-0963
Price Class: Kit— S49.9S:
As^fnbled and tested— S69.95;
4Kifgit add-on kit— $16.95.
Frequency Counter Kit
Now you can count frequencies 'til your heart's content.
When S 3i S Engineering sent me this fre-
quency counter kit for review, gosh, did
li bring back memories. My first home-brew
frequency counter came to fife In the mid-
70s. Ofi, those were the days! Johnny Car-
son was king of fate-night TV, the Bay City
Rollers were rocking Top 40 radio, and the
USSR and the USA were sneering at each
other. All you needed for a frequency counter
back then was a VW bus full of TTL logic
chips, 15 pounds of solder, yards of multicol-
ored wire and several PC boards to hold ev-
erything together Any ol' 5 volt supply at 27
amps was all it took to fire her up. On a good
day, with the wind blowing just rights you
might be able to read 10 MHz. Provided you
handpicked the first gate chip, a 74HS90,
The S & S Engineering Counter Kit
We've come a long way since my first
home-brew frequency counter. S & S Engi-
neering now has available a frequency
counter kit for under $50 bucks. Even on its
worst day. Its top end \s 75 MHz, Why, with
the exception of two wires for ttie battery, ev-
eryltiing Is on one PC board. Best of all. the
entire counter can be run by a single 9 vo!l
battery.
The display is a large 1" LCD giving you
four-digit resolution. This can be expanded to
eight digits later if you wish. The upgrade is
simple, easy and, most of all» cheap— less
than $20. 1 highly recommend you get the up-
grade to eight digits.
The S & S Engineering counter kit consists
of a high quality double-sided PC board with
plated-through holes. The PC board has the
parts layout sifk-screened on It, and i£ has
been laid out so the top third of the boand, tfie
portion holding the LCDs, can b© cut from the
logic section. This way. you can mount the
display away from the logic section for a cus-
tom Installation. There are only 12 wires
needed between the display and logic. Rit>
bon cable would be idea! for this. I did not
separate the two for this review.
TTie kit does not come with a cabinet; that
part is left up to the builder. There are four
metal standoffs supplied to raise the PC
board up. This way, you can leave it as is and
just use the bare circuit without a box.
30 73 Amateur Radh Today • July, 1 994
As with all of the S & S Engineering kits,
the part quality is first-rate. No "hamfest spe-
cial" parts or surplus goodies are in this kit.
As complex as a frequency counter is, most
of the work is done by specialized chips. This
reduces the overall part count of the kxt to just
a handful of IC chips. All the tCs come in
static-protective packaging. The kit includes
everything you need, including a 9 volt bat-
tery snap. Sorry, the battery is not included.
Assembly
Assembly is very straightfonvard: Vou start
with the resistors, move on to the capacitors,
and finish up with the transistors. The IGs are
installed next. Although IC sockets are not
provided with the kit, you should use them.
The IC sockets are cheap insurance in case
you solder a chip in backwards or install the
wrong chip in the right hole. Unsoldering an
IC from a doubte*sided PC boafd with plated-
through holes is not for the weak-at-heart.
The kit requires six 14'pin sockets and one
16-pin socket. There is one 40-pin chip under
the LCD display that you can't use a socket
on. It would make the chip too tall, and make
it impossible to mount the LCDs on the
board.
A NEW COIMCEPT
IN HF TRANSCEIVER DESIGN
FROM A NEW COMPANY
» poieio IRJ
RANSoervBR
ri^ «I7^
«* »■= «*
^f^
pBicomm
im
.09
Patent
Pending
Patcomm Corporation'^
introduces the PC- 1610" a ful! featured HF trans-
ceiver with built-in keyboard interface. Plug a stan-
dard IBM XT* compatible keyboard Into a PC-1610
and instantly enjoy keyboard CW, RTr/ (BAUDOT
and ASCII) data communications. Incoming morse
& RTTY data is decoded and displayed on the built-
in LCD display. The PC-1610 offers the following
features:
■ Built-in XT keyboard interface (keyboard
optional)
■ 160-10M ham band coverage
■ USB/LSB/CW/FSK modes
■ 75W output power
■ Built in digital power/SWR meter
■ DDS VFO with 1 Hz step size
■ Selectable variable speed/fixed 1 GHz step
VFO tuning
■ Built-in 24hr dock
■ 90 tunable memories
■ 1 scratchpad memory
■ 9 (256 character) keyboard data buffers
■ Built-in 5-75 wpm IAMBIC keyer
■ Built-in 2.4KHZ, 1 ,8KHz, 500Hz. 200 Hz &
RTTY filters
■ Notch filter
■ Select 1 of 3 antennas from front panel
SpecrtiGatlons are subject to change without notice,
' fBM XT is a registered trademark of the IBM Corporation*
Basic display lets you know
exactly where you are.
n035lO-T
n035fO-R
GS30
i IL.tL.iLj
Standard Display
shows RX/TX VFO
freq's, time and
current memory
Send & Receive in:
CW / RTTY{BAUDOT) / ASCII
Incoming data
Outgoing data
appears here
Store up to nine 256
character messages.
N.035lO'T
LJ
3> cnnnED nsQ
Messages can be:
edited, sent &
appended to out-
going message
Format & Edit
stored MSG's here
PC-1610 =
HF XCVR
The PC-1 61 0 Performs the
functions of an HF Trans-
ceiver, Computer, Data
Controller and Control
Software all in one package.
DATA CNTLR
The PC-IBIO has too many features to adequately describe in one ad.
call or write for a detailed brochure— Major Credit Cards Accepted.
Designed and manufactured in the U.S.A.
Phone: (51 6J 862-6512 ■ Fax: (516) 862-6529
7 Flowerfield Ml 00, St. James NY 11780
CIRCLE 321 ON READER SERVICE CAM)
As with most counters, you can select
the gate time of the counter. You can select
between 10k, Ik, 100, 10, or 1 Hertz reso-
lution. A multi-poie rotary switch mounted
directly on the PC board selects the gate
time. There are no interconnecting wires
to worry atxjut. But, this switch might prove
a pain in the butt if you want to mount
the logic board separate from the display^
Some forward-thinking would be in order
before applying soider to the switch termi-
nals.
Assembly went along without a hint of
trouble. The instructions are a bit thin, but
they get the ]ob done. All in all, ft took me
about two hours of work to complete the kit,
even with extra-long breaks for Oreo cook-
ies and Diet Coke. I installed the extra LCD
and Its driver chip, too.
Testing the counter ts about as simple
as you can get. Apply power, and connect
the input of the counter to a test point on the
PC board. If everything went in as it should,
you'll see 10 MHz on the display. A trimmer
capacitor on the PC board calibrates the
counter to either WWV or a known 10 MHz
standard.
Operation
The counter will operate on a fresh 9 woJt
battery for several hours. There is no power
switch. For use on your workbench, just about
any quality source of power will work. Watch
out for those wall-wart power supplies! Many
are nothing more than one diode with very
ftttle filtering. The input supply voitage is
between 7 and 15 volts DC. The counter re-
quires about 50*60 m A,
Set the rotary switch to select the gate time
and thus the amount of resolution you require.
The longer the gate time, the better the reso-
lution of the frequency displayed. The longest
gale time is atraut four seconds to update the
display. That's rtl
Since the S fit S Engineering kit Is so se^f-
contained, it opens up a new way of seeing
things. I've always used a frequency counter
to spot trouble. They make great sniffers of
RF. The S & S Engineering kit has more than
enough sensitivity to sniff out weak signals. In
fact, it could read the lest point just by holding
a wire near the input pin.
I found a particularly useful task for the fre-
quency counter; Reading the VFO of a direct
conversion transceiver You can also use the
counter to display your operating frequency in
a superhet receiver, too. In fact, there are
some suggestions on how this may be accom-
plished in the assembly manual Since you
don't require the longer gate times, and thus
the four extra displays, the standard four-digit
unit works best. I would bypass the gate
switch with jumper wires. By using this
counter, you can add an LCD frequency
counter to your latest home-brew project.
The t-ast Page
This project is simple enough for a be-
ginner to handle. It would be best if you have
some idea of how to solder, what end of a
diode is what and, of course, the proper
installation of IC chips. Except for the calibra-
tion adjustment, there's nothing to touch. If
you assemble it correctly, it's going to work.
Johnny Carson has retired, the USSR is no
more, and you don't need a 700 watt switch-
ing power supply to operate this frequency
counter. Best of all, you don't need a \A/V bus
to carry it in. The S & S Engineering frequency
counter kit is an excellent value. It's easy to
build, easy to operate, and has all kinds of
possibilities m your ham shack.
Sell your product in 73 Amateur Radio Today Call Dan Harper today! 1-800-274-7373
FREE
SAMPLE
COPY!
Aimp RADIO CLASSIFIED
Antique Radio's Largest-Cifculatfon
Monthty Magazine
Articles • Classif r&ds * Ads for Parts & Services
Also: Early TV, Ham Equip.. Books,
Telegraph. 40 's & 50 s Radios & more...
Fr0e2O^word ad escfr month. Don't miss out!
1-Year: $29.95 ($47,95 by 1st Class)
6*MoTith Trial - $1 6.95, Foreign - Write.
AM.C., P.O. Box 802-E9, Carlisle, MA 01741
^"Si Or Call: (SOB) 371-0512 0^
/4(i ^tuiuimcm^
Chassis Kits ^ Rack StieJves
Cabinet KHs Rack Equipment Catiin^ls
Assem[:>(^ Cab^iats Anienrta Grounding Kits
Slopft Box Kits Tow er Mounted Box Krts
UHF & VHF Antenna D^pole Hangers
Power Divider Kits Other enclosures
SmaJI stiests Aluminum and Brass
Charles Byers K3IWK
5120 Kanmony Grove Road, Dover, PA 17315
Phone 717-292^901
Between iPM and $:30PM EST. Cwt.
"OistribLJiorBihiip A^^jlable"
^Hhg^D"
FOR
HAMS
ONLY
RcDB KE3EE
Jcnnv K3FKI
Dave KA32NY
4309 Morthem Pike Blvd. MonroevilJe, PA 15146
{412)374-9744
FOR ORDERS ONLY CALL (800)854-081 5
Specializing in Preowned
Amateur and Shortwave Equipment
Buy • Sell * Repair • Love To Trade
We Carry All lUlajor Brands of New Equipment
We Now Custom Design & Build Computers
ForHAMsbyHAMs
All Of The Latest Hardware & Software
Cail For Details
CIRCLE 222 ON READER SERVICE CARD
CIRCLE 329 ON READER SERVICE CARD
INSURE your
Coitiputor & Rodlo Equipmont
HAMSURE coverage f of lows your
equipment wherever you take it Theft
from vehicles, earthquake, water damage
and all ottier ha2ards including surges.
Insure all your equipment and accessories
(except towers and antennas but including
rotors), media and purchased software.
Premiums start at $50. 00 per year,
HAMSURE
at
Stoesser & Vazzando Ltd.
SOO-443-6242 708 - 349*0514
Great Circle Beofings included
FIELD STRENGTH METER
Am you worried aboul
liftctfomagnetlc rgdlatfofi. TV
Eosn. distribytion to$» poor
antenna perf{)rmartc«„ or EUI/
RFI7 The DIGI-FIELD held
s1 rsT^gth meter will put you ^t ea&e •
W tr iis hvqueftcy response of DC
^^ :o 12 GHZ. il mmMf (MiecTS
' ..r iiazartjs. It !■ on excellent
tool for measuring TV coax
dl&tribuliofl loss. In addition
DIGJ-F1ELD can eaaPy find 80+11
RFt EMI Insmjmantaaon denjfil-
ng setups. SensitivMy: 0 100
MHz MwJerA" 150 nano Wafls.
ModerB' 2 nano watts.
To order cati - (800) FIELD BB (343-5356)
I^Ci. Engineering :&3ao Ventura BhMd
Surte 12S. Ef\dtro. CA 91436 PH||ia| 34$-16^ • Sl6-345^)St7 fax
CIRCLE 78 ON READER SERVICE CARD
CIRCLE 293 ON READER SERVICE CARD
MORSE CODE MUSIC!
SENSATIONAL NEW WAY TO LEARK
CODE— Do Aerobics, Sing, Jog, or Drive
while learning code! A fun & easy way to
learn or retain Morse Code skills. Now the
secret is yours with this amazing syncronized I
bfeakthroughl Great for Novice, Technician
Of the classroom. Order
"THE RHYTHM OF THE CODE"
Version 2 cassette todayl
Semi S9. 95 artiS well pay m& shppkig (o:
KAWA RECORDS
P.O. Box319-ST
L Weymouth, MA 02186
Clieck Dr iminey orckr oiify Weshiij an Offers within 5 days^
(Overseas please add $2.D0 lor ajr mal
HA r^xSents add S% sales tiK.
ClftCLE 2 ON READER SERVICE CARD
32 73 Amateur Radio Today July, 1 994
HAM
NaAional Talk Radio Show With Len Winkler, KB7LPW
America's Only
Ham Radio
ShcywOnThe
r
V
Sundays
6:00 pm EST
Weeidy CoHost, John Moore, NJTE-WeeMy DX
• i^
WHh Lee Finkel, KY7M
Tune in each week for national ham radio news, FCC news, weekly guests from
the amateur radk) cxxnmunity, ham trivia contests, prizes, listener call-in and nrxxe!
SpcHisored in part by Radio City, Inc. and 73 Amateur Radio Today.
7/3
7/1 0
7/t7
7/24
"Ham Radio & More" Upcoming Programs
Op^i Lines
IHarttey Alley NA0A, Bicycle Mobile Hams of America
Bob Heil. Heil Sound
Chris Imlay N3AKD, ARRL Attorney
Ham Radio & More is also available on Satelltte!
Spacenet 3, Transponder 9, 6.8 Auda
Rnd out what radio staAion airs "Ham Radio & More" in your local
by calling the originating station, KFNN,at6Cffi-241 -1510.
For sponsorship i nfofmatf on contact Ron Cohen at 602-241
73 Review
Number S on your Feedback card
hy Breckinridge S. Smith K4CHE
The LDG Electronics
FC-1
A small, flexible fox controller and CW I Den
LD6 Electronics
1 445 Parran Road
St Leonard MD 20685
Telephone: (410) 586-2177
Price Class: S69.95 plus S&H
If you are a serious foschunter, you have prol>
abJy tried putting together your own loxbox*
with timers, identifiers, etc. You have tried the
different circuits using timing capacitor net-
works and different chips, and you have prob-
abfy soldered in those countfess diodes in that
matrix for the IDer. Recently I tested the LDG
Electronics Microprocessor Fox Hunt Con*
troll er/CW IDer board. This small Maryland-
based company has devefoped a real gem.
Yes. the East Coast does produce some fox-
hunt goodies-
Why do you need a microprocessor con-
trollrng yoor hidden transmitter? What 1 want-
ed was a limer/lDer system thai was small,
reliable, and easy to change. I wanted to
spend more time on my own DF equipment,
helping beginners, and not spend hours build-
ing and lasting numerous timing circuits, I
wanted to be able to change the identification
and timing cycles of the hidden transmitter to
suit each individual hunt. I am not an avid
computer enlhusiasl but the LDG ad in 73
said I could program this controiler from my
PC so I gave up and ordered the board. Time
to join the microprocessor crowd*
The Board
What I got was a small assanMed 3.r by
3.6" board that was not a kit; a board with pro-
fessional printed circuit traces and a small
plug-in module for the audio, keying, and
power functions. Included in the package was
over 450 pages of documentation contained
in four separate handout/books, and a floppy
disk with numerous programming files on it*
After wading through the information ] found
the three-page fox controller sheet and the
24-page LDG manuaL
Reviewing the documentation, I realized
that what I had received in the mail was a
foxbox controller and a small singta*board
computer/processor using the 68HC11 micro-
processor. I know that there are more ad-
vanced microprocessors out there but, again.
you have to start somewhere. You can use
the system as a foxbox control!er/CW ider, or
do your own experiments with the micropro-
cessor using the 450 pages of documentation.
LDG also markets this same basic board as a
16-oulput DTMF decoder which requires dit-
34 73 i4ma^eLrrHad/o Today* July, 1994
ferent software and a different plug-in module.
Programming
The controller arrived with a test program
loaded. I recommend you test the txiard ini-
tlalfy to get familiar with the different push-but-
tons and board operations, then proceed with
your programming. You load the LDG disk
program using their disk into your computer
and then you modify the FOXMCW file to suft
your identification and timing requirements.
Their handout teJIs you which lines on the files
to modify, Using an ASCII file edit program,
you may change values on selected lines by
typing in different number values for timing,
tones* speeds, and real letters for the modu-
lated CW Identification. You then ""reassem-
ble" your changes using the assembly pro-
gram which is on the supplied disk. After you
assemble the program you can then send to
the LDG controller via RS-232 cable.
I told you I wasn't a computer person! The
loading program is written In BASIC; I spent
20 minutes trying to type in the command
"BASICA Bootload" instead of "GWBASIC,'
which is what I had installed on my computer*
I would have preferred a more detailed step-
by-step instmction sheet of the programming
2 Day
Delivery
njp to ta Ks^. ai Continental USA
-800-426-2891
Fax (612)786-6513
Call for Catalog
Ask for Ext. 22
Phone Hours
1-800-426-2891
M-F8am-8pni
Sat. 1 0 am - 5 pm
CST
Ihc.
enwood
Coupons
Extended
to 7/20/B4
S^950SDX
DD,
TS-850S/AT
^S-790A
TW\-255A
Swifl perfofmance
and surgical
precision are
second naluce to
Ihe TS-9S0SDX
Features include
diial tfequency f^
ce«ve> 1 00 memones
DSP, MOS FET linal
seciion and much
much more.
Save
•100
More
J<EW
radio wrtti lOOw
transmission capabilrttes
on all nine amareur
^nds. Ru^a;! f^iabijyiy
is matptwMk Isail^gK
elacirDnics
itic antenna tuner,
AfP system, and DOS k
line tuning.
^ ^ Save
K&nvvood^s tech- ten
nok>gy endows the --
TS-^o&AT wim MoflE
spec$ that plac^ 11 ai
the top Di amateuf radio]
equtpmenL AulomaUC
antenna tuner, 100
memones. three scan
modes. DOS, digital PU
system plus
more.
Ihe TS 790 A sets
new pertomaJTice
standards. TTie
opttonal 1200 MHz
unit, allqws tri-band
coverage Dual
band rcadDulsand
controls offer main,
sub band and even
fuli-duplojc cross-
band oporatloHj
^3849^^
M 359
TS-60S
^1 769^5
Efi|oy high pertof
mance communi-
cations plus go-
anywhere con-
v^siecics with
the iMdrkf s small-
est tOQw motsjlei HF
Irrinscetvet All mod^
and all band& complete-
this package. Limited
supplies.
Here's the h^^ln to the
TS-50. Engineered lor
90 watts onun on 6
meters. Features
include ^00 memones,
compact WG. DDS.
L.C.b. panel and
more.
1049
^1 01 9**
=1 799^
TW-742A
.tsffTJWfP*
New
VHF/
UHFtri-
bander
with
third
band qplionaJ
includes many
enhancements
such as, direct
freajency eniry.
CTCSS ancode.
DTMF remote ci>nirol
and much, much
more. Also avaOable
in a irt-band modi>l _
TM-942A
Save
•40
More
5759
I /
V Yae^u
N» Coupons
A blend of high perior-
mance foal urns bor-
row^ *fom the FT-
1000 famify are com-
billed in this affoniiable
transceiver, IF shift,
variable notch illter,
'i^arlable nojse
blanker VOX and
antenna luner arf
inc faded.
M319
FT-290RA*
Pon^lo
or mo-
bile, thi^
2 meter
aH-mode
trans-
ceiver
delivers fun and Tunc-
tion. The 2S watt linear]
amplifier dips on In
§lace ol an optional
attery case to extend
your operating horizon]
FT'790FI/1I
FT-69 an/11
$649.95
S&6I^94
569'
I « ^^Ji
This new aHl mode
mobile will provide
now fyn for 8a1eilLte.
Packet and DXjng.
Features include a
960a^t200 baud
data port. 40 watts.
DOS circuity. CTCSS
encode and much
much more.' .A.^
919
TH-78A
Compact and
confident, this
dual band HI
sets exciting
new
srandi^rtis for
portable
communica-
Irons by
combining
9implici!y of
operation wifth
a multipiiidty of
features.
TH'2BA $309.96
Save
*30
More
FT-IAB
This new HT
fxacks the
aaturas y^^
wanl in a
smalt S42e. It
features a
new alpha-
numeric
display,
super small
profile, new
square 'tf
battery
design, lit keypad, AM
air craft receive. DSQ
& CTCSS
encodie.
^295
FT-530
The rrewasl
member of
thB dual band
ramiiy. This
handheld
sports auto
fone search,
fl.2 memory
^annels^
automatic
power off.
buiit-m VOX^duahn-
band receive feature,
built-in Cftiasband
repeat fundi on and
much mcne.
449
New features
set the pace
in thts new
dual band
mobile, 8
pfograrrt
mooe memo-
hies. 72 memories,
AlP. dual in bamf
RX, CTCSS enc.,
DTSS enc A
more pfovrde a
performance
edge efihanoed
by Ihe wir^Jess
removable Ironi
panel.
SavI
More
^61 9
Kenwood's
new TH-22AT
is in a category
all its own.
This new FM
transceiver
features long
battery fife,
OTMF keypad.
user-friendly
n%enu system.
scan lunctiorfcs^ -,^^
41 memories, CTCSS
encode. OTSS. and
rnuch more
Urn Ked supply .^^ ^
Save
^20
More
248
FT-2500W
This new hand
mobile tkorrows
its ruggedness
from me FT- ]
2AG0H while
adding qreai
new feanjres
such as advance frac?
rimer, time out tuner.
A, P. O 9600 bps op-
lion, 3l meniones, the
new *omni'glow" LCD
and more! "*^ "*"
S349
Vf-BAOO
This dual band mobile
features 100
memohes. cross band
repeat, lighled
keypad, butlt-in
dupiexer and a small
footprint. Dual walch
capability juunds out
this 50/35 wall VHF;
UtHF transceiver.
Packed ready ^ ^^
599
»T>«
1 1|^ ndi bti^-l
, 1 ijT -ijjaii.r I tf4 '<|*>^* 4 fuL 4a4 n*r ttM ism. i
i^v tMim^i
vsatiof kteaadivtta Bwi
ll^rwX has^ tH*-! eosttf.
Aulhorize<t Factory Wari anty Center
We DTroT fBcxofY autharlzed wormniv scrvicii for Icom, Kenwocxl and Y^eau. We fi«rvic« ctifmaKee and models, Our customers may ssf^d any prcdud ivqutrtig Aetvi^ lo us. itnd ws
wiilt!fatidlo ii tnr Thom Tinia Is ei ono<$iop sorvlcefhi^i keepH ourciK^iomorri havinQ mors tun than h^sslo m this liobby, K yiziu noiKis custom cable for pAckaT and doo'l have lime to
maki Jt lei ye do Ll joi yoy- C.A,.P. 4 MA-HS- nwdfi are aJso awaiLabJe al fefiSiSiaiJJe ralefi, to aythurLzod, hams ynly,
2663 County Road I, Mounds View. MN 55112 Slore Hours: M-F, 10:00 am - 8:00 pm. Sat tO:00 am - 5:00 pm
Metroi {m) 78M475 • Nat1 Watts: 1«M26^2891 ' FAX (61 2) 7B6«1 3 Phone Hours: M-F, 8:00 am * 8:00 pm. Sat, T0:00 am - 5:00 pm
CIRCLE 153 ON READER SERVICE CAflD
Not Hssp/smbks For TypografMnt Ernm.
Expires
July 1994
Prices Subject To Change WrttKta Noiloe.
^ito
Courteous Service . Discount Prices . Fast Shipping
JUMBO LEDS
JUMBO SAVINGS
Liton # LTl 327C EMM
fdeal fDf €iye-C3tching indicators and displays. A recent
qjantiiy purchase of tH^se BIG. ftfnm diameter; ned drt-
fused LED& diiabies us to provi^ some very s.peciai
pricing. The fead£ on these devices have t)een trimmed
to 0 3:?5'. leaving plenty o\ room for soldering. Normal-
jy the^ parts wauM sell tor mofe than twice our pncd.
"T • "^-^^ 1 100 for $15.00
1000 for
$120,00
5for$lQQ
CATi DCfX'9200
[lOO for $180.00
9 Vdc @ 200 ma
TRANSFORMER
Three prong
grourid«d pfug
6 tool long cord
terminates
to three,
colof -coded
pigtail Seads
*^™ each
LONG LIFE
MAGNESIUM BATTERY
Rayovac «
SA-43a6'"
QuitlJor HP^^^SS^^-. ^"^^ PnC-77/
itiifitaiy K; ^^^ ^ ^i^^ PRC-2S
Ications
equipment
induding
PRC-77 and
PRC-25 radiOS-
Outpul jacks lof 14.4 volts
and 3 volts. Extremely long
shelf life, should be good for 15 yeafs storage. Meal
' jf emergency appihcatrons. S pffi output i«Kk can be
used with banana p^ygs.
9 37S^ X 3.57- X ^.or
cardboard iacketed c^se. 3 l^bs
CAT # ME-43a6
ipui- |<««W^ ^^^tl w^
4 POSITION SCREW
CLAMP TERMINAL
Four posilion, dual screw termi-
nal strip for suftace mounting.
Screw-ciamp terminals accept
up to AWG T 6 wire. 8*3* ther
mop^astic noysing. UL listed^
Terminafs and mountirkg holes
are on 0.35" centers,
4for$lQQ[i
CAT i Tm-41
00 for $20.00
ORDER TOLL FREE
1-800-826-5432
CHAl^Gi OflOSRS t& Visa, MaslC^rCafd or DiB£Dvof
I U;S^S4.00p«i(mp 4flPwiFichidi^M<.Hi PR et CAKtoila imaf |B|r M
CALL, WRItE or
FAX for a Free
6 4 Page
CATALOG
Outside 1*ie U.S. A
send $2 00 postage-
WAIL ORDERS TO'
ALL ELECTRONICS
CORPORATION
P.O. Box 567
Van Nuys,
California
91403
FAX (818) 781-2653
process, but the instnictions supplied are ad-
equate . * Jf I can do it. you can do it
During your programming you may modify
the initial delay time prior to startup, the first
and second identification messages, and the
on and off periods that wilt be repeated dur-
ing the hunt. LDG included a second identifi-
cation message feature which is unique: You
can have a push-button on your foxbox wired
to the LDG controller's "bit 1 output/' When
the first hunter finds the box, he pushes the
button and presto, the CW message changes
over to the iox found,** message, which will
now be contfnuously repeated until the con-
troller is "reset" Here in Delaware we have
had some devious hunters who have moved
the foxbox. In the case of tampering you
could even wire up a mercury "lilt" switch to
activate a tampering message to warn the
other hunters as well as the hider.
LDG mentions to "feel free to program and
reprogram" as Ihe EEPROM in the 68HC11
has a life of 10.000 cydes.*" LDG wBtms you,
and f will warn you: Be sure to make a copy
of the FOXMCWASM file before you start
changing the parameters. If you get com-
pletely out of whack you can always start
over with the original file. Since this is an
EEPROM you can remove vollage from the
unit and rt wfll Still retain the information that
you have programmed.
During your programming of the controller
you are limited to 75 characters total for the
two messages; exceeding this limit during
ioading results rn a friendly error message lat-
er One observer during a hunt stated that he
thought the plain CW messages were boring;
you can use the letters "E" "T" to produce
multiple dtts and dahs and set up a rhythm
pattern to break the monotony. Again, you
can only use 75 characters, and "spaces"
count.
Testing
One handy feature of LDG's programming
process using your PC is a test command
which allows you to test the board for your
programming changes without disconnecting
from your PC.
During my programming and testing of the
board I found an error in the published com-
putations for timing. The Fox Controller in-
structions used a value of 130 for each
minute, and my controller needed a value of
114.5 for each minute for a "tick'' value of 1 .9
per second. The values on the suppfted LDG
disk were correct except for the "tick" value
information. I talked this over with LDG and it
is my understanding that they will correct
their timing information on their handouts. For
short tsming periods this error is not critical,
but for a several-hour initial timing computa-
tion a correct value must be used.
The timing range was quoted in the in-
stnjcttons to be from 0 to approximately 7.7
hours, but my computations and actual test-
ing indicated a longer range of 9.5 hours. I
again notified LDG of this and appropriate
corrections will be made. IVs fun to hide a box
earlier in the day and have it start several
hours later on schedule while you are at the
hunt starting site. With the programmable tim-
ing you can have multiple boxes start up in
stages during the day as a complex hunt un-
folds. However, due to slight variances of the
Internal 8 MHz crystal, be prepared to have a
slight error during long timing periods, and of
course you must "arm" the controller at the
proper time by pushing the reset button. The
perfectionist can time his or her own board
for a one-hour period and come up with the
appropriate corrections.
I have abused this board. I left it laying on
my desk for a month connected to my PC
with a 9 volt battery dangfing on the power
leads. 1 abused the board further when I inter-
laced it to an old commercial 20 watt boat an-
chor. 1 hooked the board up using unshielded
wires and mounted it next to the transmitter
RF section. RF doesn't seem to affect the
processor as I positioned a quartef-wave an-
tenna with 15 watts, 3' away from the ex-
posed unit, with no problems. I then wired the
controller to the same power supply as the
commercial radio internai power supply sec-
tion, which has a receive/transmit relay on it
The inductive krck of the transmit relay didnH
bother the board. Tests conducted with the
traditional hot air blower and freeze spray
had very little effect. Overall, the board ap-
pears to be rugged and pretty bulletproof.
I thought LDG put a lot of thought into the
hardware design of their board. There are
four of those little rubber feel underneath the
board for shock mounting, and your main
hold-down bolts go through the RS-232 con-
nector so that the connector is secure when
you plug and unplug the bulky cable. The low
power CMOS circuitry can be powered by us-
ing just a 9 volt battery or any power source
up to 20 volts. During testing with the board
on the same power supply as the transmitter,
the board voltage regulator continued to func-
tion to a low voltage level of 7 volts, which is
handy if the fox battery starts to wind down
during the hunt.
The push-to-talk output of the board is an
open collector keying transistor which you
can use with a reed relay (Radio Shack 274-
232) to allow flexibility in using different ra-
dios for the bx, or if your radio allows just
grounding the push-to-talk circuit.
The 8 MHz clock crystal osctliator emits a
small signal which can be seen with a spec-
tnjm analyzer throughout the VHP range. On
my controller the signal was at 144.030,
146.030, 146.030 and could be heard about
20 to 30 feet away with a handheld. If this
bothers you, you can shreld the complete unit
in a box with feed-through capacitors. The
reason the harmonic was not on an even
MHz is a very minute error in the 8 MHz oscil-
lator.
Overall p the LDG board performs as adver-
tised, has lots of documentation, doesn't re-
quire a computer genius to program, and tol-
erates abuse. It is easy to hook up the power,
push^lo-talk, and audio outputs to your trans-
mitter. For S69.95 you can have an assem-
bled fox controlier/CW IDer to create your
own personalized system, and at the same
time experiment with a microprocessor
CIRCLE 194 ON READEf^ SERVICE CARD
36 73 Amateur Radio Today * July. 1 994
I
i
ft
I
I
%
I
J
DESIGNED FOR ONE REASON ... TO HAVE FUNi
AND BOY DOES rr DELIVER!!!
V TlM^l
*w"
ti\SO*>
%
i
rs SMAli
Moices mobiie or portable fun for more horns rtxin ever before. ^-''^^
Ffte almost any oar, even compacts. Measuring only 2.5" X 7.25"
X 9.75'', this five lb. travel companion tucks in a briefcase with X^
plenly of room b spare. ___
Recefvo' runs cirdes around rigs at twice the price. 90 dB
dynamic range, low phase noise design lets you hear the
weak ones even on crosvded bands. If s no fun if you can't
hear em!
X
^:
MADE IN
USA
' Patented "Jones* Fifter provides
variable bandwidth 9 pole ciyslal
filter ' 500 Hz to 2.5 kHz. The right
fifler for every condition of the
touch of o knob.
^SYNCHRO LOCK" software keeps
VFO virfuolly drJft free regardless of
tempenafrure variations.
Optional Noise Blonker
SSB and CW 50 Wotts Output
Adjustable To 5 Walts
Runs Off 12-14 VDC
TX '10 Amps, RX-.6Amps
Receive Offeet Tuning
Byfh-in Iambic Keyer with
Legendary QSK. Speed adjustable
on front and shown in disploy.
rssiMPii
Just sit down ond operate. AAoster every feature in minules
no modem rig is os easy k> use. Change band modules In
Q flash (o vTOfk 1 60-10 m^ers induding WARC.
les one Dom
$549 • Ircl
module of your choice
$29 * Each additionai bond module
SCOUT ACCESSORIES:
MODEl PRICE'
296 Mobile Bracket 515.00
297 Noise Blanker $19.50
937 1 1 Amp Power Supply $79,00
938 Tiny Switchmg Supply 595,00
(Only 3 lbs J)
700C Hand Mike $39.95
607 Weighted Key Poddle $39.00
291 Antenna Tuner $89.00
rsAFfORDABtE
At $549, it's half the prk^e of the closerf
compeWion.Noolherrigfxdcssomu:h
penormonce at so bw o price. Have fun
on HP wiriiout spending a brtune.
riNOTAKir
Cr/stal mixing (no synthesizer) coupJed with
meHcubus circuit design yields sparkling clean
feceive audio. And you'll rrKJPiel at the ur>
solicifed compliments on transmit audio.
CALL 1-800-833-7373
Telephone Hours:
9:00 AM - 5:30 PM Eastern
...America's Best!
nisir
TEIM-TEC
VISA, MC, DISCOVER
'Plus shipping and handling;
call toll-free Tor charges.
11B5 OiaHy Pnrlon Patfcway
Seviervdfe, TN 37a6a USA
Oflicfl: (S1S} 453-7172
Repair i>e!pi-: m^} 't2ft-oae4
Mb
Nun^bej- 9 on your Feed bach card
A Delayed Video Trigger for
Your Oscilloscope
Convert your surplus scope.
by Joseph A. Consugar KC3XM
When I began working wiih video cir-
cuits, one of the firsi things [ learned
is that you uimnot just feed a video signal In-
to aa oscilloscope and e\pect lo see any-
thing useful. The amount of time most
events ! was interested in took to occur was
so short when compared to one frame of
video, it just didn't work.
This problem can be overcome by using a
delayed video trigger This is a circuit that
will cause the oscilloscope trace !o begin a
set time after some event in the video signal.
That event is usually the vcnical sync pulse,
and many oscilloscopes include a delayed
video trigger feature. But what do you do if
you are using a surplus scope without this
capability and don^t want to buy a whole
new scope just to get this feature? You apply
a little ingenuity and build one.
The Basics of Video
To understand how the circuit T came up
with works, you shoidd have at least some
idea of the structure of a video signal. This
is by no means complete, but it should sup-
ply enough information so thai you can fol-
low the circuit description.
A video display may look continuous, but
it is actually composed of a series of still
pictures thai is going by so fast they all
blend together. Each of these pictures is
called a video frame, and each frame is
made up of two video fields thai arc labeled
the even and the odd. A new video frame is
displayed 30 times per second, so a new
video field is displayed 60 iinie\ per second.
Each ^'idco frame is made up of 525 hori-
zontal lines^ w^hich are split equally between
the video fields, Displaying 262,5 lines of
video in 1/60 of a second means each line
requires about 63.5 micros*?conds.
Out of these 262,5 lines* only 244 of them
are used to transmit video information. The
remaining lines arc used for blanking the
display during picture retrace and display
synchronization. Figure 1 shows the struc-
ture of these lines for the even field.
Picture synchronization is performed us-
ing sync pulses that are included as part of
the video signal, the main ones being the
horizontal and vertical sync pulses. Horizon-
tal sync pulses indicate the beginning of a
new line of video and vertical sync pulses
indicate the beginning of a new Held of
video. In Figure 1 , note the structure of lines
4 lo 6. These arc the lines when the vertical
sync pulse occurs. During these lines, the
sync pulses are much wider than normal,
which is the key to determining when a ver-
tical sync puise occurs.
Circuit Description
The steps necessary to produce a delayed
video trigger arc illustrated by the block dia-
/\/A,
n
»i
263
\
^ 1
1[
^
_
J LJ 1 1 Lfc
11
:
i i
3
4
i
3
■ -m-
a
*
^
Figure /. Even-fielii structwe duritig she vertical ifUenaL
nr
Horizontal
Sync
EEtTACtli?n
m
H
u
Vertical
Sync
Extraction
Divide By
Two
AdjyslabiB
Delay
Vitfeti In
H«fl:EDn1dl
Sync
VerlicBl
Sync
O^liiy
Trfggar
Delayed
Trigger
Figure 2. Deiayed-trigger block diagram ^
gram in Figure 2. A schematic of the corre-
sponding circuit is shown in Figure 3.
In order to synchronize the trigger with
the vertical sync pulse, you must first identi-
fy w hen The vertical sync pulse occurs. This
is accomplished by \J\^ U2, and their associ-
ated components.
The video siunal is taken from the source
of Q] (an MPFi02 JFET whose purpose is
to provide buffering for the video source)
and fed to the input of U 1 , an LM 1 881 video
sync separator. Tlie sync pulses arc extracted
from the video signal and appear at pin 2.
The sync pulses are routed to U2, which is
used to separate the vertical sync pulse from
the horizontal sync pulses. U2a, RL CI. and
03 form a one-shot timer that is triggered by
the ends of the sync pulses and whose nega*
tive-going output pulse is connected to the
clock input of U2b, a D type tlip-Hop. When
the signal from U 1 returns high at the end of
a sync pulse, the one -shot is triggered and its
output goes low. The amount of time spent
low is determined by the values ol Rl and
CL
The sync pulses arc also connected lo the
data input of U2b, When the output of the
otje-shot returns hiiih, the value of the svnc
signal is sampled and appears at pin 12, Nor-
mally, the sync pulse is narrow compared to
the length of the video line and the signal
from Ul is still high when the one-shot out-
put returns high. However, dur-
ing the vertical sync pulse, the
sync pulse is wide compared to
the length of the video line, so
that the next sync pulse has al-
ready begun by the end of the
one-shot pulse. Therefore, the
output of U2b is normally high,
except during the vertical sync
pulse, when it is low-. This se-
quence of events is illustrated in
Figure 4.
At this point there are two
pulses for each frame of video,
one for the even field and one for
the odd field. To cnstire a stable
oscilloscope display, the trigger
must be keyed to the same field
(i.e.. the even or the odd) each
time. This is accomplished by us-
ing the vertical sync pulses from
Video
Signal
Horizontal
Lin^O^urnber
38 73 Amateur Radio Today • July, 1994
SG-230 Smartuner
Antenna Coupler
SSB,AM,CW&DATA
ssnuiwmc*""
o»««<<f»«rasfes?i'^
5Krs
H^^M3H£
You can't buv a smarter
w
tuner than this. An automatic
antenna coupler so intelligent it
precisely tunes any length antenna
-8to80ft-intheHFbani '^
TTie Smartuner' automatically
evaluates and switches 64 input and
32 output capacitance combinations,
plus 256 inductance combinations in
a "pi'' network. The amazing result is
over a half-million different ways to
ensure a perfect match for your transceiver. And the
most intelligent feature of all is that the Smartuner
remembers the chosen frequenc>^ and tuning values,
and will automatically reselect those values -in less
than 10 ms, each time you transmit on tliat frequency
The SG-230 Smartimer; Bin^ smart.
*»*^**i''
VESS£UN'*WE
ll*f«15
SIIVL
leAQfcdQ^
voLi*fi£
_lZi
PT
an^^
PEFtf
TtSTCMJL
VOICE ooMJr*
lov
INSIDE
MICROPROCESSOR CONTROLLED • NON-VOIATILE MEMORY • WEEPROOF • BJIE. INDICATOR
10T0150 WATTS INTIT POWTR • lOmSRETl^'ING TIME • 8 to 80 ft. ANTENNA
1.8TO30MHZRINGE
fi mm %
NO COMPROMISE
COMMUNICATIONS
SGCINC. SGC BUILDING RO. BOX 3526 BELLEVUE,WA 98009 TEL. (206) 746-fi310 FAX; (206) 746-6384
* * *
CIRCLE IBS ON READER SERVICE CARD
V»d0O In
J1
Figure 3. Delayed-irigger dfvuil schematic.
U2 as the clock for a divide-by-two circuit
formed by U3a. Each vertical sync pulse
causes the ouipui of U3a tt> change stale.
The result is a square wave that goes high
once per video frame and can be used as the
trigger for the final delay circuit.
The delay circuit is composed of a one-
shot timer made up of U3b, R2, C2, and tM,
The one-shot is triggered each lime the sig-
nal from U3b goes high and Ihe pulsewidth
can be varied using R2. The end of ihe pulse
is the external trigger for the oscilloscope.
As vou look at the schematic, vou v^Wl no-
lice there are some components whose pur-
poses have not been clarified. Dl, D2, R3,
and C3 form a video clamping circuit whose
purpose is to provide DC level restoiulion
for ihe AC-coupled video signal. While not
strictly part of the delayed trigger circuit, it
is useful to keep the osciltoscope display
stable when viewing rapidly-changing video
signals.
Constritetian and Use of the Delayed
Trigger
The prottjtype for this circuit was buiit
on a Radio Shack protoboard using point*
to-point wiring. Another option would
be 10 make a PC board according to the
design in Figure 5. Or you can order one
already drilled and etched for S4.25 plus
$1.50 S & H per order from FAR Circuits,
18N640 Field Court, Dundee, IL 60118.
] recommend that you build the stages
separately and make sure each is work-
ing correctly before proceeding to the
next.
When you have completed construction,
connect a 9V battery to the power connec-
tions and a video signal lo J 1, Adjust R2 to
its minimum value and examine the delayed
trigger output at J3 with an oscilloscope.
You should see a series of very short, nega-
tive-going pulses whose ^vidih increases as
R2 is turned clockwise.
Once you have the delayed trigger work-
ing, adjust your oscilloscope to accept a pos-
itive-going external trigger. Set R2 to ap-
proximately halfway. Connect the trigger
signal at J3 to the oscilloscope *s external
trigger input and the video signal at J2 to the
vertical input. Adjust the oscilloscope time
base so that there are three or four lines of
video displayed on tlic screen. As you vary
R2, you should see different parts of the
video signal on the screen. The values given
for R2 and C2 should allow you to var)* the
dela\' from approximate K zero to about one-
and-one-half video fields.
Final Notes
When you turn on the circuit and cnnneci
a video signal, the trigger will randomly
latch onto one of the video fields. If the field
being displayed is not the one you want to
examine, move SI to its opposite position
and the opposite video field will be dis-
* • '
S • *
i • *
I *
* ;
■ •
« *
Horizontal Sync
Pulses (01, Plffil)
On«-S)tot Output
(U2a, PinS)
Vertical Sync
Pulse (U2b. P]it12}
Figure 4, Venical sync pulse extracutm process.
Parts List
R1
3.3k
R2
1 meg potentiometer, lir^ar taper
R3
Ik
CI
0.0047 |jF
C2
0.033 |jF
C3
0,1 mF
D1.D2,D3,D4
1 N91 4 silicon dtode
Q1
MPF102JFET
U1
LM1381 video sync separator
U2.U3
4013 D type tip-f op
J1.J2J3
RCA phono jack
SI
SPOT swjicn
Note: Resistors are all 5% 1/4 watt. Capacitors
are all poiyesti
?f type.
40 73 Amateur Radio Today • July, 1 994
XKC3XM
IN
h
01
^ L
1 1 »
leacr; >
mm
'L
^-
JLj
x
''T'
s
" L
w
^
y2
o
AV
9VDC
S1
Mm
.31
UG
^
played. There is no
way to determine
which field will be
displayed when
you turn the circuit
on, but vou can al-
wavs get to the one
you want.
For those people
who are familiar
with the LM18S1,
yoy may wonder
why T didn't lake
advaniagc of some
of its other features
(e,g„ the even/odd
field indicator). It
has been my expe-
rience that in order
to fully utilise
these features, the
video signal being
examined should
conrorm closely to
the video standard.
Unfortuna tel y,
some video sources
(c.g«, VCRs and
camcorders} take liberties with that standard. The circuit as presented was designed so that,
with hope* it would work with as many of these near misses as possible. If you work pri-
marily with standard video, I encourage you to take advantage of the additional features of
the LMi881 and share the results with the rest of us*
VSDEO
TRGER
I
tt2
TF!1G
OUT
B2
qiDfiA?x«i
J
Figure 5. PC hoard iayauf and parLs placement.
ARfSOO
5QQKHZ TO 1300
MHZ, WITH BFO
AR1500 A 1000
C/icinnef Scanner with
SOOKHz to 1300 MHz
coveragCi & no cycouts.
10 search. 10 scan banks
lockout on search &
seafch&storc. VFO tuning
with AM/FM/ WFM modes.
With Nl-Cad batteries, Chgr,
VHF Ant., and long wire
antenna, case & belt dtp. Limited time offer,
not valid with any other spedab. Only 5.95
shipping & handling anywhere in the 48
states. Call toll free and order this new unit!
«
COMMUNICATIONS
Call
1 -800-445-77 17
Sell your product in 73 Amateur Radio Today
Call Dan Harper today, . , 1-800-274-7373
6975 HiUsdale Q, Indianapdis tN 46250
317-842^7115 Fax 1^800448-1084
Ct^CUE t64 ON READER SERVICE CAflD
W9GR DSP II
What is DSP? DSP ailows the
"cons iTuct ion" of various filters of
great complexity by using computer
code. This allows us to have easy
access to a variety of litters, each
perfectly optimised for whatever
iTtode we am operating. The DSP II
has been designed io operate in 10
dfffe refit modes Four filters are opHmized for redticing interlerertce to SSS phone signals
ffom CW, iieterodynes and random noise interference. Four more fillers operate as
"brick-watr CW bandpass filters. The remaining two filters are designed for reliable
recovery ot RTTY and HF packet radio information signals. A single front panel switcfi
selects any ot these filters. Easy hookup to rigs speaker jack.
• The W9GPt DSP n is me most popular D&F on the market —
Thon^nds in use wofkiwidaf
WSOR DSP Filter .$299.95 12V DC Power Supply ,, ..„$11,95
HaniBase 1994
Nmr data! New Program!
Great Circle Beam Heading
Ham Base 3.06 is packed with all of the naw f«a1ur«s
you h3v« be&n asking tor:
* Browse by Name.
• Browse by Callslgn.
• Browse exported Files. Throw away yaur
' Export data in all the popular database formats, rnagnifyteig gi«»ft».
Address iabels: Fixed format: Delimited ^ commaSt
tabs, com ma -quotes: calls^gn only.
- Generate maUing lat>els from Callstgn Lists.
* Color menus and popup Help screens^
• ExfTort lists by State, County, and Zip Coda.
«$plft databases to multiple hard drives and floppy dlska.
* Same Low Price, HamBase 1 994 is OfUy $49.95.
AvaMabiB m 3 1/2' or 5 tM' IBM PC fonnat (Speoty)
SDP^GOO
Make and receive phone calls from your mobile rig or handie-talkfe with
your own personal autopatch. Connection is easy ^ just hook-up to the
mike arxl speaker jacks on your base station rig ar>d plug into the phone
linef Complete control is assured through touch -tone access OOdes that
you set and change at wiil. Long distance toll access is controlled by
speciai cooe thai you set. preventing fraudtiient usage. All programmable
codes and set-ups are stored in special non-voiatiie memory immune to
power faiiures. Repeater owners ijse the SDP-600 as well for reiiable and
solid repeater autopatches. Power required Is 12 volts DC at 100 MA.
Experience the freedom of owning your own autopatch, on you own
frequency, to use when
ar>d as you wish. The
SOP-eoo is made in the
USA and cames a one
year warranty.
SDP-600 Personal
Autopatch, fully wired
...$249.d5
J-Com Transceiver Control Computer Interface
The j"Com Transceiver Control Computer Interface Is functionally Identicat to the
Kenwood iF-23?Ci loom CT-17, Yaesu F]F-232C, Ten-Tec 305 and Heath
computer interfacas. It will work with all radios and rig control software which use
tttese Interfaces,
« No external power supply is
necessary. The ]*Com TC interfaces
require very little power for operation.
This power is obtained directly from
the computer COMM port.
• All electronics are enclosed in the
shielded DB^25 connector hood,
RFI susceptibility and radiation is reduced, S54-95
• Fully assembled and tested,
• Fully Hardware and Software Compatlbfe, Works wfth aff rig contrcined software —
Free shareware disk included I
ar-i->it-i«^+i--eqv-i4>i^«»
SDPA 12 voff power
suppty ur^it.,„$11.95
i-COM • 793 CAMMING PKWY • VICTOR, NY 14564
ORDERS CALL 1-800-446-2295 ORDERS ONLY
TECH/OHDER/tNFO i71fi)924-45S0 FAX {716)924-4S55
TERMSi Siatt^rKtion guarAnie«d. Ejcsmiiw fof 10 dtys ^ ty<A plnSRf ntum m ongmul torm
fur mlumf Add Mas iot 4hipping handJrng arn3 mtuTatrc* Fof tofeign ordc^rs ^cJd 20*- tOf
9^urfac« mail COO (U.S on^yji add $5 Da Orders under S20 ackt S3 DO HV rvitd«fit» MkJ T%
sit\e» lax. 9a-diiy parts HvurTAnry on fcit pans l-y*ar parts A la*»f «fstrarty on wn«i utiii*.
RAMSEY ELECTRONICS, INC 793CAWNING PARKWAV VICTOR NY 14584
CrRCLE 5S ON READEfl SERVICE CARD
73 Amateur Radio Today • Jufy, 1 994 41
Ntimlier 1 0 on your Fsedback card
M ultiband Half- Wave
Delta Loop (MHDL)
A simple 20- 1 0 meter antenna with an 80-30 meter bonus
by James W. McLelland WA6QBU
While looking through my books for
some kind of smull antenna thai would
fit in the attic, I happened upon a short de-
scription of half-wave loops. Tve always
preferred full-wave loops, but a 20 meter one
woijldn*t fit in my 17 \ 25" attic given the
fact tltai 1 needed to stay away from oulside
rain gutters. Hushing, downspouts, vents and
a chimney. As luck would have it, however. I
discovered thai a half- wave loop fus, with
room to spare (Fve hung it on my classroom
wall as well). While half- and full-wave
characieriHtics are quite difterent from each
other, with the details worked out, the
MHDL has proven itself to be an effective
indoor reference antenna for the upper {20-
10 meter) HF bands. (By ihe way, there's a
slick trick you can use to make it work on
SO' 30 meters as well.) It's easy to build, re-
quires no alignment and the XYL can*l see
iL Try it, This'll be the easiest antenna
you've ever built.
Description
The loop is cut for a half wave on 20 me-
ters. Half-wave loops have a very high
impedance, in the order of 2,f)0D ohms, so I
needed to bring the impedance down to a
more workable value. Using a quarter-wave
(including a velocity factor of 0.80) trans-
mission line transformer will drop the
impedance to ahout 50 ohms- 1 used 300
ohm twin lead (Radio Shack 15-1153) be-
cause it works well into a tuner, is inexpen-
sive and has low loss. On 10 meters, the 20
meter half wave becomes a full wave and the
impedance drops to about 100 ohms, the
fecdline is now half-wave and acts as a Irl
transformer, which your tuner will have no
trouble matching. I also found that my tuner
could easily resonate and match the MHDL
on 17, 15, and 12 meters. If you use a 3/4-
wavelcnglh fecdline, you can also get an SO-
SO meter bonus bv shortins the two feedlinc
wires together and tuning it as a top-loaded
vertical. This gives you a vertical 3/4 wave
on 30 meters, a half wave on 40 meters and a
quarter wave on 80 meters. However, you
must use a ground to make this mode effec-
tive. By the way. it's about 1/8 wave on 160
meters and vour tuner niisht be able to add
42 73 Amateur Radio Today - July. 1 994
enough inductanee to make it resonate. Any-
way, it's worth a try.
Construction
Using insulated #16 or #18 gauge strmded
wire, cut the loop to 35' 4" (see Figure 1).
Now cut the 300 ohm feedline to odd mulli-
pies of 13' S" (exactly 4 r for the 80-30 meter
bonus). Solder the feedline to the loop ends
and insulate with shrink tubing. Then, to
connect it to the balun on my tuner, I in-
stalled two banana plugs (the kind that plug
into each other) on the end of 6" pigtails^ sol-
dered them to the twin lead, and then insulat-
ed them with shrink tubing. You'll be done
with the construction phase in less than an
hour
Installation
This ts the part where you can really get
creative. You might even hide ihe feedline
and convince the XYL thai your MHDL is a
IT
rosebush trellis, bui then you'H have lo plant
and take care of the roses. I opted to bang
mine horiitonially from the rafters. There is
no exact shape requirement except to have as
much area as possible. I like equilateral trian-
gles, but squares, diamonds, circles and rect-
angles work just fine. Changing the shape
varies the frequency somew^hat (plus or mi-
nus 1/2 MHz or so) but I just let my tuner fix
it. More importam is that the loop fits the
space you've got no matter what it looks like
and what anele it*s mounted at — vertical,
horizontal, or somewhere in between. One
warning: Slay away from metal objects with
the MHDL and feedline. and mount it with
some kind of insulating material. If you have
extra room, try a venical and a horizontal
model, at least for 20-10 meters. Being able
to switch back and forth can really be dra-
matic because the angle of radiation as well
as the polarity will be different. Lastly, if you
go for the 80-30 bonus, the feedline should
be somewhat vertical and stretched oui, bui
the higher part could be horizontal and work
OK in anv case, it's a lot better than nothing
and it^s all hidden indoors.
41'
300 Ohm Twin Lead
To Balun
And Tuner
Figure 1 . The MHitilxim! Half -Wave Delta Loop.
Parts List
Quietffex #14 antenna wire
KHowan 300 ohm twin lead
Stirtrvk tubing, 2/8'
Stifinik !ubing. ^'16"
Banana plugs
Dacron line
Egg insulators
36'
4V
r
r
2
50"
4
Note: Alt parts needed to build this antenna can be obtained by ordering the Mufliband Hall -Wave DeHa
Loop Expenmantef's Kfl from Antennas West, 1500 N 150 W. Provo UT 84604: TeL (801) 373-8425- \n\w
dudory price w/shipping (40% discount tor 73 readers): $24.
There really isn*t an}thing thai you need
to tweak oil the MHDL, Siirc, you could use
a lancy antenna bridge to irim it for 20 and
10 meters once it*s installed* but you*ve got
to use a tuner for ihe other bands an% wav. so
why bother? For 20-10 meters, ju.st connect
it to the balun tcmiinaJs and tune for mini-
mum SWR with the lowest power you can
(check for a cbar frequency first), then look
for a QSO. On 80 and 40 nteiers, plug both
banana plugs together into the single -ended
"wire" tenninal on the timer and connect it lo
the best ground you can gel. For easy band
changes, I keep my setting wrinen on a card
next to the tuner. It tunes quite broadly su
me setting for each band gets me close
enough to gel started, and then touching it up
is very^ easy.
Testing
Does it work? You bet it does! Tve
worked as far west as central Russia and as
far east as Czechoslovakia, or is it the other
way around? North to Alaska, and south to
Argentina. New Zealand and Australia were
also no problem, OK, OK! I know. The
bands aren't as good as they used to be, but it
still is a pretty good antenna for being in my
anic and if you don't like it maybe the XYL
can hang cioihes on it — hey, wail a minute! 1
think Fve got an idea.
Why buy a TNG?
PCHFFAX+PCSWLOT.00
SPECIAL COMBINATION OFFER
For ^ limiied time. i\ you order PC HF FAX $99 {see our
oihef ad m thfs ts&ue). you can add Oi4f n-ew ara improved
PC SWL 3 0 for SfiO 00 t^Sead o< cur regtiar low price d
S99 00
PC SWL «Bn*»ns the narc^imare. software rtstmaoos
*Td troquency -'St^ neeced lo aiksw you to ^ece-^fe a vas:
varr-ety of digital bfoadcasts iransmi'tted over shortwave
radro. AJli yoy need is any IBM PC cjt coiTipadible computer
arid an S$B shortw'ave receiver. The product consists ot:
Defnoduiaior
D^gtiai Signal Processing Software
200 P99e Tutorial Retef€noe ManuaJ
Worldwide UtiTity Frequency lisi
Tutorial A^dio Cassette wrth s^mpjies
PC SWL. a-toiTiat»ca y cecc^t'S Mcf&e code RTTV.
AMiTOR SI TOR MVTEX sr»0 ASCII
PC SWL leis fOu h*ne \^ o^' wodd press se-vices
meteor otogcai broadcasts, ham radio operators, coastal
shore stations, avialion tetex and much more digiial action
on the shof^twave Dands Why pay for another exoensive
bcjt wher & s!^:^!^ ■"'*ei'ace a-nd your PC can do tirwi pcP
ADVANCE 0 FEATURES:
Tuning OscPCSCOpe
Oigitai Waw«iotf^ Preseriraiicns
Auto CasieraBlton arid Code Recogrwtian
Cont^n^iOu^v TunaDie Finer Froquericiee
Variable Si^ifl
Adjustab-e CW Filter Sensitivity
Unattended Capiure ancf Pnnting
Integrated Text Edfior
Integrated^ Log and Database
Shel to DOS appicaffton^
Seamless tmegr^rinn witr PC HF Facs^nle
C^\ or wrf!e for our cornpiete catalog ot pro^lucts
Vt£a & MasterCaJ-d welcome
Software Systems Consulting
61 5 S. E( Camino Real, San Clemenle. CA 92672
Tel: (7 14)498-5784 Fax:(714)498-0568
CIPK:LE 244 QH ttEADEft S£I)V1C£ CARD
HF tnobileer's "dream" antenna!
The #f/ffitf iS/ERIM an ten n a :
Operatieaiiyv\1icrefiijni3.5IVIH^
to30MI l2>W///f>/#/ leaving your
car, "MonobaiTd**perfi3rnnaiice!
'
$289 plvLs S&H VISA/MC
(mounts and whips sold separateKO
Box 2389
Nevada CHy^CA
95959 USA
Tel: 916^273^3415
Fax: 916-273-7561
Broch lire Available
CmCLE 87 ON READER SEHVJCE CARD
THE MAGIC BAND - SIX METERS. The
great DX during band openings and full
BUILTTOMIL-STD-810 2
SPECIFICATIONS
Frequencies: flX
IX
best of both HF and VHF. Enjoy
repeater operation at other times.
YEAR WARRANTY
TO PLACE ORDERS
CALL 1 •800-643-7655
Sensitivity:
Memprles:
Tones:
Keypad:
DC Poyrtn
PCS-7500H
Az-ei
46-54 MHi
46-54 MHz
5(hS4MHz
a)'54 MHz f
S(V5Vteas
SUSJfete ^
<ai9iAr
<016|^
forl^dBSNAD
{or 12 dB SINAD
2G
40
38
38
BacKlit DTMF
Prog aid DTMF
#13.8 ^C#
+12vOCi
9»pS(W
nwmm)
OpnilBSQVCf
46t0 4l§VDC
TM.^^^IW^
6.85'Hi^2.fi'*Wxl.3^D
PCS-75Q0H MOBILE
AZ-61 HANDHELO
^AZDEN
j,^ 1/ \^_L^i_| M H7NewHy(tePSi1(Ri*.,RanfctinSq.liYT1010
^^mff,ul^J!7Zn^ytii,i^n (516)328-7501 FAX (516) 328-7506
73 Amateur Radio Today •July, 1994 43
Nuinbef t1 on your Feedback card
The Improved Resonant
Feedline Dipole
A compact, low impedance, end-fed HF antenna that needs no tuner!
by James E. Taylor W20ZH
The end-fed RASER antenna described in
73 Amaieur Radio (September 1992, pp*
8-14) utUtzed the RFD (Re&onani Feedline
Dipole) approach. TTiis concept has drawn
an cnthusiaslic lesptmse from hams through-
oui the cooniry. li achieves an end-fed
dipole, or a RASER, for any band desired
asin^i^ a coaxkil feedline and wiihoui a mnen
It has been praised by many who have site
rchLnciions which prec[iide the use of the
custonnary dangling center feedline, A
unique feature of ihL'se antennas is the use of
the T-chokc — eg.: a 13'lum coi! of coax
which is .suspended at ihe input end of the
radiator If, however, you find such a coil
cumbersome the present article offers help!
The RFD Concept
As mentioned in the previous articles, an
obvious approach to the electrical isolation
of the input end of the dipole might involve
the use of a current balun. However, calcula-
tion showed that this direct approach would
not provide sufficient impedance. At that
time 1 chose to use the somewhat more
bulky T-choke method of isolation. Never-
theless, the idea of making a more compact
choke was rekindled when I found an article
in my files by Joe Reisert WIJR (Ham Ra-
dio. September 1978, pp. 12-15). Thai arti-
cle described **a new type of balun" which
featured a high permeability toroidal core
wound with coaxial cable using opposed
windings for reduction of external field, as
showTi in Figure L Based upon that idea, T
made a few comparative impedance calcula-
tions, which were encouraging. Experiments
then led to a simple practical design in
w hich the T-choke is replaced by a compact
box,
I will describe the final design of the RFD
antenna for the 80 meter band in some de-
tail, and tabulate the results of the calcula-
tions in the "Calculations" sidebar. Also in-
cluded is a tabulation of the calculated num-
t>cr of turns and lengths of the dipole halves
for ihe other popular HF amaieur bands.
The Design
In the previous design of the RFD the
self- resonant T-choke served two related
functions: It gave the high impedance re-
quired to isolate the end of the dipole, and it
provided the reactance which tuned the sys-
tem to resonance, thereby enabling an excel-
lent impedance match to the feedline. In the
improved RFD design these functions are
achieved by adding a fixed resonating ca-
pacitor in parallel with a winding of coax on
a toroidal core, as in Figure I, First, calcula-
tion shows that if we use the Type T-200-2
powdered iron core commonly used for
baluns in this frequency range the induc-
tance would be an order of magnitude lower
than that for the T-choke. Even two such
coils in series, tuned to resonance using a
264 pF capacitance, is low^er by a factor of
five. In spite of this I temporarily wound
two 13- 1/2- turn coils on these cores for pre-
liminar)' experiments. The resuhs confirmed
the feasibility of the approach but tlie mea-
sured common mode current on the feedline
was too high- (The MFJ H-field Antenna
Probe is convenient for comparing these cur-
rents). However, during this test an impor-
tant fact was determined^^/j order to get the
desired 1:1 SWR it was necessary w place a
current bahm in the line ahead of the tuned
coils. For this I used a 2C)-tum bifilar coil on
a T-200-2 core. This cuiteni balun provides
impedance balance relative to RF ground.
Further review of the Amidon data sheets
indicated that we must consider ferrite mate-
rial, which provides higher penneability, in
order to get the higher inductance desired.
However this comes at the expense of some
reduction in lemperature stabiliiy. The FT-
240^ 1 core w as chosen for our desired pow-
er levels and frequency range. This core has
an initial pcmieability of 125, and with a
core o,d. of 2.4 inches it should handle a
kilowatt of povvcr without excessive heating.
The calculation of inductance of a 12-tum
coil on such a core gave a value of 25 micro-
henries— much greater than that of the pow-
dered iron cores and even greater than that of
the RFD T'Chokc. Since the loss resistance is
roughly a factor of five less than that for the
original RFD, the calculated prognosis for
the Improved RFD is very promising! (See
the Coil Tester comments at the end of this
article.)
Const ruction and .\djustmcnt
For the fmal coil I w^ound 6 -f 6 turns of
RG-8(M), field-opposed, on an Amidon
Type FT'240-61 toroidal core (see Figure 1).
This coil was mounted in a 6" x 3-3/16" x
1-7/8" plastic box along with the current
balun referred to above and the tw^o coax
sockets, as indicated in Figure 2. For the
PhoioA. An early version of ihe "box.
44 73 Amateur Radio Today * July, 1 994
ff
Photo B. A plastic pi I! InHtle does the trick.
■KM «»«»•■■"
-■M/tt
I 11
■ 1 «
I T^ -I-— M] ^lifLSn
.yirlliililA^
'Fniiimr
4 W 5 8 1 s e
iifiiiiimii
gipTA MfTO Um^F* OH.
WWW
I'.l.
ii
llMIIIIIUIIIi
OPtOaKTRONICS
MODEL WHO UhlfflklnAJH CHHriiMlniffr
4hO^¥3
UlS^.ili
miiiiiiiiiiii
«ri fitpi tmt™ *ttitr:ii
P^Mt^l^UU
» ^-..iirn
**
Lrvi
■^
i
SENSITIVITY • SPEED • DISTANCE • POWER
Model 3300 n29.
IMHz-2.BGHz MiniCounto-
* True pocket size
best curtdooR \Tsimlity and
longcT l^ittcn' life
* Sekasag;ate dines
* Diiea&pre-soMnn^
Model Ml m%
10Hz-2,3Cl h HandiCounBo*
•High^OElO
• Digital Filter grcaly induces
[aEvifHn noce & osdJUcioa
• Digiial Amo Gipturc lode
oHjit^T displn' on fiat
tt^^g to psss dm
•SHoutNICkI
MODig^BaddkLCDdispl^
* 16iqpnentRFbar^apii
* Aim/SiJOfr bunon savres &:
reoISs ftequendcs
• 25OMH1 dirrct owrt
* D^inl &>tnimiiikarions Port
pennies data log^ng with
optiond o^mtitcr St M>few3i?
Order Toll Free
1-800-327-5912
In FL 305471-2050 FAX: 305-771-2052
582 1 NE 14th Ave, Ft. Lauderdale, FL 33334
Model 3000A ^32?.
10Hz-3GHiHandiCouniei*
•High speed OEIO
• Didd Filter msiv reduoes
• D^g^ AuBD Captuir bcb
cminicr dispby on &s[ ftading
ID pass Stier
•6HourXiCad
<10I%rBdditLCDdts|^
• 16 s^pKni RF hai^raph
• Ami/Stotc butiofi stons &
lualls&cqiienaes
• 250MHz dirca couni
• Digital Communiarions Poa
permits 62.11 lo^ng with
optional convener & sokwaie
• Muln-fiinction; Fi^ticiKy,
Period, Ratio & Time
Interval Measurement
• Dual High Inipdancc Inputs
^ AnipliHerii
• Built In High l''ass Filter
Model 8040 '679.
Bench Portahle &>utitef
With aS thefcamm if die
• Dual SOOhm and 1 Kte Ohm
input ampli&Ti wah AC/DC
IfvdadftM^ lim' Pas& Fiker &
AtmmtitDr
• Iiufitt^ dock output/
Boonai dock input
• RS-232Said oompuDcr
intEfbcE
• Opcwnal ± 0. 1 ppm TCXO or
± Q.OSppm K\^G o^tnizcd
Whenwu order mk a/mtt omjidl
Ime ofAjitmriits timl Hlftfn to gitfe
you vuiximtmi pick-up f/ktanO! &
mir I^ohes mta Product Aaasorks.
I ■%
im
▲
k
5%
mdlmg (Mai S 10) US, Canada ' 15% outside ajnriacntal US. * Vta, Miffcr Card. CO.D., Cash or Moikt Order onfjr.
simple bifilar currenl balun [ wound 20 turns
of sheathed bell wire on the T-200-2 core,
shown schematically in Figure 3. The gener-
al packaging is shown in Photo A, which Is
of an early model. Figure 4 show si the
schematic diagram of the circuit. The sim-
plicity of the circuit is apparent — other than
wire and coaxial cable fittings, there are on-
ly five parts!
I have found that a plastic pill bottle (the
popular amber-colored cylindrical one with
the locking cap) makes a very useful center
insulator for this type of dipole. 1 mounted
SO-239 sockets on the bottom and the top of
the box. Connections are as indicated in Fig-
ure 5. Photo B shows this compact, rugged
assembly. The unit can withstand a surpris-
ing amount of tension and the parts are con-
veniently disconnected, when desired. Fig-
ure 6 shows the complete antenna.
The only adjustment required was the
choice of the tuning capacitance connected
across the coil of coax on the ferrite core. I
made a preliminary adjustment by using an
air variable across the coil on the bench, and
Photo C. The radiator, suspended hy two 40-foot'high masts. The box is at the lefthand mast
and the center insulator is near the righthand mast.
RG-a (Minifoam)
6 + 6 Turns Opposed
Ferrlta Core
FT-240-61
Figure L The Improved RFD Antenna's coil.
using the coil tester described at the
end of this article. I then made the
final adjustment with the antenna
in pUce and with the plastic box
lowered to stepladder height, using
an SWR bridge to indicate 1:1
SWR, These adjustments agreed to
within about 10%. The air variable
was then replaced with fixed silver
micas and the box was raised to
normal height. (Since the voltage
across this capacitor is high I
SO-239
Tuning Capacitors
Selected For
Frequency
Enclosure: RS-270-223
Tuned Coif
6 + 6 Turns
RG-8 (M)
Current Balun
20 Turns
Bifilar
J
SO-239
placed two equal capacitors in series-) For
my installation 50 picofarads (2 x KM) pF in
series) brought the resonance within 1 5 kllz
of the desired frequency of 3,953 kHz.
Results
The adjustment and operation of the Im-
proved RFD Antenna on 80 meters was
straightforward and satisfactory in all re-
spects. The radiator was suspended between
the two 40-fooi-high masts which support
the two RASER gain dipoles at W20ZH,
This can be seen in Photo C, where the box
is at the lefthand mast and the center insula-
tor is near the righthand mast. The '^termina-
tor" half of the dipole slopes downward off
of the photo to the right. (The segmented
sections sloping out of the photo from the
righthand mast arc not part of this antenna
system.)
It was interesting to observe the action of
the tuning capacitor in limiting the shield ra-
diation and matching the radiator to the
feed line. The shield current was indicated by
the MFJ H-field probe and the match was
measured by an SWR bridge while turning
die air variable capacitor. At resonance the
shield current showed a sharp null Also, the
SWR was a flat 1:1 at a point slightly off
To Tuned
Coax Coil
20 Turns Bifilar
(40 Turns Total)
T = 20 Turns Bifilar
On Am id on T-200-2
Powdered Iron Core
From Transceiver
Figure 2. Connect the transceiver to the bottom of the box.
Figures. Schematic for the current balun.
46 73 Amateur Radio Today • July, 1 994
KEYNOTE SPEAKER
Why pay over $400 ft
separate accessories:
Speaker
Adjustable Fitter
Recorder Activator
Audio Antpiifier
Audio Activated Squeich
Noise Limiter
from Grove!
When you can have it all in the
new Grove
The Grove engineering team has aeateti the most revolutionary audio
accessoty cin the commuiYication market: the SPZOO Soand Enhancer.
Housed in d stylish, soEld oak cabinet hand crafted in the mountains of North
Caroliixa, the SP2Q0 is sure to enhance any room and radio receiver. Ttie
control panel, constructed of sturdy, btack aJumfnum, has been designed for
optimum ease and convenience when tuning and refining signals.
The SP20D combines a powerful audio amplifier, top^f*the-line speaker, and
an adjustable filter system in one to aeate the most vei^atile and precise
listening environment ever ava liable to radio enthusiasts. The keen peak/notch
filter system and advanced noise limiter allow the listener to pull clear and
distinct signals out of tlie haze of interference and background noise, while the
adjustable bass and treble provide the flexibility to create just the sound you
want F5K, RTTY, packet, FAX, CW and all other data systems are enhanced
while Interference and electrical noise are reduced or even eliminated by the
analog audio processor.
The SP2(MI also comes equipped with a stereo/mono headphone Jack, for
prh^ate listening, and an automatic tape activator so that you never have to
mi^ anything.
Try the new Grove 5P200 Sound Enhincer with your recerver, scanner, or
transceiver and enjoy the latest in speaker sophistication; you'll agree this is
truly a keynote speaker!
SPECIFICATIONS:
Power Required: 12 to 14 VDC @500 mA; 120 VAC adaptor ind.
Audio Power Output: 2.S W @ 10% THD (S ohms)
Audio Sel«ctlv[1y: Peak/notch 30 dB or greater, 0.3-6 kHz
Squeich Hold: 0-10 seconds
Moise Limiter Adjustable-threshold pufse noise clamp
Tape Activator; Audio activated (VOX), 3 second hold
Tape Output 500 mV P-P @ 600 ohms (nom.)
Headphone Jack: Universal mono-wired stereo jack
Dimensions: 10-7/8"W x 6-7/8"H x 7.1/4"D
CALL NOW! (800)438-8155
(704) 837-9200
$
Order SPK13
* Plus *7" UPS Ground Shipping
GROVE
ENTERPRISES
Changing the way you to
hear the world
CIRCLE SeO ON READER S&tVlCE CARD
To Oipole
F«edline
6+6 Turns
RG-G(M) On
FT-2^0-61
Toroidal Cora
50-239
50 pF
(Selected For
Desired Fle^onance)
Currenf Bslun
(Rguro 3^
30*239
From Transceiver
Figure 4. Schematic for the Improved RfDs
box.
Specifications for Other Bands
Band
Freq. Turns
DIpole Half Length
160m
1.9 17
123'2''
80m
3.954 12
59"2"
40m
7.263 d
32'3"
2Qm
14.29 7
16'5"
17in
18.14 6
12'ir
15m
21 .38 5
10'ir
10m
28.05 4
8'2"
resonance, as expected. Noise bridge mea-
surements confirmed this resonunt frequen-
cy and indicated an input of 52 ohms. The
measured bandwidth of the sysLem was 170
kHz between ihe "SWR = 1,2" points, which
is very accepiablc. The common mode
shield current was appreciably less than
for a standard well-balanced center-fed
dipole. Stations worked reported no differ*
ence in signal strengtlis between these dipole
antennas^
Conclusion
The Improved RFD Antenna is an end-fed
dipole using coaxial cable without a tuner. It
achieves the same advantages as the original
RFD system, while replacing the T-choke
coil with a compact t>ox. It also provides a
more convenient method of adjustment to
resonance.
I wish to acknowledge the patience of the
number of hams who gave signal strength
comparisons which confirmed the viability
of the design.
Coil Tester
Michael Covington {73 Magazine. Sept,
1990, pp. 48*51) described a simple coil
tester which gives a direct measurement of
the resonant frequency of a parallel -tuned
Lock-Top Pill Bottle
2-1 /2"L X 1-1 /4« OD
SO-239
To "Injector"
50^239
To 'Terminator
.fi
Figure 5. Center insulator assembly.
1
RG-8(M)
5§' 2^1 4"
Antenna Wire
59" 2-1/4"
^ 1
n
^^
-^ M-359
^^^^ 1
\j
\
f
Support
^ Box
(Figure 2)
Center Insulator
(See Figure 5)
Insulator
Support
Feedllne
Figure 6. Improved RFD Antenna {for J.95S5 MHz}.
Parts List
De&crlptlon
Part Number
Optional Supplier
1 ferrite com
FT 240-61
AmidOn Assoctales
1 powdered iron co^
T-2CK>2
Aiiiick>n Associates
1 enclosure box
270-223
Radio Shack
1 piastre pill box
1*1M'^0.d,. 2-1/2" H
Any pharmacy
Silver mica caps
Assorted (ioo/$5)
Fertiks, 5400 Ella St., Phi a. 19120
Antenna wrfe
#14 Stranded
Radio Shack
4 coax sockets
SO-239
Radio Shack
5 coax plugs
K-259
Radio Shack
5 coax reducers
UG-176
Radio Shac*^
1 right angle conn*
M-359
Radio Shacl<
Coaxia cabe
RG-8 {MnifoamJ
Radio Shack
Twin bell wire
(Sheathed)
Any home supplier
Calculations
Kern
Equption
Value
13 Tum TChoke:
L=aXn=XJ =
20|jH
^i (OLD^ -
25X10^1l1 fOLO)
2x 13.5 Turn T200-2:
L = 1Q"^X|Sf^XALX2 =
4.3 pH 1
(i.e. IRFDIJ
^T (RFD1> " '-'^ ^ ^1 -
2.4 X 10 m, {IHFD1)
6+6TumFR-240-61:
L ■ 10"* X N^ X Al =
25|jH
{I.e. IRFD2)
^(IRFD2> = UC X R^ =
64 X IOVr, (»f,to2>
Z Comparison:
2tfF|FDij/2j^pjpQ2) =
0.2S
^t(iRFDa) '^i(RFDl) -
12.5
coil. This tester, together with my Alfa digi-
tal muliimeter (which measures frequency
up to 20 MHz) gave a direct preliminary
measuremem of this antenna's tuned-coil
frequency.
Core Kit
Tlic two toroidal cores for the Improved
RFD are available as a kit from Amidon at
a reduced price of S12 by referring to this
article.
48 73 Amateur Radio Today July, 1994
l?T7y LOOP
Number t2 on yow Ffeedback card
Marpf. Leavey, M.D., WA3AJR
€ Jenny Lane
BaiUmoreMD 21208
Over the past few nrionths. we have
looked at a few shareware pfograms
tor FHTY. This month, let^s take a look
at a commercial package— a package
thai offers quite a bang for the buck.
The program is BMK-MULTY, a PC
program for running RTTY with an ordi-
nary "dumb" terminal unrt and an IBM-
compatible computer. Developed by
G4BMK, who has been wriling RTTY
SOftweie for nnany years, this progmin
takes advarrtage at the processing
power In the persortal compuler lo inte-
grale the functions of a terminal node
controller into the software.
With this setup^ some of the prob-
lems associated with the hardware of a
TNC. such as extra RF noise, is ellmi-
nated. This presumes, of course^ that
your computer is adequately shiekJKJ.
Since the computer itseif is the TNG.
communicatifkg with the demodulator is
Integral lo the system, eHminaling con-
cerns over intemat baud rate, data bit5»
and the fika
Lets take a fook at this package
and see just what it can do. First off, as
noted, it will run on just about any PC-
compatible, from the oldest 8088 run-
ning at 4.77 MHz to the latest superhot
screamer Some highly intense modes,
sucti as PacTOR and SSTV, however,
may not run well on a sk^w machine.
While not rated to run under Windows,
some users have been abEe to make
this work with e fast computer and full
screen display.
I have alluded to the modes that
BMK-MULTY supports, so I suppose I
should give you some details. How
about fiTTY, CW, AMTOR and
PacTOR, with a standard demodulator,
such as the CP-i we have been talking
Amateur Radio Teletype
about, or a Hal ST-5 or ST-6. Flesh er
TU-170 or TU'470, iRL FSKOOOO,
Heath HD-3030. or even an okl honfie-
brew? There is ever an extended au-
dio package that includes an audio
spectrum anatyzer. with reception of
HF WE FAX and SSTV.
A "Logger^ modute includes a call-
sign and QSO database, whlcti oper-
ates within the communications pro-
gram. Captured callstgns that are al-
ready in the database are so indicated,
and a poo- up window is available to
enter QSO data as needed.
Mulli'Sampling algorithms jn both
the RTTY and CW modes are used, to
ensure the best possible reception un-
der the most difficult conditions. The
display can be configured to the user's
preference, whether a split-screen dis-
play with separate receive and transmit
windows, or a Simulated teleprinter,
v^th ali comtiined in one display. Func-
tions and featuTes are accessed with
function and ALT key combinations.
BMK-MULTY is the only commer-
cially available software that I am
aware of that implements AMTOR with
a dumb terminal unit. While using ad-
vanced programming techniques, the
program is capabfe of surpassing the
performance of compromise designs
within multi-mode controllers.
Another mode, PacTOR, combines
the features of Atn^OR and packet ra-
dio. Unlike straight packet. PacTOR.
which is highly effective on the HF
bands, runs at too or 200 baud, de-
pending on the conditions. With data
compression. PacTOR can achieve da-
ta transfer rates more than three times
higher than AMTOR. With handling of
the full ASCII character set, PacTOR
allows full text» and even binary, data
transfer, all with the lowest chance for
error.
Now, I have Indicated that BMK-
MULTY works wiffi almos! any ganieii
variety RTTY d^modutator. But what
about the ham who has invested in
a muUimode controller Many RTTY-
active hams no longer have an ST-6
on the shell Well, Schnedler Systems,
the source for 8MK-MULTX has pro-
duced an adapter board for the AEA
PK-232 which allows access ol the mo-
dem section of the PK-232, bypassing
the TNC and data processing logic
buifl fnto the box. While this might
seem like a step t^ckward. the truth is
thai for the modes that 8MK*IWULTY
supports, this reaJly does create an en-
hancement.
The adapter Itseff Is a small, "L**
shaped printer circuit board that is in-
stalled as a pass-through device be-
tween the PK-232 and the computer. A
short jumper connects to I he "external
modem" connector on the back of the
PK-232, and inside the PK-232. shwt-
ing bkjcks are installed to change the
logic of data ftow, A push-button on the
board sets things back to "nonrtaE" for
conventional PK-232 operation, such
as with packet
Now. you can order all of this from
Schnedler Systems. AC4IW, 25 East-
wood Road. P.O. Box 5964. Ashevllle,
North CaroKna 28813. The base com-
mufik:ations package, wt^lch includes
AMTOR. RTTY, CW. and the logger
sells for $95. The base package plus
PacTOR is SI 45. The base package
plus the extended audio package is
S140. And all three packages together
go for $175. The PK-232 adapter
board is S49. These prices are correct
as of this writing, and do not include
shpping. 1 would advise you lo contact
Schnedler Systems for cun-ent informa-
tion on phctng. shipping and availabili-
ty, letting them know, of course, that
you read about it in 73 magazine's
"RTTY Loop"!
Now, here's a follow up to nr^tehaf
we've covered tn recent months. I re-
ceived an E-mail message from John
Skubick K8JS via America On-line.
Jack reminds us that computer ports
are fairly standard. When looking at
devk;es such as modems. TNCs. print-
tfS. and the like, tf rt can pJug into the
seriat port of a PC-compatibfe ^Mmput-
er and work, than this same hardware
Should work as well on an AMIGA
computer, or any other cofnputer that
supports standard port pin assign-
ments. Thanks to Jack for that tip,
which he directed to me through Inter-
net-
And, while we're on the subject of
terminal units, here's a question re-
ceived via E-mail on Delphi: Emory
WA4TTO has been reading 73 maga-
zine Since 1976, Back in 197a or 1979.
he buit a DT-600 demodulator, by Data
Technolo0y Associates, from scratch
based on the documentation. He says
that it far out-performed any other
RTTY demodulator that he has been
able to construct. Since he lost Ihe
documentation years ago, and some-
one disposed of his DT-600 when he
was indisposed, he has been unable tc
duplicate the device, if there are any
readers out there with tnformation
about this denroduiator. we would love
to hear from you, as woukJ Enrx^ry, I am
sure.
A brief note about the growing col-
lection of RTTY programs available to
the readers of this column: There are
now five "RTTY Loop" disks, each one
holding over 1 ^ Mb of assorted stuff. A
list ol available pro^^ms is yours for a
setf-addressed, stamped envelope. 1
can E-mail you the list, as well. Jusl
send me a message via CompuServe
(ppn 75036,2501). Delphi (username
MarcWASAJR), America On-line (Mar-
CWA3AJR), or Internet (f^arcWA3AJR
@aoLcom), The plans are to upioad
the coliectlons. as well, to the Deiphi
Radio SIG delaiJed last month.
I've waited until the end ol this col-
umn to tool my horn. This month
marks the beginning of tt>e 13th year of
"RTTY Loop." I guess it can vote nowt 1
can't begin to tell you what il means to
get the support I have been receiving
for these many years. I fook forward to
your letters, your E-mail, your ques-
tions and your criticisms. I hope thai
we are able to spend more time togeth-
er in the future, to explore the wide
worW of digital communications, here
in -RTTY Loop."
I Don't miss a single issue of 73!. Call 1-800-289-0388 to order your subscription.
SPY ON THE EARTH
See live on
your PC
what
satellites in
orbit see
Capture five breathtaking images of the Earth for fun or
profit with our Spy Sal software and hartfware package that
does it all. Track, capture, display, zoom and analyze
imag^^ direclly from 6 or more environmental satellites.
Conplete Earth station packagt indudes an[erir>a, LNA.
sat&irii^ receiver demoduiaiof, A-0 con^/erter and software,
a'l for only S399 plus S25 shipping. For FREE irrfofnTalwi
log-on tQ our bullebn board anytime at: (718) 740 3911. For
iftformaDon by mail send S5 (includes derro disk},
VANGUARD Electronic Labs
Dept. A, 196-23 Jamaica Ave.
Mollis. NY 11423 Tel. 7 18-468-2720
JADEPPODUCT^ ^iC
MrrtvC WE J4U1* LRHAiac H
RO. boxstt
FAX 603-325-4499
FUIMUT AHTINNAS
IMTRODUCINO THE TWIN-LEAD WINDHAM
FOR 60-10 M BANDS 1NCL. WARC BANDS.
WINOOM HEAVY D UTY RU &&£ R MOU I^ED T W J M- LEAD
AHTEMKA WfRE SUPPORT 1^4' (41 w) LOMG COMPLETE
WFTH 50'<17 M) FE£D LINE OTHER LENGTHS
AVAIL USE WITH 1 4 BALUN (NOT llSkCi ) OR
TUNER AM-aO TWIN-LEAD WINDHAM XM.OS
AT.*I 1:4 BAUJN, HATCHES 500 TO aOQQ $22-00
EASY TO ASSE1«H.E TRiU TO LENGTH \
ADO COAX. HALF THE SIZE OF A P^POLE
TWm-LEAD
NEEDS m:j TUNER MAX PWR 7ClOW/$oa LADOCR-UNE-
AN'OI 1BQ METER ANTENNA t90,»S MARCO NJ
AN-)& eO METER ANTENNA %MM ^
VISA, MASTERCARD. CHECK ON MONEY ORDER ACC£PTED
USA Ship COST S5.00 FOft l5i t100: Si .00 FOR EA. A[i;A tlOO.
Series Mode
Powerline surge protection
♦ Effective- required protection for
interconnected or networked equipment
♦ Reliable- non-sacrifidal design
♦ Safe- Uses no MOVs
Award winning Series Mode teclinology
eliminates the destructive energy of surge voltage
surge cun^ent!
Calf or write for hjll details today. Ask about yoir liom
operator/ dub discount.
ZeroSune Ine.
944 State Rt 1 2 Frenchtown NJ 08635
eOO-996-6696 FAX (908) 996-7773
CIRCLE 133 ON READER SERVJCE CAHD
CIRCLE 26B ON READER SERVICE CAB0
73 Amateur Radio Todays July, 1994 49
Hamsats
Number 13 on your feedback card
Amateur Radio Via Satellites
Andy MacAltiSter WASZIB
14714 Knights Way Drive
Houston TX 77083-5640
The Digital Satellites
OigitaJ coinmunicalion via the ama-
teur-radio satellites lias been around
since [he early days of packet-radio
activity. Before ihe first ARRL (Ameri-
can Radio Relay League) Amateur
Radio Computer Networking Convene
tlon in 1981 at the National Bureau of
Standianjs in Gailtiefsburg. Maryland,
AM5AT {The Radio Arrtateur SateSlrte
Corporation) eamiarked Special Ser-
vice Channel (SSCs) on future fiigh-
orbit satellites for packet communica-
tfons. Dr, Hank Ma gnu ski KA6M, de-
signer of one of the first packet digl-
p eaters, was in charge ot setting stan-
dards for 8SC use. This came at s
yme when AMSAT was still recovering
from the loss of Phase 3 A in 1980,
which was to be Ihe first high-orfail,
long-tife ham sat, Phase 3A met a wa-
lery end when its Ariane Launcher
Med to achieve orb it.
Packet operation through analog
sataliiie transponders is comparable to
direct user'tq-user pacl<et procedure.
Earty tests were made at 1200 bps
(bits per second), but activity at 300
bps using HF modems was mqre reli-
able, due to the weak-signal r^tuna of
satellite commumcatior^s at the time.
The use of the analog transponder
Space for packet experiments was
never popular. The store-and-forward
potential of the AX.25 packet protocol
was not addressed via the analog
transponder system. A digipeater in
space, or some other dlgitar mailbox
setup, was needed.
At the 1983 ARRL Amateur Radio
Computer Networking Convention In
San Frarx:isco. Phil Kam KA9Q pre-
sented the paper "^ Modulation and Ac-
cess Techniques for PAGSAT." while
Don Connors KD2S presented the
"The PACSAT Project." Don^s paper
described the design goal of "total
global access by ali hams to a store-
and' forward packet message handler*
via satellile. He explained the need for
packet satellites and charactenzed the
on -board systems and technical pa-
rameters for the required equipnrenL
Phil's paper on modulation tech-
niques, when viewed with Don's, laid
down the blueprint for many of today's
digital satellites, from frequency selec-
tion to modulation methods. It was
Shown that a fonn of phase- shift key*
ing (PSK) would perform better thtan
standard audio-trequency-shift keying
(AFSK] on an FM carrier for packet-
satellite downlinks. AFSK-FM has ad-
vantages that include cost, simplicily
and easy Doppler tracking, but it has
some tradeoffs. These Include ineffi-
cient bandwidth usage and poor noise
performance. Today we have satellites
that use both types of downlink
schemes. All am in low earth orbits.
In 1984 when UoSAT-OSCAR^II
(built by the University of Surrey in
England) went to orbit, 11 canned tt>e
Digital Communications Experiment
(DCE) which provides a proof^f-corv-
cept test-bed for PACSAT work. The
experiment acts as a mailbojt in orttit
to try various digital communication
software and to provide data on hsrxi-
ware survivability, current consump-
tion and operational behavior in
space. Only a small numt>er ol hams
around the world are active as gate-
way stations through the DCE, but
others can rout© their messages
to these gateways for uplinking to
U-0-11. The concept not only worked
In 19S4, but Is stifi operational today.
Messages can sometimes be seen be-
tween telemetry frames on the
145.825 MH2 downlink at 1200 bpS,
When Fuji-OSCAR-12 was
ISiJnched in August 1980 from Japan,
hams had their Orst opportunity lo find
out what PACSATs were all about.
Whenever the ''J" (2 meters up and 70
cm down) digital transponder was ac-
tive, stations could access the mailbox
and ieave messages for hams next
door or on the other side of the world.
The system used FM for the uplink
and PSK on the downlink. Signals
were good but battery probiems made
continuous activity impossible^ After
only a day or two the system needed
recharging with corresponding down
periods and ioss of ail the messages
in memory. Even with these difficulties.
the open digital mailbox was an excit-
ing packet experience. Fujl-OSCAR-
20 was taunched in Febmary 1990 as
a replat^n^nt for F-O-12. F-O-20 also
has battery and heat problen^ requir-
ing some downiime, but il is quite ac-
tive today for those wishing to use an
orbiting dfgital maiEtx>x without special
software.
in January 1990 the first batch of
four IWicrosats were launched by an
Ariane rocket as secondary pay loads.
Tto new UoSATs were also passen-
gers. Sent aloft were UoSAT-OSCAR-
14, UoSAT-OSCAR-15, AMSAT-OS-
CAR-16. DOVE-OSCAR-17. WEBER-
SAT-OSCAR- ie and LUSAT-OSCAR-
19, Today A-0-16 and L-O-19 provide
1200 bps operation using FM up and
PSK down. Specfai PC-based, broad-
cast-protocol packet software Is re-
quired to communicate with these
satellites. W-O-iS, sponsored by We-
ber State University in Ogden. Utah,
sends images in a special binary for-
mat. D-O-17* sponsored by AMSAT-
Braiif {BRAMSAT). currently transmits
telemetry that can be heard on
145.825 MHz FM. A standard ama-
teur-radio TNC (Terminal Node Con-
troller) In conjunction with a computer
or terminal and an FM receiver can be
used to see the data and messages
from this hamsal. DOVE is also capa-
ble of speech, but has yet to fulfill its
potential, due to minor hardware diffi-
culties and software needs. Work con-
tinues on Dove's recovery. U-0-15
died shortly after launch and. atthough
U-0-14 is currently in commercial ser-
vice on non-amateur frequencies, it
provided digital hamsat chasefs their
first opportunity lo try 9600 bps com-
municaliorkS with FM up and down, us-
ing the broadcast protocol.
AMSAT-OSCAR-21 provided the
fliBt operatiortal German RUDAK sys-
tem. RUDAK is a complex RISC-
based (Reduced Instruction Set Com-
puter) digital transponder. It can be
programmed to accept uplinks of
many types ranging from analog voice
to high-speed digital <teta, with a cor-
responding wide range of downlink op*
lions. While it spends the largest per-
centage of its time in a voice transpon-
der mode with a downlink of 145.987
MHz FM. it has also sent packet
telemetry, WE FAX transmissions of
uploaded images, and prerecorded
voice messages A-0-2t is a part of a
Russian navigalior^l satellite and an-
other amaleur-radlo paytoad. RS-14,
The voice uplink to A-0«2I is on
435.016 MHi
Several other digital satellites have
been launched in recent years.
UoSAT-OSCAR-22 is used for 9600
bps operation as a replacement for
U-0-14. The majority of the traffic on
U'0-22 Is terrestrial packet mail for-
warding,
Kitsai-OSCAR-23 is another 9600
bps satelElte with the highest orbit of
the digital hamsats. This satellite was
built at the University of Surrey in Eng-
iand but was sponsored by the Korean
Advanced Institute of Technology
(KAIST). Files found on K-0'23 In-
ciude short text messages, utility soft-
ware, picture files, music (midi) files,
voice mail and even game prograrris.
If it's digital, it's probably been sent via
K-0-23. Kitsat-OSCAR-25 is atmost
identical to K-0*23p with a stlghtty low-
er orbit and more advanced hardware.
Both satellites have on-board cameras
for earth -imaging experiments.
iTAMSAT-OSCAR-26 Is another mi-
crosat-style satellite. It was buill by AM-
SAT-ttaty. It currently uses 1200 bps
with FM up and PSK down with the
broadcast protocd. It can also operate
at higher data rat^ when appropriate
software is checked out- 1-0-26 is fully
capable of the popular FM-up^FM-down
9600 bps format of the UoSATs and
Kitsats, In addition, a telemetry decod-
ing program known as TLMDCITA Js
available from AMSAT-ltaly.
AMRAD-OSCAR-27 was built by
Interferomethcs and the Amateur Ra-
dio Research and Development Co.
(AMR AD of McLean, Virginia) in th©
Washington, DC, area, it is piimarily a
commercial microsat with amateur-ra-
dio capabilities. Most daytime opera-
tion is ham-related as a single-channel
FM voice transponder with a 145.850
MHz uplink and 43aS00 MHz down-
link. It is capable of high-speed data
operation experiments and is used on
non -amateur trequencies as EYES AT
to demonstrate the usefulness of
store -and-iorward commerciat com-
munications with low-orbit satellites. A
telemetry decoder program Is avail-
able from the AMRAD BBS at (703)
734-1387 or via anonymous ftp
throtigh the Internet at ftpJunet.fi or
ftp.digex.neL
POSAT st^ 8 times called POSAT-
OSCAR-23. is a UoSAT-based satet-
lite from Portugal. Like A-0-27* il has
commercial uses and shares Its time
in orbit between ham and industry-re-
lated activities. It has been operational
on ham frequencies at 9600 bps.
Finding lUore Information on
DIgi-Sats
The unique types of digitaJ hamsats
in orbit reciuim different hardware and
software. It is Iseyond the scope of this
introduction to detail all the require-
ments. Fortunately, there are several
sources of information on how lo get
active via these satellites. AMSAT-NA
has several books and software pro-
grams to provide advice on how to be-
gin. The Satetlite Experimenter's
Handbook by Martin DavkJoff K2UBC
is published by the ARRL and pro-
vides good general information on
satellites with specifics covering the
amateur-radio satellites and packet
satellites. Decoding Telemetry from
the Amateur Sateflites by G. Gould
Smith WA4SX1VI gives in-depth cover-
age of telemetry systems on the ama-
teur satellites, with empriasis on the
digital hamsats. The Pacsat Begin-
ner*s Guide explains the methods of
commonicaling with packet satellites
ar>d indiides a disk containing the PC
software for the broadcast protocol
"Getting Started in Amatetjr Satellites"
Is a VHS video tape from CO Commu-
nications that covers all modes of
satellite operation and Includes
demonstrations of the broadcast pro-
tocol via digital satellites. Tracking
software is also available from AMSAT
for most types of computers.
Many articles in OS7; CO, T$ Ama-
teur Radio Today, Woridradio. QBX,
OSCAR News (AMSATUK) and The
AMSAT Journal (AN/ISAT-NA) have
been written over the last lO years
describing past, present and future
amateur- radio digital sateliites. The
January /February 1994 issue of TTre
AMSAT Joumat contained a complete
AMSAT Journat index compiled by
WA4SXM. Over 20 articles atx>ut digi-
tal satellites in a four-year period are
noted. The "Hamsats" column fn 73
Amateur Radio Today has featured
digital satellite updates several times.
Mote Table 1 for a current list.
Getting Started
There are several easy ways 10 get
started with the digital satellites. If you
have a Bell 202 style modem and can
modify it for mark and space bit inver-
sion, you can monitor U-0-11 on
145,825 MHz FM. The satellite sends
ASCII data at 1200 bps. The continu-
ous data and messages can be easily
50 73 AmalBUf Radio Today * July, 1 994
Issue Date
Rage
May 1990
46
June 1990
51
December 1990
81
September1991
54
October I99t
62
December 1991
62
Apiil 1992
76
July 1992
&3
November 1992
56
April 1993
57
June 1993
56
July 1993
64
Novenritffir 1 993
53
December 1 993
50
hiav1994
60
Topic Covered
Microsal and F-O-20 Enformation
Modems and Hamsat operation
Packet via satelfite
WEBER SAT ground-ststlon operalion
UoSAT'OSCAR-22 taunch
9600 bps modems and how lo use them
Piclure files on the digi-sals
Kftsat-OSCAR-23 pre-launch data
K-O-23 posHaunch information
Operating through K-O-23
Pre-iaunch data on K-O-25
How to work SAREX
P relaunch data on OSCARs 25-28
Post-launch data on OSCARs 2S-28
The fBtum of Dove-OSCAR-17
Tabte h Digi-sat '^Hamsats' coiumns in 73 Anrateyf Radio Today*
received, and even captured for later
study using a computer in conjur*ction
with communications software that
can work with the modem.
D'O-irs standard AX.25 packet
downlink is also on 145.655 MHz FM,
Power tevels ttom the satellite are typ-
ically 10 times stronger than U-O-n
and can be heard on almost any an*
tenna. Anyone who is currently active
on VHP packet can hear the signals
and see the resulting telemeUy and
messages on a CRT or other display
device. For those who can capture the
data to disk, programs are available lo
decode the data and display informa-
tion on the satellite's activities and
health. One program available from
AMSAT-NA for $20 is TLMDC-ll, All of
the data channels can be decoded
and GKamined with this program,
The Russian M/r Space station has
a paclf^et BBS (Bulletin Board System)
on 145.55 MHz. Like DOVE, the
downlink Is AFSK FM and is compati-
ble with a standard TNC. but is fully in-
teractive like a terrestrial packet BBS.
When the space shuttle lai<es
SAREX (Shullle Amateur Radio Ex-
periment) lo orbit, one mode of opera-
tion is the paci<el ROBOT The ckjwn-
link is 145-55 MHz, but unlike Mir. the
LTpNnk is different. Earthbound stations
musi transmit on 144,49 MHz to con*
necl to the SAREX TNC,
lbi)le 2 is a Tist of the digital -ready
hamsats- The list is not complete, but
Shows the phncipaE actrvity of each
satellite and typical frequencies of op-
eration. For 1200 bps FM^SK opera-
tion, a special modem is needed in ad-
dition to the usual TNC. conputer. ra-
dios and software. These PSK
modems are available from Tucson
Amateur Packet Radio Society (mo-
dem kit), PacComm (add-on modem),
L L. Grace Commtinlcations Products
(DSP umXj and others. For 9600 bps
activity, a htgh-speed modem is re-
quired, along with some modiftcattons
to the TNC, transmitter and receiver.
High-speed modems and complete
9600'bps TNCs are also availabEe
from TAPR (kit), PacComm (add-on
modem), Kantronics, AEA (DSP unit)
and L L Grace (DSP unit). Some de-
vices, fike the DRSI DPK-9600 TNC,
are much more rijfficuEt to properly In-
terface tor satellite work, due to their
emphasis on ten^estrial-style hardware
compatibiJity.
The Future
More digitai hamsats are on the
way. Some are based on the microsat
bus, like UNAMSAT from Mexico,
while others are being designed
around the UoSAT structure. Data
rates are e)tpected to increase to 38.4
kbps and beyond, and higher frequen-
S&tellite
Uplinks
Downlinks
Current Activity and Noti?s
U-0-11
145.825
435,025
2401 .500
1200 bps ASCII (Bell 202)
U'0'1 4
9600 bps commercial service
A<M6
145.900
437.051
1200 bps FSK/PSK-PB"
145.920
437,026
PB call = PACSAT-11
145,940
2401.143
PG call = PACSAT-12
145.960
D-(M7
145.625
2401 .220
1200 bps FSK AXJ25 data
wate
437,075
437.100
1200 bps PSK binary data & pix
L-o-ig
145.840
437.150
1200 bps FSK/PSK TB"
145.860
437.125
PBcal = aJSAT-11
145.880
PGcalULUSAT-12
145.900
F-O-20
145.850
435.910
1200 bps FSKyPSK AX25 B85
145.890
145.910
A-azi
435,016
145,983
FM Vckae transpofxter (se© text)
U-a-22
145.900
435,120
9600 bps FSK -PB-
145.975
PBnalUUOSAT5-11
PGcaH = LIOSAT5-12
K-O-23
145.650
435.175
9600 bps FSK -Pe-
145.900
PBcafl = HL0M1
PGcall = HL01-l2
K-O-25
145.670
436.500
9600 bps FSK "PB"
145,980
435.175
PBaaB-HLQ2-11
PGcall = HL02-l2
I-0-26
145.875
435.867
1200 bps FSK/PSK T8"
145,900
435.8^
PBcaU=lTMSAT-11
145,925
PG calU rrMSAT-12
145.950
A-O-27
145,850
436.800
FM Voice transponder (see teirt)
P^-28
145.925
435^50
9600 bps FSK "PB"
145.975
435^75
PBcalUPOSATMl
PG call = POSAT 1 2
MfH
145.550
145.550
1 200 bps AX.25 BBS
SAREX 144,490
145.550
1200 bps AX.2S ROBOT
Tabte 2, The Digital Hamsats'
(MHz) are sttown first All upHnk
current activity. Primary downlink frsquenctBS
frequencies Bfe sitnuftansousiy active.
cies will be more common. Digital
compression techniques and im-
mense sateliite on-board memories
will allow larger files and even dig-
ital full-motion video experiments,
PACSAT was only an Idea in the early
1980s. Today it has many forms
and has become the dominant 3ow-
earth-orblt hamsal Commercial and
government interest in small digital-
ready satellites has expanded dram at*
ically since the launch of tho mi-
crosats in early 1990. This has
caused competition for 'leftover"
space on launchers^ but can also be
seen as recognition for a pioneering
effort that was begun in the amateur^
radio community.
Handheld Repeater Controller
SiMClnjm Eledranic P/oduc^
frititxlijces ttie wofhi's first
handield repeater controllef .
Ha brgef tttan most handhekj
lacboa, the HRC-10 converts
a single or duaf-baixl radio
km a f^ teatured simpler: or
tb^itex repealer system Key
tealureis of the HRC-10 in-
duce voce I Der. DTMF Co^
trol and progTammifTg. hang
and time-out tamers. Digital
Voice Operated Squelch
(DVOS^), telemetry tones,
and ^rwme voce marl ^ot
Phone 4QB^3a-Z7ea
FAX 408-436-«027
S29d
Say You Saw It In
73 Amateur Radio Today
hambrew
FOR AMATEUR RADIO DESIGNERS
AND BUILDERS Q„^teriy
«20/yr.
Kllbtiilders
Tckmctn'
QRP
AcHnnced
Basic
Neophyte Rcvr, Roundup!
Packed With Projects! Not Sotd In Stores
S30A>.Canada & SUtko jaSA^r. Woridwtde
PO Bo\ 260083- 1 ^ewood, CO 80226
VISA*\fC: 1 800-5-HAM RIG
I
^ Ei^ ^^; ng, onlins awards ttackirtg, QSL
mariagcmsrit JactUty. Fad^o mrerfacjng, anterina
roior oontrot, data termirmi im alt d^gttal nrtodes.
unsquaded pac^tst spottir^. comesting. CW key*
er, sound csj6 sjpport. tuW mouse support
customtratiite scfBens and repciHs. SLperb doo-
umentstiQti and tech suppoft, QrBy3lr>e prapaga^
ticw cfiait iriterlace io ca^;-DK datBba&es, and
rruch more. Specs: IBM :s36SX, 4rT* RAM
hard dnve, LOGic 4 DOS S79, Wmtkms S99
LOGic Jr DOS S39. Wirxrows S49. Foreign
shaping extra. visa^iC- ^-'^'t n'-^p*jf' Also
availal34e: PDA QSL Route Ust. Radki Inter*
i»C* hardwargi. Keyer Interface hardwum.
MudDV Hidii Dr^ Duiuin. OA 3C13C PTi
404-^4 i-0M7. ftM 4<H-449'Efi£7 TbI^ mpp.
4El4-4t7-1A3i. 1-6 M-m S-noflti Rl
1
I
J
CIRCLE es ON PEAOEft SERVICE CARD
CIRCLE 2BB ON HEADER 3£I^VICE CARO
73 Amateur Radio Today July, 1994 51
^^ Numoer 14 on yoi
Carr's corner
Number 14 on your Feedback card
Joseph J. Carr K41PV
RO, Box 1099
Fsils Church, VA 22041
Dumping AM BCB
Interference
The AlVl broadcast band (AM BCB)
funs from 540 kHz to 1700 kHz. (You
fead right: The FCC raised the upper
limit ffom 1600 to 1700 kHz not long
ago.) Most stations are local, and rela-
tively low-power. A few stations are
farge regionals or clear-channe! 50,000
watt blowtorches. Because AM BCB
stations are largely focal thers are lots
of them, so it's a pretty safe bet that
many, perliaps most, ham operators
are close to al least one station. When I
was a recent graduate from Movice
ranks, a friend of mjne, the late Johnnie
H, Thorne K4NFU. lived across the
street from WARL in Arlington, Virginia.
The station operated with 1,000 watts
on 780 kHz. TTie fifth harmonic of 780
kHz landed right in the middle of the 75
meter phone bar^d. So what?
If you are any distance at all from an
AM BCB, there is practically zero
chance that a fifth harmonic will be
found. Right? Afier aH. AM BCB sta-
tions are regulated a lot heavier than
ham stations. While we need to keep
our harmonics -40 dB down from the
carrier, AM BCB stations are typically
-60 d8 down, or more. One AM BCB
engineer showed me spectrum analy^-
er reports from a consulting engineering
firm that showed the second harmonic
down -85 dB from the carrier, and the
higher order harmonics even lower. So
what's the big deal?
Weil, it seems that any time a strong
RF signal of any frequency is present at
the input of a radio receiver, it is possi-
ble for the signal to bust through what-
ever front-end tuning or bandpass filter-
ing exists to overbias the input device
(transistor, IC, lube), and cause it to go
nonlinear. In this condition, a harmonic-
free signal from the AM BCB station will
generate harmonics in the receiver.
K4MFU's station receiver at the time
was a late 1950s vintage Ham marl und
HQ-110 which, by all reports, was at
least a decent receiver, if not spectacu-
larly so. But when the receiver was lo-
cated only 100 yards from the WARL
antenna, it overloaded and produced
harmonics well past the 40 meter band*
The solution to the problem is to put ei-
ther an AM BCB high-pass filter in line
with the antenna, or to put a specific
frequency paratlel resonant wavetrap
(tuned to the offending station's fre-
.quency} in line with the signal line. Al-
ternatively, a series-resonant trap
across the signal line could be used. In
either case, the offending signal is at-
tenuated seriousEy
AM BCB Wavetraps
Two simple wavetraps are shown in
Figure 1, while a 'universal" printed Cir-
cuit board for these circuits is found in
rem
LI
220 ^H
C1
365 pF
(a)
frr^rfi/i/v\viMiVM-^yy;^^j^^
J1
ANT
e
LI
220 ^H
C1
365 pF
(b)
Figure 1. A) ParaHef-funed wavetrap, B) Senes-tuned wavetrap.
Figure 2, (These Universal Wavetrap
boards are available for $4 plus $1.50
S & H per order from FAR Circuits,
1SN640 Reld Court, Dundee IL 60118.)
The circuit in Figure 1A is parallel re so-
nants so is placed in series with the sig-
JUMPERS FOR SERIES RESONANT TRAP
INPUT
^
Ji
U^n^JOiiSflt iJRUETRfHf^
JU2 j2 _
m
o
o
o
o
OUTPUT
JUMPERS FOR PARALLEL RESONANT TRAP
I mi I^IIMIfflBMBM^^^^^^^ ,1,] ii,a,li,i»
INPU
JU3
J2
^.r-
^
9
OUTPUT
Figure 2. A) Printed circuit layout for Universa! Wavetrap: B) jumpers for series fBSomnt trap; C) jumpers for parallel resonant top.
52 73 Amateur Radio Today* July, 1994
nal line between Input (Jl) and output
(J2). This is done because a parallel
resonant circuit has a high impedance
to its resonant frequency, and a low
fmpedance to all frequencies removed
from the resonant frequency by more
than a little bit. Thus, your HF ham band
signal will pass through with little attenu-
ation, while the offending AM BCB sig-
nal is blocked.
The version in Figure 1 B is series
resonant, so It is placed En parallel with
the signal line. Series resonant signals
have a low impedance to the resonant
frequency, and a htgh impedance to fre-
quencies removed from resonance.
In both cases, we use a 220 uH sfug-
tuned coil and a 14-365 pF variable ca-
pacitor. The capacitor can be a standard
single-section "broadcast variable."
These capacitors are a little hard to find
In the USA (although not in England),
but Ocean State Electronics [POB 1458,
6 Industrial Drive, Westerly Rl 02891;
(401) 596-3080 (voice), (401) 596-3590
(FAX) or (800) 866-6626 (orders Only)]
has several offerings In their catalog.
Order No. BC-14400; it is a 14-365 pF
model.
The printed circuit board can be used
either with the off-board broadcast vari-
able capacitor or with a trimmer capaci-
tor and as many disk ceramic capacitors
as needed to achieve the required ca-
pacitance. If you elect to use on-board
capacitors, tfien r^ote that CI A Is a trim-
mer capacitor, while C1 B, C1C and C1 D
are as many fixed disk ceramic capaci-
tors as are needed to make the correct
capacitance. The capacitors selected
are the SG -series from Dig i -Key (POB
677, Thief River Falls MN 56701*0677;
{800} 344-4539). The SG-3014 Es a 10-
180 pF trimmer in most cases, not all
capacitor slots on the board will be
needed.
The inductor on the printed circuit
board coufd be a toroid inductor, al-
CI
1590 pF*
w
C2
950 pF*^
C3
w
15&0 pF* ^
J2
RCVR
I l-ra I f an ■ I q | .i-^^h l-«-l -I l->^l->4^H^1
* 2 - 560 pF + 1 - 470 pF
t - 680 pF + 1 ^ 270 pF
RgurB 3. Highi>B$s UltBr (1,900 kHz) for AM BCB sappressfon.
thougti the number of turns may prove
excessive (or sorne of g$ to wind. The
particular pattern, riowtver, Is for a
Toko-brand slug-tuned coif. In the Digi-
Key catalog, these are the 10 mm size
coils (e.g. 10EZ. 10EZC. lOEZH. etc.).
For example a Digi-Key cat. no. TK-
1223 Is a 220 jjH type lOEZ coiL
High-Pass Filter Approach
The alternate approach is to use a
high-pass filter between the antenna
and the receiver antenna terminals, The
filter should bB as close as possible lo
the receiver antenna terminals. In a
transceiver, ttie filter may tiav^ (o b% in-
side the rig's case unless, you have one
that pencils a separate receive anten-
The cfrcuil for the basic filter Is
shown In Figure 3; the printed circuit
board in Figure 4, The capacitor slots
on the printed circuil board are de-
signed for a variety of different types of
capacitor: disk ceramic, silver mica,
polyethylene, and other forms. Thaf s
why there are four sets of holes each
for 01 « C2 and C3. In most cases, you
will have lo mix and match the capaci-
tors lo make the desired values. The
.1S90 pF capacitors (Cl and 03) are
made from two 560 pF ar>d one 470 pF
capacitor: C3 {950 pF) Is made from
one 680 pF and one 270 pF capacitor.
The inductors could easily be loroid
inductors. A T-37'15 (REO/WKT) tofo*d
requires about 19 turns of enameled
wire to maKe the required Induclance,
As before, however, the printed circuit
holes are designed for a shielded Toko
coil (e.g. Digi-Key TK-1414). Builders
can buy the Universal High-Pass Re-
ceiver Filler boards for $4.50 plus SI .50
S & H per order from FAR Circuits (see
address above).
The components for the filter in Fig-
ure 3 are iniended for a cutoff fraquen'
cy of about 1.9 MHz, which means that
signals tn the AM BOB are attenuated,
hlowevef, Itie printed circuit t>oard and
basic design can be used for any cutoff
frequency desired fnom VLF to VHF.
Just caJcutate the values (or the fre-
quency you want to use as a cutoff.
The component values for tfie filter
were calculated using the "ANTLERS
for Windows" software. This software
podcage is designed to caknjiate anten-
na lengths, but has a Tuning Ctrcuils"
function in which one of the menu items
Is "Filters." Both high-pass and low-
pass cases are covered. "Al^m-ERS"
(sn be used to calculate the values for
filters up to 30 MHz, in case you want
to make one other than 1 .9 MHz.
"ANTLERS for Windows" Software
"ANTLERS" has the following func-
tions: HF antennas (3^30 MHz), VLF-
MW loop antennas (1 0-7,500 kHz), low
frequency antennas (500-7,500 khz).
VHFAJHF antennas (30-2.000 MHz),
and Tuning Networks (10 kHz-30
MHz),
Antennas covered In the HF functkxi
include: half-wavelength standard
dipole, folded dipole. inverted-vee
dipofe, G5RV. off^center-fed doublet
{OCFO), Windom. double-extended
Zepp, Franklin array, Lazy-H, one-
wavefength loop, half^defta loop, two*
wavelength bi^square loop, quarter
wavelength verticals, haif-wavelength
verticals, five -eighth wavelength verti-
cals, three-element yagl beam, two-eie-
ment quad^ phased vertical array, bob-
tail curtain, and Thome array. The
lengths of the elements and any match-
ing sections are included.
In Hie loop antenna !ufK:tlon, the pro-
gram calculates inductance of a loop oi
*A" side lenglh and "B" depth, as well
as the capacitance needed to resonate
the loop to a specific frequency.
Square, triangle, octagonal and hexag-
onal loop shapes are covered.
The low-frequency antennas func-
fion works lo 7,500 kHz, so it Is useful
to hams on 160m, 75.'80m and 40m. It
includes the simple dipole. the indue-
tn/ely-ioaded dipoEe {two cases: induc-
tofs at the feed point arid inductors in
the center of each element), the twin-
lead tee antenna (TLTA), and the kiad-
ed discone (or "dippy discone," as
some call ft).
In the VHF/UHF function, the pro-
gram calculates the element lengths
and matching section lengths (tf used)
for all three dipoles also used in tine HF
region (see alxive), quarter wavelength
verticals. 5/8 wavelength verticals,
three -element and six -element yagis.
and Iwo-element and three -element
quads.
In the tLining networks function,
"ANTLERS for Windows" calculates the
numt>er of turns needed to achieve a
desired inductance on a toroid coil
form, the resonance of an LC circuit
(when C is known or when L is known),
arKJ filtefs (LPF and HPF cases). It will
also calculate the component values for
antenna tuning units, or impedance
matching networks If you prefer, such
as inverted-L section, L-seclion, re-
verse-L section, pi-network and the
split-capacitor networl<.
in all cases, information Is available
for the specific type of antenna being
calculated. The program uses scroll
bars to input data such as frequency, in-
ductance^ and so forth (as needed).
"AfsnXERS for Windows 2.00' i^n
tje obtained from me for $30 poslpald
at P.O, Box 1099, Falls Church VA
22041.
Rgure 4. Pmtedawuit txyard for Universai High-Pass Receive Fitter.
Tlie World of Ham Mo
Callsign May 94 Database
nn- W^rldld H^iin Rwlisi CD-ROM iiiLliiiliis
the VCC amMsur £a]\ sign dittobMC. Sluh <iNi\'i
^^liMi US fuLm cuih in jiud tecondii wtlli
CAI l-$ICir^ A D-BikKe dnui nie W mIm)
I . W trw All yoia: sfUXii^ Oiqlkipn
. ^ jjHm iweiJH Vou wilt rcccivt the Ijiica
■ cMsi\ in him fadto ta/hwrnc jirogrimi
novrrifli 4ll iJe mmMeuT cmt§Bnf% rrom
-iipxnmp^ all nvc=r tl^ yktuid L#« CDVll^ W
^jidc \iMi whik ^KWiBi^ ovB 7JUI1> IBM
prDfnnt file«. cna iJDD ndn imd^ ind
vatncfipikm thee i\mes t, tern *n Mi>.
^ieyi*fi^. 4t immmy for i^ VS. SicJ9
s4 %X Owfntchi USA S!»^ f^ofrtf^ iiniMlf
\^. AmSvk. PO^Bai 666. W* Ctim^eft4lld.
PA I -Kmhimtf t'S A F A V: 7 1 7 9^B-bWT
AmSoft 717-938-8249
Actual Circuit Emulation
A better way than ICE!
• jVlcire pQvver wMh mudi tess cost
• llrivers far LCD,I>TiVfF«iiiore
•EjLteriiftI power lypply for
24 tfour 1 day opc'ratifin
• Rum; independently of PC
• Versatile Inlcrftce Adapter
oneBoanl, timplc ripansJan
• Board resjdcitl forth optkm
• i:se as programmable FCcard
• All sovrce Ef inctudcd, KemaL i
Fwrtli* PC DfiiUREer and >\ss?fflbler
• ClblcT Breadboard, Power suppJy
The eBoitrtl^
S1952S
tti^ilaEiflj fciJcctroaics
13720 i^kciihon Drivt
ncarLake. CA 115413
Pliaiie 707 994-1024
Fai 707 W4-5iU
teiuo]. ^i'lXi
Object Oriented
HardHnre-
M>?^ RC-1 000
computer REPEATER
Concepts CONTROLLER
• Autopatch • Reverse Autopatch
• User Programmable CW ID,
Control & User Codes & Timeouts
Manual with schematics * 90*Day Warrafity
Wired & Tested w/ manual ,.., $239.95
Micro CompLfter Concepts
BS49 Gum Tree Av«,
New Port Rlctiey. FL 34653
813-376-6575
CIRCLE 1 13 ON READER SERVICE CARD
CmCLE 43 ON READER SERVICE CARD
CIRCLE 1G0 ON READER SERVICE CARD
73 Amateur Radio Today * July, 1 994 53
Humber 1 5 on your Feedback card
V s nurnoer t a on your reei^
Hams with class
Caroie Perry WB2fAGF
MB(Mb Mentors, inc.
P.O. Box 131646
StBten island NY 10313<HXf6
Upl Up! And Awayl
When the Invitation first arrived to
attend the launch of the space shuttle
Endeavour's mission STS-59, I was,
of course, ecstatic for the entire first
weeic of April. There are few things in
life that are quite so exciting as watch-
ing th€ 122-foot'bng ort>lter lift off liKe
a rocket, orb^ like a spacecraft and re-
turn to earth Oft a landing strip like a
glider.
This invitation from Mlssiori Spe-
ctafist Jay Apt NSQWL was especially
exciting because I was atife to t>hng
guests with me. After my own two chil-
dren nose-dived across the room at
me for the invitations. I decided to
make this into an incredible opportuni-
ty for some lucky student in my ham
radio program,
I ran a contest for my slxth-^ sev-
enth- and eighth-graders. They were
asked to write an essay, describing
why they should be chosen to attend
the launch. Hundreds of children put
their feelings about the Space Pro-
gram down on paper. They were ali
wonderfuL ft was great to see such
enthusiasm. Usually, when someone
mentions thai they've visited a special
piace near Oftando. the other kids as-
sume il must have been Disney World.
One of my eighth-grade young
ladies. Ren^e Hoehn KB2QMR, was
chosen lo go, Renee participated Jn
last year's Ocean Challenge and has
spoken to several of the astronauts on
the CQ All Schools Net during the past
two years. She has expressed a keen
interest in all the space projects i do
with the chiEdren. Ren^e is considering
becoming an astronaut.
Both Renee and her mother Ellen
were in constant touch with me as the
big day grew near The entips school
got involved with our trip. Children
who arnnl even in my program were
stopping by to ask questk>ns atxjyt the
Endeavour's mission. So much inter-
est and enthusiasm was generated
that 3! really became a school "^wide
event. Long computer banners were
hung In the hallways, wishing us a
good trip. Ren^e became somewhat
of a local celebrity, and her eagerness
was contagious. She was only too
happy to share her expectations with
the ham radio operators she spoke
with on our school radio station.
The Launch
On April 6th we left for Ftorida with
the best wishes ol the student body
and staff of Intenmediaie School 72 in
Staien Island, NY. Everyone really
seemed to be proud that two repre-
sentatives of our school would be
there in person to witness this Spec-
tacular event.
The Endeavour had its share of
setbacks getting launched. On Friday,
April Q, we were up at 3:30 a.m. lo en-
joy breakfast together and to get over
to the Kennedy Space Center to see
the sun come up over the shuttle on
the launch pad. It was positively awe-
inspirir^g.
It was so incredible to be part of the
group of onlookers wfth cameras and
binoculars poised and ready for the
big moment. There was definitely
something sun^eallstk; atxjul the eaity-
moming scene. We even gol to meet
some media people from Germany
that day who were making a docu*
mentary movie. NASA and the space
agencies of Italy and Germany provid-
ed the $3S6 million mdar equipment
aboard Endeavour.
The sky, however was definitely
overcast that day. "Everything in every
direction . . Js solid overcast." Robert
Hoot'' Gibson reported from a weath-
er airplane more than an hour after
Endeavour was to have taken off. The
doitds parled slightly later, but as they
did. dangerous winds Kicked up
across a nearby runway where the
Pholo A. Left to right: Renee KB20MR, Mrs. Hoehn, CaroiQ WB2MGR and LOri
KA2TCC (Caroie's daughter), early in the mommg at the taunch site.
shuttle would try to land In case of an
emergency shortly after liftoff, ""It
would appear weVe traded one va-
gary for another," launch commentator
George Dltler said at the Kennedy
Space Center,
We listened carefully to the live
broadcasts over the speaker system
at Ihe viewing site. They spoke about
the t^ckgmunds of the six astronauts
on ticard. We listened especially at-
tentivety to tf>e plug for amateur radio
when they Spoke about Dr, Jay Apt
N5QWL and Dr. Linda Godwin
N5HAX, Jay is the Mission Specialist,
He is the Commander of ttie Blue Shift
and will operate the shuttle systems
during the "night" shift, while Linda.
who is the Pay load Commander, Is re-
sponsible for overall operation of three
large radars in the shuttle's cargo day
during the "day" Shift,
The secondary payload is Shuttle
Amateur Radio Experiment, or
SAREX. Nine different schools have
been selected to partidpaie in SAREX
forttirs mission.
Saturday nroming, Apnl S, at 7:05.
all conditions were perfect for liftoff.
Rente's mom said that the shuttle
seemed to "glow magnificently as it
lifted off into the sunrise. As the final
rocket boosters separated and fell into
the water, they looked like falling
stars," For days afterwards both
Ren^e and her mother said that view*
ing the liftoff ol Ihe Endeavour was
Ihe experience of a lifetime/
When we returr»ed to school every*
one was eager to hear about wtiat we
had seen. I commandeered Renee to
speak to several of my ham radio
dasses^ l smiled to myself as she de-
scribed the sounds and feelings of the
moment of liftoff. All the children want-
ed lo know what it sounded like.
Renee described 11 as being tike "mil-
lions of firecrackers going off at the
same time."
One of the many nice things about
being a teacher at a time like this is
that an incredible, out ol the ordinary,
experience such as witnessing a shut*
tie launch can be Shared wilh so imny
children. It adds a new meaning to
"show and tell.*
VHF UHF MICROWAVE
Transverters:
§ M, a M. 222 JVIHz, TOlSm. 902, T296, 2304,
3456.5760 MHz, IOGHe
Receiving Converters:
1691 MHz. 2400 MHz
Antennas:
Loop Vagls &02 - 3456 MHx
Run and Armys Yagis. 6M - 70 cm
Low Noise Preamps and Kits:
144 MHl' 10 GHz
Linear Power Amps:
70cm * 2304 MHz
CompcH^fits. Cable. Antftnr^a Relays
FfiEB Cafa^g Avaitatfe
DOWN EAST MICROWAVE
eai Otson W3H0T
RR 1.BoK£3tO
Troy, Me 04987^9721 USA
Phone (207)948 3741
Faji(207)9^8'5V57
HamCaU CD-ROM
U.S. and IntemaUonal Call sign Lookup
Nearly LOQO.OOO Usttnga
TTiousandi^ of Pub])i:! Domain Programs
Includes Clubs 6c Mllltaiy
Still $50. + $5 Shipping
&. Handling per Order
Works on PC and Mac
Buckmastcr'a HarnCall CD-ROM looks up
calis in seconds. U.S. calls can be searched li^' any
efcmcnu intltiding name. dly. state, etc. A TSk is.
tDdiuktl to look tip ealteigns from aknosl any itJtt
appUcaUion. Pnnt* labf Is, No haid dljsk required.
c%-eiytlUng Is on mw CD-ROM! New CD-ROhf dwc
€v*jy April and Ociobcr. vith updati^ Ibttnga and
doaoM of new iiiuttj^iti!
QUCKMASTER
Publishing
RL 4, B6X LdaO-Mlneral. VA 213 1 IT
703:SS1 5777 800:282-562^
CIRlCue S6 ON READER SERVICE CARD
Do you use a
JURASSIC KJi
then fasl fbrw;ird lo ly"4
■ Add A Digilal Voice ^3
Messaging Sysicni To *Q*
Your Repealer -^^
• Leave Voice Messages For Each Other
• Get Packet Cluster Info In Voice
• Schedule Voice Announcements
• Computer Board And SoTuvarc $259
Call Toll Frv For Info Package
1 -80(^56:^-535 1 Toll Free From USA
1-I06'7iil-U5l Dffcct
DIGITAL Communicdttons Inc.,
Gi?nDral Delivery, Pitot Butte, SK, Canada SOG 3Z0
CIRCLE 1B1 ON HEADER SERVICE CARO
54 73 Amateur Radio Today • July, 1 994
Humber 16 on your Feedback card
MiClwef Brym WB8VGE
2225 MayfhwBf NW
M^ssHion OH 44646
More Modifications
If the DX is not running and the
bands seenn dead, what do you do?
Well, you could do Wke Scott NSJSK
does and raise aphlds. or you couJd
heat yp the soldering ifon and make
same modHicaiions to your equipment.
Ttiis monlh Tve got several m<xjifi-
cations for you. The first deals with the
very popular MFJ QRP rigs.
mj QRP Rigs
The first production run of these
nifty fittle rigs suffered from low audio
gain. The poky LM3S& audio power
amplifier was again pressed into use.
In the MFJ 9020, the LM386 is sup-
plied wrth its operating voltage from
the rig's main voltage regulator. In the
case of the 9020, ihe regufator is an
LM317. The output of the regulator is
Sdi for 10,5 volts. This is the voltage
the rig runs on, with the exception of
Ihe final RF output transistor. Since
the audio amplifier is also tieing pow-
ered by the 10.5 volt VCC, fts output
runs lower than usual The fix is sim-
ple. All you have to do is rewire the
Low Power Operation
VCC run so the L^366 ts supplied by
Itie unregulated side of the LM317.
The e>ctra 2 volts or so really ma*c^
an improveffient in gain.
Don't try to adjtjst the LM317 for a
higher output — you'JI screw up some
of the other circuits that require the
10-5 VCC. Also, since the LM317 re-
quires at least 2 volts over the regular
ed output. yOLj'll lose regulation of ttid
VCC tine. Figure 1 shows hiow simple
this is to do: Cut a trace on the PC
board and run one wire. Thai's all
there is to It.
MFJ made this modification to later
production runs Of the ngs. If youVre
not sure rf yours has ttie modir»cation.
check pin ^ of the LM386 with your
VOM. If the VOM says 10.5 volts, then
tt>e nxKliflcation has not been ddne. II
the VOM reads the suppJy voltage,
say 13 volts, then the modification is
factory -installed.
New Front End
Atthough you can1 reaJty can this a
modifrcaljon, the cirouits shown in Fig-
ure 2 may improve the performance of
your receiver. The values are tor the
40 meter band. The circuit at the top
seems to work the best for me. Id rec-
ommend It over the other one. but
rtnlwnna
ToMur
CI C3
C2 100T9F
To
L3.. 34 tUf1»
j^rr
&igte ««wd 40 ir«v bom wd
Unt-es^ecn
fiSgwne 2. Two circuits that might be afc/e to improve your receiver's front er^d. Val-
ues Bhowf) are for 40 meters^
TP2
DC input 13 S V Pummt
0
uutaae
Before the modification
IPS
0
In
U017
Acf]
Om
I ^^^1 —
1
>
10.5 votts
to nasi
22
jAnarinoctticatiofi
=^
Out
LMsea
Egi/m t. Modification to correct tow aucfio gain in some MFJ QRP f^igs.
that. too. works quite well. Use the
cores specified fn the schematic. The
variable capacitors are Arco trimmers.
1 used hamfest junk boK units In my
project
For transceiver operatioa you must
break the connection between the
receiver and the transmitter Insert
the filler In the receiver's antenna
line only. If your transceiver has diode
switching, with a pick-off from the
transmitter's output filters, you may
have to pfay with the values of the
filler's components. I find this circuit
really keeps the unwanted critters
out of my direct conversion receiver.
ToR3
A
Switch R3 before
modification
■^- Coax 'narrow'
Coax '^ide'
ToR3
I
Switch R3 before
modifk:ation
Coax "narrow*
BANDWIDTH COhJTROL
Coax "wide"
Figure 3. A modification for your Heath HW-9 which wiU repface the selectivity
switch with a pot
73 Amateur Radio Today • July, 1 994 55
Although ! don't have one In my
shack, I wonder If either oJ these filters
would make the Heath HW-7 receiver
worth using? Again, yoy would have to
break ihe connections between the
transmitter and the receiver. This will
require cutting some PC board traces.
Donl try It if you're not up to this type
of modificatjon.
No matter how you use these fit*
ters, they will work best if you install
them In some sort of shielded box. I
use double-sided PC board for my
boxes. BuIh the stuff is really hard to
get into if you solder all the way
around the edges.
or rtmy not like the results.
The second modification I urns the
S-meter into an expanded voltmeter
so you can track battery voitage. This
is a great idea it you're working on
battery power In the outback. This cir-
cuit is also from Germany. The
schematic for thts modification is
shown in Figufe 4. Notice the values
of the resistors. The values lisled are
only a gukje: you will need to change
the vaiwes to suit your HW-9, Seems
Heath did not use Ihe same meter in
all produciion runs.
A doyble*pole doubte-throw switch
selects between S-meter and volt-
'Wo matter how you use these filters,
they will work best if you install them in
some sort of shielded box, "
A mtiftt-pole switch could be used
to sefect the proper front- end filter tor
several different bands. All the fiiters
wouid need to be shielded from each
other in one box. Again, doub^e-slded
PC board is qmgx k)rfhis.
HW-9 Mods
Here are two more modifications
for &ie Heath HW-9 QBP trartsceJver.
The first one is rather simple and
IVe seen this same modification done
to the iHW-8, ft requires removing the
seEectivity switch and replacing it with
a pot. In this case, the switch Is
replaced with a 22k pot. Since this
modificalion came from DL7GK in
Germany, Td say you could get by
with a standard 20k pot and have the
same effect as with a 22k pot, 8y us-
ing a miniature pot, you might be able
to squeeze it to fit on the front pan^l.
The circuit is shown in Figure 3. It's
about as simple as they come. You
may want to hard-wire this modinca*
tion tn and give it a try before you
drill any holes in the HW-9. You may
meter. The entire circuit can be built
on a small hunk of perf board. A PC
board couid also be drawn out, too.
Motice the use of the meter scale. This
way, you don't have to recaiibrate the
meter and you don't have to rework
the meter's face. Take a look at Rgure
4. You'll see what I mean by using the
meter's face to read voitage. Nope, it's
not a fluke 77. but it's better than
nothing. And- you don't have to carry
another pfece of gear with you when
you travel.
Since I have sold my HW-9, I can't
say if either of these modifications work.
Proceed oti yoyr own with ca Jtk)n!
Longer Columns
Thanks fn part to my new toy. an
Apple Powerbook, I've been able to
expand on some of these columns^
Having the computer with me at worit
has aliowed the column to grow a bit.
Since 1 work in a factory, the extra
time between setups has proved very
useful. That's why I've been able to
make these columns longer.
12VDC
11 VDO
13VDC
HW-9 S-^iieter face
6K
Red wire from
PCB (meter +) 4-
4.7 Vort
-^ V\A— I
Brown wire ^
ffoiTiPCB
(meter -)
WV^T — w^
4K
5K
To -1-12 insfd©HW-fl
Figure 4. Schematic for modifying the H&ath HW-9, turning the S-met&r into an
expanded voitmeter so you can imck battery condition.
Damn, It's Coldt
n*s ookJ up here in the mWdte bay
crane! Yupl This is January 19 and rfs
the coldest day on record. As i work
on this column, all the major electricity
suppliers have asked heavy industry
to reduce their electrical demands. In
fact, our factory has been ordered to
shut down so the energy can be used
for residential customers, tn some
parts of West Vtrglnfa. there have
been rolling blackouts for up to one
hour
If you happen to enjoy running
QRP, you'll never notice the biack*
outs! Why. an HW-9 or a MFJ 9020
and a battery wtil keep you on the
air for a very, very long Itme. Thafs
especiariy true if you don't smoke
ctgars!
I
I
I
I
The Only Material That Will Adhere to^
Polyvinyl or Vinyl Outer Coax Jackets!
I
I
I
f orm^ moyrtd and seals
odd-shaped fittings.
l^ot^'Comaminiting and non-
coiidyctiv«,
WKff amtiientltmfjeraiure rangq
Stiys flexible for years insuring
moisture *pr oat con necti on s .
F!eLJsable^tjickdiscQnF>ec:1[on
and reseaiJng with sama rnalerial.
AmustforsateliileTV—
microwan/ewarL
Hun<lrad$ of uses-
Moistu reproofs all connedions.
V,
CO^XSMt . This
tpacit-r«ijp niiift'iil II
OF plaitlc. Wrtp 10 i</vt<
toward lllllno. A1t*r
wrap^n^. nKld H lorm a
anoDth iilftAit Jind brce
□uti-r
EFFECTIVE
MOisrunEPflocff
I
I
I
EVERY LNB AND COAXIAL
CONNECTOR NEEDS COAX-SEAL
^Trialpacketfor4connectors-S1.ooppii.j
UNIVERSAL ELECTRONICS. INC.
4555 Groves Road, Suite 13 Columtnj?. OH 43232
Phofie (614) aaS-4S0S • Fait {&\4) 866-1201
CIRCLE 32 ON READER SERVICE CARD
56 73 Amateur Radio Today • July, 1 994
SELL YOUR PRODUCT IN 73 MAGAZINE
CALL DAN HARPER 800-274-7373
ATV CONVERTERS • HF LINEAR AMPLIFIERS
OIlCOVfR THf WCRIO OF
FAST SCAN /dk ^TfitVlSIOH
net* .
HP JWtPUPiEiS »m WO TOKO LA BUlLlTUli
13 CM
AN HI l«VW I n.2i
ANrrtH »w i 9}.tf
ARltS 3WWIU3.AO
1011 l4tW t It IS
NIWIJ' IK WATT 1-ig^MMtAmplWkff
Mb4rt K H«>1 !&hnb(|.|j1 }»I «) „...
CHS -6 Cofftf 3pri>*n|«s6il/4J .
Ww fl^ie iLHh Harris la -^Irid pmit
AMATEUR -Ff LtVISiON COWVEHTEHS
POWER 9PLirrEtt$*nrf COMBINERS
l-19MHt
ATV) 470-410 EGaAS-FET} t 40.«S Kk BdO W^ti PfPI-l^wi. „„.„„! 19 M
ATV* H3r-t31 jCUAS-FET\...,....t Mt! KH IMO W*tt PEP I-Pwt ...t ri,»
\ tit Wwtt PEf 4- Part . „.l nM
AUDIO tOmiCIt COilTHOt fa* ATV
S(l . "'■" „ ,, — .„! M.«lCiC I M Vr * T T i Jt - 4ia MN J PUSH ^PtJ LL LIH EAJI
J METCai Wwf AMPUFtEMS
31 Wrtt M9*ti IISA.-^T:!"^. |?««SK.i im«T-#a«ut|. ,.,,. .......„.„, tl»ft
Ji Will **miut ITIA ttlSJli K^ KMttr-nsm 9C Im m -^- S l^M
AvHtaUt in luA M vif<M/t*«4#i SEHf^l |MiMri4 ---"ii*>*-->'>4> t 1.44
CHIP CAPS-Kfrml/ATC
M£TALC LAD MICA CAPS^ Uii>k*/Safn«d
nf POWER TRAN9JSTORS
MINI^CIRCUIT MlJtERS
• «.M
• T.«
ARCO TRlMMtJt CAPAtiTQM
VK7<F9-3t/4SMP Ch«di« ,.-^_ • 131
KP Tfantfi
sei-i h-i«4Wii
S6L-]i |»-]H«Mil
AM 1 1 Jl tmt ilMHi^g bM
'^•.
'<n-/a
CCI
Communication
Concepts Inc.
(Sn) 426-0600
&0E MUUloni Drhrt * X«ni>, Ohio 4Sia5
FAX5l3~42»-3ai1
H^^5iBtJ ^
o*^
0^
^t- ^vO^
CIRCLE 99 OM READER SERVICE CARD
TIRED OF PLAYING G4MES?
Rnaly, a practical use
for your soindcanl!
Passband
Signal
Btid tuning
surface
plots
iCOlOt
Spectrogram
track
freqmncy
changes
over iime
Multiple open windows
Spectra Vision & Spectra Plus.
Real-time audio spectrum analyzers. Full control
over FFTsize, sampling rate, scallrjg, gain, and
averaging. Requires 386 or better, Windows 3. 1
and any Windows compatible B or 16 bit soundcard.
"-A stroke of brltliance...B grourrdbreakfng and
valuable program/'-MonHoring Times
"-Knock-your-SQcks-off qualityt"- Harold Privo,
QEX Magazine, Dec '93
Spectra
Plus
'^'■T'^'**
Spectra
Vision
Modes
Real time •
RecofHef
Post process
PncB %9^
All display fbrfnats included with e^ih^r package,
SO day rmsney-tvack giFararttee.
Aiso avBitsth: PF Vt&km'. Ask us abo^Jt H!
800-401-3472 ^x/vo^^e 206^97-3472
Visa. tJasterCard Check or Money Order
PkMiccr HID Software
2446Q Mason Rd Poufst>o. WA 9B370
S&M /fjcfwded, hreign d^mry add $10.00
Demo d%sl( $4MQ (crsdit toward purchase}
^ Austis^ IC T9dw€togfK
PO Bdy 50. Dym CwmiQ NSW 2429. ^6f ^50^22m
h Swedm: PICS Ciifp^9tfon
PO Biff 37, 440 4im.*46 30342995
CIRCLE 31 \ ON HEADER SERVICE CAflD
riph^ Power Packs for Longer QSO Time
FNB-26 V.\ESU lOOOma
BP-84S ICOM iMkaa
PB-7S KEWVOOD 14D0iDa
EBP-24S AUNCO laOOma
$60,00
S 63.00
$59.00
S 62.00
fikmufOiUm. Bin ttie
One Year Wamntv
Matdied ceD construction
Case rebuild semoe
Long lifc, extended opeiaiing time
Macfe for RAMS, b}' HAMS
Add ROD Shipping & HaiKJ^ngferfiBtbattey.
S LOO fgr each acid 1 batten" - \LS. an^
QxtnedKut re5HiQm^6%tax.
jiiaBMi
Avaikibk
(mm yotif
the only fhing !ow about our charge is the cost...
1^00^34^132
115-lB Huriey Road • Oxford, CT 06478 • (2(B) 264-3985 • FAX (203) 262^943
CIRCLE $Q ON HEADEH SERVICE CARD
BUY AMERICAN, BEHER PRICE AND QUALITY
Hie SGJDOO HF transceiver Is type accepted for coiTKmerclal and marfne servica
made wiih ifadilJonigl U^S. cflmmercial radio quality (and of course H C3n be used
on iho hem bai^d-s also). While Ihe Japanese radios have 2 Tnal transistors Ihai
fltfaiTi 10 put out too watis on tho low li^tnds and only 75-35 wans on len meters.
(fio SGaOOO tias 4 larQe iransJaiofs ihat loaf along at 150 wattfi ort AU. THE
BANDS (MCLUDING TO METEflSI Some o( the SG2000 features are: 1) A
cotilToi head rem stable (no special kit necessajv) up lo 150' away Irom Ihe rig,
pg^r'i^ct lor aiflornobii^^ and boats. iJp to B heads can be utilized and used d&
intercoms also. 2) TMe largesi display ol any HF transceiver. 3) 614 pre^
programmed memortes arid 100 user pfQgrammatii& memories. 4) opafabie (rom
-50F i'AbC) to re5F (+85C). You wanj quality righl? Hera Is what EVERY
SG2000 rrujal endurg before they're shipptjd frfim me faclory: 1) They're laclory
allQnod, a) EVERV SGMOO ts keyed down al lull pow&r (CW 1&0 Walls) InJo en
Open anienna lor at>out 1Q seconds, then connected to a srxorted antenna and
hayed down lor an ad^iilional 10 seconds. 3] EVERV SG200D is pul In thft
-BUFlM'lN" rack and keyed dovm tor 24 tmurs non-slop at ful! power CW. Don'l try that with the foreign radios. A) EVERV SGSOOO te
ltT4Sn ne'Che^hed fOJ" ai^^^^mem snd pui In (he 'TORTURE RACK" lArtic-^e they are t<eyed on and off every 10 seconds tor 2A hours. S|
The SG200CI is then reHjvaluated and all control functions are verified to ensure Jhat the microprocessor is up to spec, THEN AND
Ot^LY THEN IS THE SG2000 ALLOWED TO LEAVE THE FACTORY.
Ihe bottom line is price, you Know how expensive comnneftia^ ngs are normatiy. we are seinng the SGSOOO BELOW DEALER C0S7
ai oriiy Si 385 .00 each!! Thats a S400-00 savir^gs' We gusranlee the besi price.
j^DciSfpfoj?
Tilt SG23€ SMART-TUKER is Ihe best HF aulorjnef at any price, ant^ Jo
promole a pn>dLJCt D^l is rrade m itte USA, we re oiretiTig It al the duaranleed
Iwsl price of onty S449.00" WHY THE 50230? BECAUSE: When you ttine an
antenna fil irs base you are resonsottig me antenna, instt^ajd ^ pst matchmg the
coax lo *m racso as vtm other funeis such ss tm AT50. etc. Tik nesutt VQUfl
SIGNAL GETS OUT MliCH BETTER. T>ie Kenwood ATSQ. AT450 and other
stmi^ tuneti can of^ ma^h 2-.\ m$mzidhes fVES only ^^SQ forgei maich^
anylMns Dul a fairty (Secent anfeona, Ihe SG230 can match tnarm O.S Otni lo 10
iciotwn ahl>ervia£ (up to a 200: i misniajch). so it can eas^ matcn random iMlf««.
dipola. rttifvgiutlH^ shopfwg caits, OIe. The resuM MOflE POWEH.
To erder. mm check or morwy oidtc wfh mSOtot st^i^af^ dlen^ iiib your shppif^ acbtiB} (aviy m US Pvm
Ollict Bok«%. UPS mfd nod dr^vr) and TiJaphong nuiriifrtD:
Joe Brancato
THE HAM CONTACT
PO Box 3624, Depi 73
Long Beach, CA 90803
CA ncMkjnii Add i 1^4% S«I«T«il AlHia Hatt^an. and Canatiui Restlems pl^se send \J S MonoY O^
T £17.101 Jbr ahfipng.
Sefvmg Ihe LQfiD W ythJ wisft mtwe rniJwmatlon p'easc sefid a SASE to ihe above address. For COO onders. calf
Slic« 1987 t310)433-&e60, Qui^Jde oJ GA Orders Only cat (6CM}]Sa34iAM4 and leave a message.
CIRCLE 384 ON READER SERVICE CARD
73 Amaleur Radio Today* J\j\y,\B94 57
Ntitnber t7 on your FeedbacK card
M^k ntnnaer if an your reeaDacn ua
Packet & computers
Digital Amateur Radio
Jeffrey Slomarj N1EW0
c/o 73 Magazine
70 Route 202 North
Peterborough NH 03458
OK* Tm back after a month's ab-
sence. The cofumn tried to compete
with moving and losL Moving is one of
my least favorite activities, and this
one was worse than expected. On tfie
other hand, we're here and things are
smoothing out.
This month 1 have a few things to
deal with, so I wiii not be doing a "reg-
ular" instaliment of the TCP/tP series.
instead, I need to cover some '■admin-
istrative" information, and f'ii also dis-
cuss some iP odds and ends that
should be interesting.
First, the administrative, Uar^y of
you write to me, both on paper and via
the bit stream^ I really appreciate hear-
ing from you, and read everything. Re-
plying can ba somewhat more difftcuil.
i am not ignoring you. First, I get Email
from my other writing work as we if,
and tine combination of 73 mail (you
guys aren't shy), and other traffic can
be overwhelming at times. 1 reaily ap-
preciate all of the feedbacl^— praise
and not-p raise— but t just don't have a
good way to repJy to everyone.
Second, many of you have written
asking for reprints and execu tables. I
cannot provide these. Reprints com©
from 73— cali (603) 924-0058 to obtain
these; reprints are $3 per article ^ back
issues are $4 each. For the executa-
bles, I do not have the time to copy
and maii disl<ettes. I\flany of you have
sent prepaid diskette mailers and
disks. I have not been abEe to do any-
thing with these. You can get any exe-
cutabie or text file I describe on the 73
BBS at (603) 924-9343. 300-2400
baud, 8 data bits, no parity, one slop
bit.
Now wait a minute— I know that
many of you have tried to find these
files on the BBS and they just haven't
been there. I must take the biame for
Ihfs, but 1 will be changing It.
Now, a personal note to an un-
known reader: II you sent me some
cash, please write again and iet me
know who you are. You can identify
yourself by teiling how much you sent
and why. Some time ago. a bunch of
mail that included a collection of
checks, diskettes, and mailers got
separated from the letters that went
with them. I do not cash checks sent
to me, and I want to return your
money,
OK— Here's the last bit of adminis-
trative nonsense: how (and how not}
to contact me. 1 can be reached three
ways:
1. Email on the Internetr This is
the preferred method of contacting me
and stands the best chance of getting
58 73 Amateur Radio Today • July,
a response. Those of you who sub-
scribe to online services like Com-
puServe, Genie, AOL, Prodigy, BIX,
Delphi, and the like can all reach me
at this address. The exact method can
vary considerably— get help on your
system in addressing mail to the Inter-
net. My Internet address is: jslo-
man@bix,com.
2. Paper Mall: This is an accept-
able way of contacting me if you do
not have access to electronic mail
(you should ^ you know). Please write
to me c/o 73 magazine, at the address
listed above.
3* Packet Mall; Of course I want to
hear from you via packetl But, I cannot
answer questions about the cotumn or
magazine this way. Too many of you
write to me via packet radio and ask
things that, were 1 to answer, would
constitute doing business on the radio.
This is */erj/ frustrating: You have good
questions. I am no Mg no ring you, I just
can't answer — sorry. Please send me
packet traffic for fun, to try it, to let me
know that youVe got something work*
ing. But if you want me to respond,
don't mention the magazine, please.
So, with that preamble, address your
packet traffic to me at:
N1EWO@N0ARY.#NOCAL.CA.LJSA.
NOAM
{Note the NOAM at the end — for
North America. Do not use NA, the
people in Namibia are not too happy
with the folks that do>)
On to other business, Firstp lei me
tell you about the latest, and last DOS
version of JNOS: 1.10c. WG7J has
announced that he is now concentrat-
ing on developing a WIN32 version of
JNOS (a very good thing indeed), and
so UOc is the last version that he will
release for DOS. Where can you get
it? Well, as of this writing you cannot
get it on the 73 BBS. You can get tt via
anonymous FTP from several of the
ham archives. I will avoid specifying a
site— this has gotten me in trouble in
the past. You should be able to get it
from places tike CompuServe as well,
but I can't guarantee that. JNOS is
very widely distributed; ask around.
Version 1, 10c adds several fea-
tures which wit] be completely new to
those of you who are using non-re-
lease (x) .10 versions. First, there is a
very useful status bar which displays
using the top three lines of the display.
It offers some nice at-a -glance info:
On the first line — time memory sta-
tus number of sessions using the vari-
ous sen/ers (conv, tinks, bbs, fwd, ftp,
smtp), a list of active terminal ses-
sions, specified by number; these
bfink when tin ere is text waiting in a
session not currently displayed.
On the second line is a list of cur-
rent BBS users by callsign. Each cafl-
1994
sign IS preceded by a character Indi-
cating which activity the user is en-
gaged in,
On the third line is information
about the currently-displayed session,
including the connection and informa-
tion about retry timers.
(Users of Wf^JOS are already famil-
iar with this type of status display. This
excellent feature is now available to
JNOS users.) The status display is
configurabte in two ways: color and
number of lines. The specific colors of
the text and background of each line
are configurable. You can also choose
to display one, two or three lines ot
status information. Speaking of color,
the text display colors are now config-
urable at startup as well. This is very
useful because of another new fea-
ture— a command line in the trace win-
dow.
You can now execute commands
directly in the trace window. This is
very useful, for exampfe, when testing
using ping. You can ping a station and
see the interaction from the very be-
ginning. No more attempts at light-
ning-fast switches to the trace window
with thie F9 key are necessary.
There are many other features you
will find useful in this new and last ver-
sion. Get a copy and give it a try —
tests here show it being very stable.
TCP/IP Routing Using Diglpeaters
You and a friend want to communi-
cate using JNOS on each end; the
trouble is, you need to use a digi to
make the connection, a digi that
doesn't know anything about TCP/IP.
Hmmm, how can you make the con-
nection?
The impossibility of using a plain-
old-digi for TCP/IP is only a misunder-
standing of how the system operates
on amateur radio. TCP/IP over ham
radio has two different layers, There is
a logical layer that handles TCP/IP
messages and traffic, and then there
is a hardware layer. It is m this hard-
ware layer that the digipeater lives.
When you attempt to connect to a
friend^s station which can hear you di-
rectly, the first thing your station witl do
is to send an ARP request over the
default Interface. ARP means Address
Resotution Protocol, and Is the way
the an IP station finds out the hard-
ware address associated with the IP
address which it has been told. Let's
see how this works:
You type leinet 44.48.70.22" at the
JMOS command prompt. JNOS re-
sponds by opening a new session win-
dow. At the top of the window is the
message "Resolving 44.48.70,22,"
JNOS has Just transmitted and ARP
request. This is a broadcast message
saying, "I need to know the hardware
address associated with the IP ad-
dress 44.48,70.22."
Your friend's station recognizes its
address and responds, saying that
N1EW0 handles IP traffic for
44.48,70,22, Your station places this
information in your ARP table, and es-
tablishes the connection.
This is the way that it should work,
if stations can hear each other. But
what if they cannot? In this case we
can1 rely upon the automatic ARP pro-
cess, and instead have to make it hap-
pen manually To do this well need to
make our own arp entries^ and also
add AX. 25 routing information. ARP
entries are soft; that is; they will go
away v/hen you restart JNOS. To make
them "permanent," put them in the AU-
TOEXEC.NOS.
Here are the facts about the station
we wish to reach:
IP address: 44.48.70.22 hardware
address: M1EWO
(note that hardware address-AX.25
address)
digipeater: KB9BWE
So first let's make the ARP entry so
that the station does not have to gen-
erate an ARP request which could not
be answered. We do this from the
command line, using;
arp add 44.48.70.22 ax25 niewo dsp
arp the ARP command for
JNOS
add tells JNOS to add the
following information to the
ARP table
44.48.70.22 the host ID otthe station for
the entry (this coutd be
alphanujneric
[e.g.: N1 EWO) if you have
the appropriate entry in your
DOMAIN.TXT file)
ax25 tells JNOS to use the ax25
hardware layer
n 1 e wo th e h a rd ware address of
the station for this entry
dsp the name of the interface
that should be used for this
entry
Now, when you attempt to connect
to 44.48.70.22, this ARP entry will be
used. So, we're halfway to the solu-
tion—JNOS will now use the correct
hardware address for NIEWO. What
about the digi?
JISIOS also maintains a routing list
for AX. 25 traffic. Using a very similar
technique^ we add the information
about KB9BWE— our digi— to the
AX. £5 table. From the JNOS command
prompt:
ax25 route add niewo dsp kb9bw^
ax25 the JNOS AX.25 command
route the route sub-command
add tells JNOS to add the
fol [owing information to the
AX.25 route table
dsp the name of the interface
to use
kb9bwe the name of the digi (more
than one can be specified)
Now, JNOS knows everything it
needs to about how to reach
44,4S,70,22 from your station. When
you "telnet 44.43.70.22" it finds the
hardware address already in its ARP
table and the AX.25 n^ute table tells it
to use a digi to get there-
More next month. Tit then 73 de
NIEWO.
MF J HF/VHF SWR Analyzer
. . . Read your antenna SWR from 1.8 to 170 MHz . . . built-in 10 digit LCD
frequency counter. . . RF Resistance Meter™. . . smooth vernier tuning . . .
ji
jjuj^^f^^^J^^^
*
^^^^^^^E^^^^l
mmfii^iumitoa-ttp:,
i
J^'i^.^H 'J id
i
AaitAvEHann
"■i
1 1 -
;
L-..J-
1
-•jij' ''' i • i. 1. j'S a i ■ '^-^rit^* "^ ■
i
.,-:.,;-
1
., mKm^'---
1: .
E^:SJ^H
MF^259
Mrj-259 handheld
Univeral SWR Analyzer^
lets you read your antenna
SWR from L 8 to 170 MHz quickly and
easilywithout any other equipment!
MFJ*S exclusive RF Resistance
Metef* lets you mea*5urc RF resistance up
to 500 ohms at mininiuin SWR,
Has built-in 10 digit LCD fequency
counter and smooth vernier tuning.
You get /(?«r instruments in one . . .
10-digit frequency counter , , , RF
signal generator . . . SWR Analyzer^. . ,
RF Resistance Meter"-
Measure antenna resonant
frequencies and 2:1 SWR band widths.
Adjust mobile antennas, antenna tuners
and matching networks in seconds.
MFJ-949E 300 W Tuner
MFJ-949E ^of Id^s most popuTar
*14V antenna tuner covers L8-30
MHz, has lighted peak/
average Cross-Needle SWR/
wattmeter, 4: 1 balun for balanced lines
dLndfutl size 300 watt dummy load.
Versatile 8 position antenna switch
lets you pre-tune MFJ-949E into
dummy load to minimize QRM.
Custom inductor switch was
carefully engineered to withstand
extreme voltages and currents.
Cabinet has tough vinyl coating
and molecular bonding - not paint,
VHF/HF PaclMl INCs
MFJ4270B
^ tf * *
MFja270B super TAPR TNC
clone has a world wide reputation as
the most reliable packet TNC in the
world - many work 24 hours a day for
years without a single failure!
Fully TAPR TNC-2 compatible,
VHFa/niHFoperatiou,/re^ AC power
supply, new enchanced mailbox
expandable to 5 12K with auto/reverse
mail forwarding, WcFAX mode lets
you print weather maps, optional
plug-in 2400/9600 baud modems,
KISS interface, MFJ Host mode.
MFJ TNC/Mk Switah
4FM272B
Switch between your TNC or
microphone by pushing a button!
Just plug pre-wired cables into
your rig's mic connector and TNC,
Plug-in jumpers let you use nearly
any rig with 8 pin mic connector.
Mrj-1272B, S34.95 /MFJ/TAPR TNC2
clones; MFJ-1272BX/PK^232;
MFJ-1272BYy/KAM VHF/KPC3;
MFJ-1272BYH/KAM HF Port;
MFJ-1272BZ/PK-S8, $39-95 each.
For 8 pin RJ45 modular phone jack re-
place B with M in model number above.
ttegeneroHve RCVR fGI
MFJ-8100K
MFJ-8100W .. .. .
*7©**>vi>ed Build ihis regenera-
tive shortwave receiver kit and listen to
shortwave signals from all over the
world with just a 10 foot wire antenna.
Has RF stage, vernier reduction
drive, smooth regeneration, five bands.
MFJ-1278B Miihi-Mode Data Conironer
Use this
MFJ-1278B, your
transceiver and
MFM278B
computer to transmit and receive digital communications! You'll
discover a whole new world of ham radio and communicate in ways
you never knew existed on our ham bands.
The world class MFJ^1278B Multi-Mode and MuUiCom'^
software is packed with features no <9^fter multi-mode gives you.
You get 10 digital modes . . . Packet, AMTOR, FACTOR (at no
extra cost), RTTY, ASCn, Navtex, Color SSTV, 16 Gray Level FAX,
CW and Memory Keyer plus an enchanced 32K Mailbox,
Youll have fun joining worldwide packet networks and exchanging
color SSTV pictures widi your buddies around the world. You'll marvel
at/w/f color FAX news photos as they come to life on your screen.
Youll see weather changes on higby detailed weather nmps in all 16
gray levels. You'll eavesdrop on late breaking news as it happens on
RTTY. You'll enjoy error free HF QSOs on FACTOR and AMTOR and
receiving packet mail in an enchanced 32K mailbox. Want to copy
some CW? Just watch your screen.
MFJ- 1289, $59,95, MultiCom^" software and cables.
MFJ haHwave vefficnf Anteima
6 bands: 40, 20, IS, 10^ 6, 2 Meters ...No mdiab or p^und needed!
Operate 6 bands - 40, 20, 15, 10, 6 mfj-1796
and 2 Meters -with this MFJ-1 796 ii om*
ground ir^dependent halfwave ve rtical * ^^
antennal No radials or ground ever neededl
It's only 12 feet high and has a tiny2A inch
footprint! You can mount it anywhere from ground
level to the top of a lower - on apartments, condos,
small lots, even on motorhomes. Perfect for
vacations, field day, DX- pedition, camping.
Frequency selection is fully automatic - all you do is
transmit. Its low angle ofradiatior} really reaches otit andj
brings in DX. Omni-diredionaL 1 500 watis PER
Efficient end loading, no lossy traps. Entire length,
is always radiating* Full size halmave on 2 and 6
Meters. High power air-wound choke balun
eliminates feedline radiation. Adjusting one band has
minimum effect on other bands. Add $20 s/h.
Easy to assemble - you'll have ft on the air in an afternoon.
Measure RF resistance^ inductance,
capacitance, resonant frequency of tuned
circuits, transmission line velocity factor/
impedance/ loss. Test RF chokes, baluns.
MFJ-209, $109.95, same as MFJ-
259 less frequency counter and RF
Resistance Meter™.
See free MFJ catalog for complete
line of MFJ SWR Analyzers^,
Super IftQ Loop Antenna
MFJ- 1 786
lirty 36 inch
diameter bigh
efficiency loop
antenna covers 10*30
MHz continuously y,.-
with low SWR. Handles 150 watts.
Ideal for home installations where
space is limited- apartments, condos,
small lots. TUke on trips.
All welded construction.
Remote control has Automatic
Band Selection''', Cross-Needle SWR/
Wattmeter. No control cable needed.
Use batteries or 1 10 VAC. Add$20 s/h.
No ground or tuner needed.
MFJ- 1782, $269.95, like MFJ-
1786 but remote control has only
slow/fast tune buttons.
Oyal Band Mobile Ant*
Mobile Antenna for 144/440 MHz
hand magnet »i^m f
mount mobile **
antenna for 144/440 MHz
has 19 inch stainless steel
radiator, low SWR. For
mobile rigs with SO-239
UHF connector and handie-talkies
with included BNC adapter.
5/8 Wave Mobile Ant.
Maximum .jf^.. .^^r.
Gatn 5/S *24*»
MFJ's W0M Aimovs 3 iCW Veisa Tuner V
Here's why the MFJ- MFJ-989C
989C is the fmest 3 KW *34*"
antenna tuner money can buy . . .
Two massive 250 pf
transmitting variable capacitors can
handle amps of RF current and
6000 RF volts. Logging scales. ^ _
Precision ball bearing roller inductor, three digit turns counter and
spinner knob give you exact inductance control for minimum SWR.
Lighted p^^s^/average Cross-NeedLe S WR/Wattmeter has 200/2000
watt ranges- Super heavy duty current balun has two giant 2V2inch
powder iron toroid cores wound with Teflon® wire.
Six position ceramic antenna switch has extra large contacts. Flip
stand, dummy load, one year unconditional guarantee, aluminum cab-
inet, tough baked-on paint, locking compound on nuts/bolts, handles
3 KW PEP, 10V8x4'/2xl5 in. Meter lamp needs 12 volts. Add $13 s/h.
Wave 2 Meter
magnet mount mobile anten-
na has stain iess steel radia-
tor, 12 ft coax, low SWR.
UHF mobile (MFJ- 1728) or
BNC handie-talkie
(MFJ-1 728B) connector.
5/8 Wove Ground Plane
$19.95 gets MFJ-1750
you a 2 Meter 5/8 *X»«
wave ground
plane home station
antenna! You get the
highest gain of any single
element antenna, shunt fed
matching, ceramic
insulators. MFJ-1752,
$19,95, for 220 MHz.
finee MFJ Catalog
Write or c(m. . . 800^7-1800
PPPW"
*ffw?ffr^
1^
MFJ*s famous one yeariVo Matter What"" unconditional
gtmrantec means we will repair or replace (at our option) your
MFJ product sold in this ad no matter what for a full year. •
Nearest Dealer/Orders: 800-647-1800
Technical Help: 800-647-TECH (8324)
• 1 y^r unconditimal guaraatee ' 30cfay money back
guarantee (less s^h) on orders from MFJ ' Free catalog
MFJ EISTTERPiaSES, INC,
Box 494, Miss. Stale. MS 39762
(601 ) 323-5869^ 8^:30 CSX Mon-M
FAX: (601)323-6551; Add $6 s/h
MFJ. . - making quality affordable
P?ice& and speeificatioiu! sutijcci to chinge © 1 9*^ MFJ Enlerpns
,biE.
CIRCLE &6 ON READER SERVICE CARD
Homing in
1 8 on your Feedback card
JobMobURE. K0OV
RO. Box S50a
Fuf tenon CA 92633
Attenuators Made Easy
Carelylly planned deception can
make the difference between a simpte
hidden transmitter hunt and a real
challenge. JusI as a football team re-
lies on deceplion to loll the opponent's
defense, hiders in radio direcrion find-
ing (RDF) coniests (called foxhonis or
T-hynIs) do Itieir best to cause hunters
to make incon^ect assumptions about
direction arxf distance to their location
Last April's Fullerton Radio Club
mobile hunl is a good e)(amp1e.
WA60PS and I helped WB6GCT and
WB6UZZ hide it. At the starting point,
our signal was from the north and was
quite weak, S-meler readings were
about the same with the hunters* yagis
and quads set to either horizontal or
vertical polarization.
Figuring that the T was near the
distant bour>daries. some learns boil-
ed br the freeway to head north. Gib-
ers, suspecting that we were mffectmg
our signal from the front range of the
mountains 25 miles away, headed
east or west on a hunch. All IS teams
lost the stgr^al upon leaving the start-
ing hil[, but they kept going,
AJi had tseen deceived. Our T was
only three miles north oJ the Start, on
the side of a hill thai blocked the sig-
nal toward the freeway. A paltry 2.5
microwatts drove an 11 -element beam
pointed toward me start. It was two
hours fater that the first team found
ttie transmute f. The six teams that
managed to find it that nighl had driv-
en from 22 to 52 miles. They were
fooied by the careful ly-contro tied pow-
er level and antenna position.
Our fox transmitter put out such a
Radio Direction Finding
meager signal that a hunter could
drive from Ihe start point to within 100
feel of its antenna without the S-meter
ever registering full scaie. That's very
unusual, since the 5 to 50 watt hidden
transmitters encountered on most mo-
bile hunts usually pin hunters' signal
irxjicators when they are several miles
away. Typical VHF*FM receiver S -me-
ters have only a 20 to 30 dB range.
Antidotes for Overload
Every T-hunter who gets bearings
with a directional antenna and S-meter
requires some method for knocking
down strong signals to Ihe point tfiat
amplitude char>ges can be discemed.
But RF gain controls are pmvided in
only a few VHF transceivers, usually
the relatively expensive mulltmocfe
models. If you are thinking of purchase
ing such a rig just to have RF gain
control for T-hunting, be sure to test it
before you buy. In many cas€S, lower-
ir^g the RF gain control adversely af-
fects S-meter action. You may not be
able to take bearings with gain re-
duced.
If you enjoy performing minor elec-
tronic surgery inside receivers, you
can add internal RF gain reduction
that won't upset S-meter action. Con-
trol the supply voltage lo the RF
preamp and first mister stages, or
change the tBas o( tfre FETs in these
stages. The "Homing In' column in the
March 1989 issue of 73 Amateur Ra-
dio Today provides plans for a voltage-
reduction internal attenuation system
for popuJar VHF-Ff^ transceivers.
A simpler and much more popular
way to knock strong signals down
lo size is to connect an attenuator
bO)c between your antenna and recetv-
er input. A resistive (sometimes called
a "passive") attenuator has several
shielded sections, each with resistors
Photo A. You can buifd your own resistivB alienuaior from PC l)03fd mat&riai,
switches, and resisiors^ Or you can buy a finished unit iike this from Arrow Anten-
na, its copper-ciad case measures 2" x 4^3/4" x 1-1/4\
Ptioio B, inside view of the Arrow resistive ailenuaior showing tfre five shielded
ceifs and two hinges made from copper btaid.
to soak up the RF signal and a dou-
ble-pole double-throw switch to put
the section into and out of the line
(Photo A).
With the circuit in Figure 1, you can
sel ad signal reduction in 5 dB steps
from zero to 75 dB. RF leakage across
the switch makes attenuation of more
than 20 dB per section impractical If
your receiver is especially
well-shielded, you can
add another 20 dB section
to get 95 dB maximum.
More than four 2D dB sec-
tions are not worth the ef-
fort, due to tt^ likelihood
of f^F coupling around the
attenuator and leakage
through the receiver case.
This attenuator is an easy and inex-
pensive construction project. Build the
multi-cell enclosure out of doubie-skl-
ed unetched PC board material or
sheet copper Solder ttie dividers aixl
end caps in place with a continuous
bead of solder before mounting the re-
sistors, connectors ^ and switches.
Figure 1. Schematic diagram of a simpie five-section resistive attenuator for T-hunting on any ham band from
160 meters through 70 centimeters, l^esistor vaiues are /n ohms. Switches are shown in down (attehuation out)
position.
60 73 Amafeur Radio Today* July, 1994
Photo C, The Arrow Antenna offset attenuator is in
a 2-3/3" X 3-3/4' X Vptasticbox.
From RDF
Antenna
Out
Mixer
+V
To Receiver
Attenualion
Control
1
1 MHz
Osc.
Figure 2. Bfock tHagmm of the external offset attenuator.
Do not secure the back cover with
a long solder bead, because that will
make it d iff feu It to open for repairs. In-
stead, make hinges out of braid mate-
rial arMJ install ttiam as shown tn Ptxjto
B, Bott the cover closed or fasten it
with copper tape. The hinges hold ttie
cover arxl preven! unwanted leakage
and coupling. A hinge in each cell \s
ttest
The resistor values shown in Figure
1 ensure that the receiver and anten-
na remain terminated with the same
impedance as the SO-ohm coax line at
all attenuation levels. Use only ca^tKin
composition or caition film resistors
*or RF attenuators — never wi rewound
or metal film types.
Quarter- wall res[stof& are OK, but I
prefer half -watt parts. They withstand
accidental transmissions for longer pe-
riods. It's even better to use 1 or 2
watt resistors, but installing them in
the cramped ceEl space is very ditficull.
Keep all resistor leads and jumper
wires as stiort as possible. Jumpers
between ceHs are straight rnsuiated
wires passing through small holes in
the dividers.
Good quality slide switches give
belter BF performa,nce at VHP Ihan
toggfe switches, but they require a
rectangular hole and are less liquid-
proof than toggle swttches* which I
use. Subminiature or micro*mini size
toggle switches tit and work better
than miniature types, but they are
more fragile. In 18 years of T-hunting
use. I have never accidenialEy burned
oul any of the ha If* watt resistors in my
home-brew attenuator, but f have re*
placed several subminiature toggle
switches that wore out or were dam-
aged.
BuHd or Buy?
Commercial resistive attenuators
are available, but nr^ost are expensive
precision units for laboratory measure-
ments. Many do not tisve enough 20
dB sections for T-hunting. Neverthe-
iess, it is a good idea to watch al swap
meets and surplus outlets for suitabre
ones at bargain prices.
T-hunting enthusiast Ailen Lowe
N0IMW now sells attenuators as part
of his Arrow Antenna line of productS-
His resistive mode! has the same con-
figuration as shown in Figure 1. The
case is made from Rberglas PC board
materia], tt uses slide switches with
gold contacts and quarter- watt resis-
tors. Bolts arKl wing nuts hold the rear
cover, so it is easy to open for repair.
You can choose either UHF (80-239)
or BNC connectors when you order.
1 tested the unit in Photo A on the 2
meter band with a well-calibrated sig-
nal generator Perforrrrarrce was typi-
cal of T-hunt attenuators. Insertion
loss wiih no atlenuation was 2 dB.
Each step had accuracy ol 1 dB or
better. Maximum attenuation with all
sections switched in was 71 .5 dB.
To Sotve Leakage, QSY
Handie-talkies and scanners are
notorious for poor case shielding. A
passive attenuator cuts down the sig-
nal level tnio the antenna jack, but
strong signals wilt still penetrate the
case and pin the S^meter. One way to
gel bearings on nearby foxes with
these sets is to convert the strong on-
frequency signal into a weaker off -fre-
quency signal. Then you can tune
your receiver to the offset signal and
fT^asitre its strength versus direction.
Figure 2 is the block diagram of a
simple unil for level-controlled fre-
quency conversion. When this scheme
was ohginaEly descnbed in OST maga-
zine. Novemt>er 1992, by Anjo Een-
hoom PA0ZR. it was called an active
attenuator. Since there are other kinds
of attenuators that are also called "ac-
tive,^ I prefer to call tt an offset attenu*
ator That temi describes how it solves
case lealcage by offsetting the fre-
quency.
An offset attenuator consists of a
local oscillator (LO) connected to a
diode mixer through the attenuation
control. The higher the LO ieveL the
higher the amplitude of the offset sig-
nal applied to the receiver. To Increase
atlenuation, decrease the LO signal
Into the mixer with the control.
Arrow Antenna*s new
attenuator line includes
an improved version of
the PAOZR design {Pho-
to C). Instead of a 500
kHz L-C oscillator, the
Arrow unit features a 1
MHz SaRonIx crystal
clock rnoduie, which has
higher accuracy and sta-
bilily 1 MHz is a good
choice for the frequency
offset, because it is easy
to remember and pro-
gram into your radio.
The trade-off tor im-
proved stability is higher
supply current, appfoxi-
mately 35 mjlliamperes.
A three-terminal regula-
tor provides 5 volts to
the LO, so performance
IS stable with battery
voltage down to 6.7
volts. A 9-volt alkaline
batlery should power the
unit for at least 12 hours. Arrow does
not provide a power-on or battery con-
dition indicator, but there is room to
add them if you wish.
The unit I tested was one of the first
made by Arrow, and did not include an
instruction sheet. No problem^it is
very easy to use. Using Bf^C jumper
cables, hook it between your direction*
al antenna and receiver The connec-
tors are not labeled. With the simpie
1N4148 diode mixer In the Arrow unit,
it does not matter which port goes to
the antenna and which to Vh^ receiver.
In my tests on 2 meters, insertion
loss of the swilched-off unit was 0.Z
dB. On-frequency attenuation with
power on ranged from 7 to 17.5 dB
with adjustment of the attenuation
control. Tuning the receiver up 1 UHz
gave attenuation of 11.5 to 101 dB
over the control range.
The LO module puts out a TTL
square wave, its harmonics, especially
odd multiples, are very strong. You
can tune up or down in 1 MHz steps
and hear the target signal at varying
attenuation levels. Untortunaleiy ttiis
means that the chance of interference
from cross-modulation products Is
much greater than if the oscillator
put out a pure sine wave. For exam-
ple, if you are hunting a T on 147.48
MHz, you will get interference from
strong pagirtg transmitters on 152.48
MHz,
Figure 3, which charts my mea-
surements of minimum attenualion at
the 10 closest offset frequencies, can
help you predict the level of cross-
modulation interference and select the
best offset frequency to use. Generally
speaking, cross-mod is less severe
when your offset is an odd multiple
away From the desired signal and an
even mult^e away from the undesired
Signal, tn the example above, the pag-
ing transmitter will cause stn>ng QRM
to the 149.43 and 151.48 offset signal,
but much less Interference to 148.48
and 150.48.
Amow literature says that tiie unit Is
60 T
50 -
DD
40 -
« 30 -
<
E
E
20 -
10
0
$
o
O
N
N
1— ojrr>^i-ncDN.00ff>O
Figure 3. The Arrow of^^ attenuator's square wave iocal oscitiator produces a
multitude of hQferodyne signals at 1 MHz intervais with different levets. This chart
shows the retative amplitudes at the receiver, with respect to the input signal tev-
ei. Attenuation control is set to tninimum.
73 Amateur Radio Today • July, 1 994 61
AMATEUR TELEVISION
GETTHEATviuG^^^
NekylOWatt
OOl#/ Q
• ••
Transceiver
Only $499
«>o
Made in USA
Value + Quality
from over 25yearB
In ATV...W60RG
Snow free line of sight DX is 90 miles - assuming
14 dBd antennas at both ends. 1 0 Watts in this one
box may be all you need lor local simplex or repeater
ATV. Use any home TV camera or canrxxirder by
plugging the composite video and audio into the front
phono jacks. Add 70cm antenna, coax, 1 3.8 Vdc @
3 Amps, TV set and you're on the air - it*s that easy!
TC70-10 has adjustable >10 Watt p.e.p. with one xtal on
439.25, 434.0 or 426.25 MHz & properly matches RF
Concepts 4-110 or Mirage D1010N-ATV for 100 Watts.
Hot GaAsfet downconverter vartcap tunes whole 420-450
MHz band to your TV ch3, 7.5x7.5x2.7'* aluminum box.
TrartsmJttsrs sold only to licensed amateurs, for legal purposes,
verified in the latest Callbook or send copy of new license.
Call or write now for our complete ATV catalog
including downconverters, transmitlers. linear amps,
and antennas for the 400, 900 & 1200 MHz bands.
(81 8) 447-4565 mi Um-s.^upm fwt.
P.C. ELECTRONICS
2S22 Paxson L»no Arc«di« CA 91007
Vim, MC, COD
Tom (WSORQ)
liarymn (WBSYSS)
mumiOHS n maks mio mi
NEW.
J994'95
IMGLUim
FOfiEVGPnr
cwmwn
"♦aFi>
HAXIS
jlfrTERE
Qstrs
MORM
IfrTERESTIMC!
Our new WOaOWlDE RADIO
ATLAS wBI help moke your
QSO's more fun on6
intefesting. When you talk to
an overseos horn you will
know more obout his
countiy. IfKiludes rcxJlo and
geogfcphical iriformatiori for
over 320 countries. More
than 325 pages! - _ _
S^ $19.95
MOW INCLUDES
AUTOMTC^I
TOM ESI
INCLUDES;
10M. 2M
220HltE
900 HHx
1.2 aHz
Our quoffty l^epeoter Mops arm now
ovoilobte in book form! TTKirs right,
our new book inckide^ ou U,S.
Stote*. oil Conodkan Provincds,
Mexkio. Central Ameik^ and the
Conibbean! Mop* show city
Eocofion, lepeotefs, highway*, hom
decders. and touiBt informalkxil
PERFECT FOB TRAVEL! Mof# than 1 75
ORDER TODAY! $9,95
m» meiomt nmATsn map mnoEs
A whole now way to
enjoy our map cardi!
The regionol guide
Includes lix laminated
itcite corcfe. spiral bound
for eosy use. Very
handy.
Hh AK, WA, OR, \D/Mf.m
#2' AZ, CA, HI, NM, NV, IX
#3- CO. m, KD. SD, UT, WV
#4- lA, KS, MN, MO, NE, OK
f5- AU AR, LA. MS, MO. Ol£
#6- Als GA, a, lA, MS, Til
and supef for #7-Ky,MD, NC. sc, \*k.wv
vipu, travel!* ^_ iii-a,JN. ky^mi. oh.wi
HUSS3.00SmCO OR i*- Ot h«>. NJ, NY, OH, f*
LOftAAMINAJtDV * * '^^ f ifu CT. mf. MA. HM. B. VT
FBenterpiises
23801 NWlsf Ave.
Rrdgefietd, WA 98642-8830
CALL TODAY! 1(800)377-2339
Qeoi&- inquiries Wefcome
MSP&aSKiMPS
Repeater maps for
every state, plus
Conoda. Maps ore
f^ll cotor, and
ianrdrxsted In pkistvc.
Stx>ws 2m, 220. 440.
900: cmd 1.2 GHi.
Newty Updated!
CATALOG $2
BfFUNDED WITH RtRCHASE
INDIYlDilAL MAPS
ADO 50* SHIPPING
BOOKOTOERS
ADD $3.DD SHIPPING
not suitable for hynling a fox on an ex-
act 1 MHz multiple (such as 147.000
MHz), due lo ORM from harmonics ot
the oscillator The harmonics are
strongest ai minimum attenuation set-
ting. They wert lull scale on 2 meters
'm my fTx>blie seiup. and half to ttiree-
quarter scale on ttie 222 and 440 MHz
barxis. However, with extra care in ad-
justing the attenuation control. I was
stil! able to get bearings on a strong
test signal on 147.000 MH2. LO har-
monies are a problem when an even*
megahertz fox signal is just strong
enough to pin the S-meter. but they
will not cause trouble when you get
very close 1o the T and raise ttie atten-
uation control settir^g.
There is no isolation between the
mixing diOde and your antenna. Offset
signals not only go inlo your receiver,
tkit they also go back to your RDF an-
tenna, wtiere they are radiated. This
may cause Cfoss^modutation ORM to
neart>y receivers, even outside the
ham bands.
The Bottom Line
An oflset attenuator is excellent for
on-foot foxhunting^ whether you use it
for "sniffing" at the end of a mobile
hunt or for European/Asian style in-
ihe*woods radiosports. It works with
directional antennas or Just with a rub-
ber duckie as an aid to the "body
shield" maneuver.
On the other hand, a resistive at-
tenuator Is a better choice for mot)ile
RDF, in most cases^ Passive attenua-
tors avokJ the problems of images and
re- radiation that are far more harmlul
in mobile situations than on fooL
Usually, the only time an offset at-
tenuator is superior to a resistive al-
lenualor in a mobile setup is when you
are ctose to a powerful hidden T and
your mobile rig is overioaded with all
resistive attenuation steps in. In such
a case, connect tt\e offset attenuator
tietween the resistive attenuator and
the mobile fig. To minimize re- radia-
tion ORM from your mobile RDF an-
tenna, set the resistive attenuator to
20 dB or more.
Remember that an offset attenuator
does not significantly reduce the level
of on-frequency slgna! Into your radio,
so It does not provide protection tor
your receiver's front end. If you touch
your RDF antenna 1o the antenna of a
powerful fox transmitter, you may
damage both the receiver and the off-
set attenuator.
Avoid transmitting through any ex-
ternal attenuator. You may damage
tt^ resistois in a passive unit. You will
transmit strong spurious signals if you
key up through the olfset attenuator,
and you may bum out ils diode. Dis^
connect the mike if you are T-hunting
with a mobile ng. Set the power output
down to the lowest possible level on
your hand-held, Fortunatelv, if you for-
get and cause a failure, repairs are
easy and inexpensive.
Mali-order price of the Arrow offset
attenuator is S59. The resistive attenu-
ator sells for $49, For more informa-
tion on Arrow products, txintacl Arrow
Antenna. 1461 Peacock Place, Love-
land. CO 80537: (303) 663-5485, To
contact me. wrile to my California
address under the headir^. Remem-
ber that a self-addressed stamped
envelope for the reply is always appre-
ciated.
Sell your product in 73 Amateur Radio Today!
Call Dan Harper at 1-800-274-7373. |
Ham help
Number 19 on your Feedback C3fd
CVRCLE 33 ON FIEADEH SERVICE CARO
62 73 Amateur Radio Today • July, 1 994
We am happy to provide Ham Weijp iistirygs free on a space avaiiable basis. To
n^ake our job easier and to ensure ttiat your Hsting is correct please type or print
your request deariy. douGfe ^aced, on a full (8 ^fT x ti'} sheet of paper. You
may also upload a tisting as E-maif to Sysop to the 73 BBS/Sp&ciaf Bver}ts Mes-
sage Area ^I't. (2400 baud & data tits, no parity, t slop bii (603} 924'9343}.
Pfease indtcafe if it is for pubitcatfon. Use upper- and lower-case fetters where
appropriate. Also, print numbers carefully— a f, for example, can ije misread as
the letters f or i, or even the number 7. Specifically mention that your message is
for the Ham Help Column. Phase remember to ackriowiedge responses to your
requests. Thank you for your cooperation.
I have recently "inherited" a
RADIO SHACK TRS-80 Model III
with no software, operating sys-
tem or docurnentation. My local
Radio Shack has been unable
to heip nne. Since I am planning
on dedicating the machine to
packet. I knew ( would be bet-
ter off relying on my fellow Ama-
teurs. I will gladly reimburse you
for your expenses. Thank you,
Johnny E Brown NiQQS. RO,
Box 1305-226, Brunswicfi ME
04011.
I need the schematic for HEATH
Company Model SA-5010 Keyer,
Your help will be greatly appreciat-
ed. Tom Stepanov RA6AR/WN1R,
P.O. Box 555, Sochi'355, Russia
354355^
WANTED: Manual (for a>py) for
ICOM IC*245 2 meter transceiver. I
only need the sideband adapter in-
formation, or any computer inter-
facing information, Oaude J. Cook
KD6NFJ, 34 A Springbrook Rd.,
Westerly Rl 02891.
Atv
Number 20 on your Feedback card
Ham Television
W4HTB Repeater
Hank Cantell W4HTB of Bowling
Green, Kentucky, decided \o slir up
some ATV activlly in the r^gbn with
an ATV repeater. Me obtained permis-
sion from the k)cal TV station (chan-
nel 40) to locate the repeater at their
transmitter sire about 15 miles north
of town (700 feel above aveiage ter-
rain). With his antenna at the ISO-toot
level, Hank's repealer provides great
coverage ttiat indudes Glasgow, Ken-
tucky {about 30 miles to the north*
east).
Features
The repealer fias both in-t>and and
cfossband capabilities. The input is on
439.25 MHz with outpuls on both
426.25 MHl AM TV as well as 1280
MHz FM TV {5,8 MHz audio).
One of the most unusual futures
of the repeater is the ability to transmit
two differenl audio channels through
Ihe use of bolti subcarner and on-car-
rier sound on the 426.25 MHz output.
The subcarrier audio channel relays
Ihe rwrmal ATV audio signal while Ifie
on-carrier channel listens to the
t44.34 MHz FM receiver that's locat-
ed at the repeater site. Not only does
the system work as an ATV repealer
but as a crossband FM voice repealer
as weiii
Touchtone control via the VHF re-
ceiver allows the users to turn the
426.25 MHz outpul Oft SO that Ihe sys-
tem works solely as a crossband TV
repeater to allow link capabiliry with
dher repeaters. Hank plans to install
an additional receiver on 42t^S MHa
10 allow his repeater to relay \he out-
put of the KJ4ZO ATV repeater In
Nashville. Tennessee (50 miles to the
soulhK
Another Touchtone command al-
tows the user to turn on Ihe repeater
continuously for DX contacts (essen-
tially links the receiver directly to the
tnar^mitter without the need for sync
trigger}.
Additional commands wHI turn on
the video ID, switch in another video
source or a five shack or tower cam-
era.
The Hardware
The repeater is horizomtally polar*
ized on the 70 cm band. A stacked set
of "Quad Uttle Wheels' by Oide An-
tenna Labs is mounted at the 160-toot
level of the tower, feeding a 20Q-foot
run of t ■ hardline to the equipment
room. The signal is split to the receiv-
Phok> 8. Tbe component parts of itie W4HTB repe^t&r are asseaitiBd in Hank's
finai test ^diity.
er arvd the transmitter using a TX-flX
#2S-6S^l A duple Ker«
The receive system consists of a
PC. Electronics ATVR-4 receiver that
deiiveis video to the video switch and
sync detector circuit. The video ID
and alternate video sources can be
routed through the video switch as
well (controlled by Touchtone com*
mands via Ihe VHF receiver). In addi-
tion, the 426.25 MHz transmitter can
be controlled by Touchtones. The
video signal from the switcher goes to
both Ihe 426.25 MHz AM-TV transmit-
ter and the 1280 MHz FM*TV trans-
mitter. The 426 25 exciter was made
by Best link and feeds into a Pauldon
18-watt amplifier (PD-440N) and
routes back into the duplej^er The
1280 MHz FM'TV transnRitler is a
Wyman Research system that in-
cludes an exciter Into an SC1043 am-
plifier brick. The 1280 MHz antenna is
a 9 dB gain Diamond vertical.
Activity
If you're In the Bowling Green area,
try giving the local ATVers a call on
144.34 MHz. They usually are active
every evening atler about 3:30 p.m. If
you're operating mobile TV, the re-
peater is located right next to 1-65
{ne&f exit 39), Some of the more ac-
tive ATVers in the region are Hank
W4HTB. Dean K4NQV. Fred
KA4CFW, Ben W04MNI. Bob
KB4FEN, Randy KD4AMfl, and Paul
K4VXP (located 60 miles away In
Gampbellsville).
Night-Vision R/C
During a fecent visit to the W4HTB
QTH, Hank treated me with a demon-
stration of his night-vision ATV rover
He mounted an ATV Iransmitter and
an Infrared sertsttive CCD camera on
a USA'1 Monster Tmck R/C car. This
vehicle is capable of traversing in*
credibly difficult ten'ain due to its four
monster balloon tires. The camera is
offered by Marshall Electronics and
has six high-intensity infrared LEDs
mounted around the lens, allowing the
camera to see about 15 leet in total
darkness. Hank has great fun driving
the vehicle around under the house
as well as venturing out in the woods
at night looking for nocturnal crea-
tures. A vehicle lil^e this has a number
of interesting applications including
potential use as hazardous emergen-
cy support.
Photo A. Hank Cantreil W4HTB working fns A* r repeater from his ham shack in
Bowling Green, Kentucky,
ffholo C, The W4HTB night-vi^)n R/C vehtcie.
73 Amateur Radio Today • July, 1 994 63
Nurntwr 21 on your Fe^tiack card
^m nurnwr zt on your re
Above & beyond
VHF and Above Operation
C. L Hmghlon WBStGP
San Diego Microwave Group
G345 Badger Lake A\^,
San Diego C A 92119
Frequency
Last month we discussed convert-
ing a phase -locked synthesizer/oscilla-
tor for 2. XXX GHz. This month I wilJ
butid on last month's project and de-
scribe In detail the multiplier the filter,
and the oscillator drive amplifier.
These componenis serve as an osdl-
rator mullEplier. which ccu^ be used in
conjunction wfth a 10 GHz converter.
The attempt here is to utilize inexpen-
sive surplus components and PC
boards to ftii a need, ar>d to constaict
a converter package ttiat is smalt and
funcljonal. and doesn't cost an arm
and a leg lo diipllcate.
Faliing back for just a minute, I
would like lo touch base on the syn-
thesizer, in particular on the power
supply you construct to power these
PC boards. These devices require a
vary dean DC power supply. By that I
mean that the ripple content has to be
quite pure or else you will have modu-
lation on your oscillator caused by t^e
AC r^apie component ndmg on the DC
in your power supply. It does not lake
much lo cause noise or FM moduia-
tion on the synthesizer. To make sure
this doesn't happen to you* filter your
DC supply well
Pete Bauer W6DXJ, who has done
quite a tew of the conversion details
on the synthesizer unit, recommends
using a good voltage regulaiof to
maintain DC regulation. AddilJonalty
using some ferrite beads on the DC
distribution leads at the oscillator to
suppress AC and other RF will prove
useful I usuaFiy bypass the output of
my voltage regulators with not just a
suitable electrolytic cap. but with a
couple ol extra bypass types (0.1 \if
and 0.001 pF) as well, to cover all
bases on the positive lead. See Figure
1 for the schematic detail oi power
supply configu ration.
The PC boards that I am modifying
here ware part of a microwave trans-
mitter/receiver used on trucks for com-
munication and data, As such, they
were built quite ruggedly and, need-
less to say, are solid-state, with GaAs-
FETs in almost all of the circuitry. This
month ril describe the second portion
of the oscillator system, namely the
osciHator multiplier Please note that
this is but one of many methods used
to obtain a 10 GHz injection for 10
Ftgufe I. Power supply teed details. Basic vottage regviator power supply: oufpiit
capacitors vary in value 70-0. 7-0,007 iiFfor wtde-rarrge bypass Mering.
Photo A. The original multiplier PC board— 2.620 GHz In, IJ, 1 GHz output This
uses fwo Mitsubishi GaMFETs, MGF'13i^.
GHz operalion. The PC boards that
are described here are bemg made
available; you ran order them for S10
per boaro ppd Irom the author.
A tsrief descriplion of these PC
boards: As stock they were made to
operate at 2.620 GHz (synthesizer),
and the multiplier was a times-five.
providing 13.1 GHz output from the
set of PC boards, fii^ultiplication was
done in the first stage of the second
board in an MGF-1302 GaAsF^ de-
vice. The output of this stage was cou-
pled into a siripline filter resonant at
13.1 GHz to allow bandpass operaikjn
of the desired 51 h harmonic and re-
duce alE other kequervcies. The filter
output is coupled with a small-value
capacitor lo an output ainplifier tuned
to 13.1 GHz, another MGF'1302
GaAsFET device,
In the original system, the amplifier
of the multiplier assembly was fed to a
distribution ampHfier system on a third
PC board. This board contained an in-
put amplifier and power splitter. A
power splitter is a strip line device that
looks tike a tuning fork with the lop ter-
minated In a resistance load. Its pur-
pose 1$ to split the signal (one source)
into two equal sources: one source for
Out To
TransmiL
RF IN
13.1 GHz
Out To
Receive
hliKer
S
Figure 2. Microwave spfliler amplifier PC board diagram, Note the local oscillator mixer drive ampiifiers. this PC mard uses
four MGF'1302 FBTs. The dual-st^ge amp has been cut from the main board and readjusted to 10 GHz.
receive and the other for transmit. Tvro
additional amplifiers are located in the
Iransmrt path, and there ts one in the
receiver path. These amplifiers have
been removed from this PC board by
cutting the board and making two tO
GHz amplifiers, a two-stage and a sin-
gle-stage unit. This board is not re-
quired in the multiplier modification,
but can be used by removing the sin-
gle- and dual-stage amplifiers and
converting Into Individual amplifiers.
These amps can be used at 10 GHz
as gain bk>cks with siripline srx>wf1ake
retuning from 13.1 GHz. See Rgure 2,
the sp fitter tx>ard btock diagram.
The multiplier PC board is of prime
concern now, along with our attempt to
modify it to a frequency multiplication
of four, fn tt^is regard we need to modi-
fy the output circuit of the fiis! stage
from 13.1 GHz to 10.2 GHz. The
siripline filler was tco difficult to at*
tempt retuning lo 10 GHz A better
method is to eliminate the siripline fii*
ter by removing the copper foil with an
X-Acto knife. Our plan here is to re-
place the filter with another type of fil-
ter that can be easily constructed and
assembled — someihing easier than
the original stiipHrte filter. The answer
to this problem is an adjustable cavity
resonator tuned to our 4th harmonic.
Where do you find Such a filter? In
the plumbing section of your hardware
store. Whiai we used is a 1/2" copper
pipe cap plug. Sounds ciazy. yes, but
it worics perfectly and is easy to adjust.
Credit for this filter construction goes
to the North Texas Microwave Society
for passing on the information on the
filter construction.
The copper pipe cap works quite
well, being simple to construct and ad-
just. A finished filter will have about 1
to 1.5 dG loss and a bandwidth of
about 50 to 100 MHz. I haven't mea-
sured Ihe "0' of the friter but believe it
10 be atx>ut IDO, Essentially, the pipe
cap fitter is a resoriani cavity with two
probes, input and output.
These probes are copper or brass
pins about 0.030" In diameter and
3/1 6th' long, The pins are inserted
from the trace side of the PC board
through to the foil side and are aboirl
3/16" high on the foil side. They are
64 73 Amateur Radio Today My, WB4
-Jli.S^
Ptioto C, The top of me PC board enclosure for the maWpfier, snowing the ppe
cap fitter arxf acf justing scmw poking through the ltd of the PC hoard case. Coax
connectors for input output and DC feed-through capaaiors have been add&d^
Photo B. The modified PC iXMfd, conver^ng the muftiplier to a times 4. Note the
ink dfcie mark and the PC strips removed from the fitter area, located Just aixfve
tfie circle cut-out.
soldered to the mmamtng erxJs of the
oEd fitter strlpline positioned about
1/16' from the inside wall lor the pipe
cap when it is soIderecJ to the Jo i I side
Note the circle drawn for the pipe cap
positioning on the fotf side. The
stripline that remains from the original
slfipline fnter is rraw nothing more tlian
50 ohm stripline which feeds the two
probes of the pipe cap fitter. You will
have to patch the PC board with a few
small scraps of copper foil or solder
bridge ttie traces to extend the new 50
ohm stripline to filter probes. See Fig-
ure 3 for fitter cor^truction details. Ex*
act compliance is not necessary
I started the modification on the
multiplier board t?y removing the filter
traces on the PC board with an X-Aclo
knife. See Photo A. Ihe original un-
modified PC board, and Photo B, the
modified PC board. As you can see in
Photo B, ( drew a circte representir>g
where the pipe cap will be soldered on
the opposite side of the PC board, and
left copper traces on the stripline side
to solder to the probes.
The bottom of the PC board
(ground side), where the filler probes
are to be, Is reamed away to give
clearance for tf>e brass pjns- This pre-
vents possible gn^nding of (tie pins.
To ertsure this and to give them a rigid
structure, I used a partian of Teflon
from 3 scr^p SMA microwave connec-
tor to stip over the pins for positioning
and insuialJor). If you don't fiave a corv
nector to scrap , use the pin from a
DB-9 Of 06-25 connector, as Ihe di-
ameter is just right, and insulate. II you
have a Tefion insufator or tubing, slide
it over the pin to make the pin rigid
and hold the pin vertical arid not
grounded.
ID-8 Automatic Morse Station identifier
Compatlbfe with Commefclal. Public Safety, and Amateur Radio
applications. Uses Include Repeater identifiers. Base Station Identrfiers,
Beacons, CW Memory Keyers, etc, Great for RGC. ID Compliance.
• Miniature In &lze. ^M''^^^^)n\}.!l^y,
• total ly RF immune
■ All connections matfe w\]h mitrodiinlgture plug affd sccfeet wifti ralor ccided wi?issaltaciied
• CMOSrnicraproces-soi tor \m voltage, lovw cur rent ^^peFat'on 6tQi20VOC unfeguflaEefi al 5ma
Low dlsiortfDT^, low Impetianee. adiustaDfe sin^ave outpui [} la J vons peak id pean
Cf^ial conucjlled lor ti!gt> accuracy.
TTansinmef prr guEpul tio key ifansmiti^f while ID is Wing sem) ts an open ci3F|«H)r
T!^n£i&tDr thai will handle 3D VHC at 30Qma.
?ield aro^rammahle wim SU PPL I to KaytXHrd
CqnlirmaiiQn tone To mdicaie accipted WTArmv. pkJS Iwes le Imfhcate pragoinming ermr
All f3-togtaTvnin|i *s sic^d in a rwn-volstile tEf'ftOWl wh<h msy tiE aUsfic at ar^ time.
Messa^ iengiti over ?Q0 clvaraciers long
' i^ge^ ID with active tiigh or icm,
mm ID witti active fiigti or low W^l hojd ofl ID umii thafinei is ctear of tmfic
Gene^ale^ rppoaie^ min&iiY tsfii al end d u^f tiansmssidfi if etiabted
DvHitiie siffid iai>e ^d mauntHig turdwara supfiliKl tor qwcR mauiilau}.
qp^raiing ternpsratuiv range -30 tiepttS C to -f-GS degrees C
fwU one VEST wammy wfien KtyTp^ t& rf»e factory lor lepait
icrmediatt one tipy (Wttorv
Programmable Features
1 z-\. e satocniri? messages
:iv spe&i ftpn f to S5 wm
ID tnl^rvg$ Uner ^sm f-99 tan/m
ID tvie otf tum^ from th99 seconds
DV itwv im'-J^f^ trnnt fOOtvm 3000 Hi
frj^ porcA ^$igy mtenai tram 0 to 9$ secaoCs
€W Of MQHf cp»3Xon
$89.95 each
programming keyboard induded
COMMUNICATIONS SPECIAUSTS, INC.
42^ WiST mr r AiflhiUl * ORAHGE CA 32^5-^2 Jt
ill*} 9*S 102} * fA I /T4; 574 J420
Eittirt US.M. tMOi SS40%47 * FAX (SOO) 4243420
Subscribe
to
73
Amateur
Radio
Today
Call
800-
289-
0388
aaaiainD
W WBBELK/m
VIDEO I.D. BOARD
•Custom Graphics with your Call Sign
•4 Screens (2 Hi-res/2 color bar)
•12 VDCOperatJon
•Inslant Video ID
•Video Relay for switching in Live
Camera Video
•Built-in Automatic Sequencer-Timer
(steps through all four screens)
VDQ' 1 with pre*prograTnmed calls:
$99
CsUor wnt€ for catalog of avaiiable graphics
ELKTRONICS
12536 T*R. 77 • Fmdiay, OH 45640
(419)422-8206
EUCnONICS
wa^ssK
12536 T-B. 7?
fmdJig, OH '15310
t-l^l 422 Ute
anCl-E 10 ON ftEADEH SERVICE CAHO
ORCLE g OH READEf? S£ffVICE CARD
73 Amateur RadfO Today July, T994 65
^^TH^ 6/32 Brass Screw
r
6/32 Nut
Ground Folf
r
Teflon
PC Board
,i.\A.-j t'^A I ■■--■J -. hfj I bVd" I 'iVj- ■ 'aVj'i WUUTh.
3/16"
W
P/0 Stripline
Brass Pfns
1/2" Plumbing
Brass Pipe Cap
Solder
^
Ground Foi!
PC Board
P/0 stripline
From Filter Ends
Figure 3. Pipe CBp filter construction for 10 GHz operation. The brass pins are 3/16" long inside cavity. Round Tefipn insuta-
tor 1$ slipped over the pins to hold them vertical and to insulate from the cavity and the 6-32 screw.
Prepare the top of the pipe cap by
drilling a hole in the top center of the
cap. Tap for 6/32 threads and solder a
brass nut over the hole. I used a steel
screw to facilitate this operation, as
the steel screw/ will not take solder
welL The steel screw is to be used as
a centering tool. The idea here is that
the steel wtii resist the soldering oper-
ation and only allow the nut to be sol-
dered to the top of the pipe cap as-
sembly (centered on the hole drilled
for the 6/32 screw). After the solder
cools, the steel screw can be removed
from the cavity. A brass 6/32 screw
with a nut run up on the screw is
placed into the cavity top. If you are
not sure what kind of screw you have.
test it with a magnet. I am sure you
will identify many different screws that
you thought were steel or plated steel
and you'll find that they are nonmag-
netic and are most likely plated brass.
Any of these are OK to use for cavity
retuning. See Figure 3 and Photo C
for pipe cap cavily details. The design
is rather forgiving In the positioning
and length of the probes and frequen-
cy resonance. The loss of the filter
and coupling will be affected by probe
length. I find about 3/16" to be a good
choice for probe length.
When soldering the cavity (about
and Insutated from the coupling pins)
To the PC board position, (use some
iorm of sleeving on the pins to ensure
they stand straight up and are insulat-
ed from the cavity side wall. Be ginger
with solder in this application and try
not to get solder inside the filler — it's
very lossy at microwave levels. Don't
overheat the pipe cap as components
on the other side of the PC board
might unsolder wltft too much heat.
Tack-solder the cavity to the ground foil
over the probes, near your planned ink
line drawn on the opposite side of the
board. An exact fit is not necessary;
just center the 6/32 screw about the
center of the probes and keep the cavi-
ty side wall off of the probes. If the cav-
ity wall touches the Teflon, that's OK.
As you can see from Photo B^ the
finished multiplier assembly I made
used scrap copper PC board material
to fashion a case for the multiplier II
also made it quite easy to attach coax
connectors to the very soft Teflon PC
board. This gave the board a rigid feel
that made modifications and opera-
tions easier on the workbench, During
the re -adjustment step of modification
I found that most of the gain improve-
ments to the circuit were made on the
EMITTER LOCATION
Direction Finding System
Tracks Down
• Stuck Microphones
• Cable TV Leaks
• Jammed Repeaters &
Cell Sites
Models available with
computer interface,
synthesized speech,
for fixed or mobile
use, covering 50 MHz
to 1 GHz, Call or fax
for details
RADIO ELECTRONICS
AND
COMMUNICATION TECHNOLOGY
MADE EASY— NO SHORTCUTS!!
> FULLY UNDERSTAND THE BASICS—
STEP-BY-STEP
^ BOOKS PACKED WITH DETAILS, EXPLANATIONS
AND ILLUSTRATIONS— EXCELLENT FOR SELF
AND CLASSROOM STUDIES:
1. Matter, Energy, and Direct Current
2. Alternating Current and Transformers
3. Electronic Tubes and Power Supplies
4. Solid State Devices and Power Supplies
5. Amplifiers
6. Wave-Generation Circuits
7. Propagation* Transmission Lines and Antennas
8. Amplitude and Phase Modulation
9. Microwave
PURCHASES OF:
• 1 TO 2 BOOKS:
• 3 TO 5 BOOKS:
•6 OR MORE:
$12.95 + $1.50 S&H (EACH)
$1 1 .95 + $1 .00 S&H (EACH)
$10.95 + $ .75 S&H (EACH)
(FOREIGN ORDERS INCREASE S&H BY $500)
30-OAY IVIONEY-BACK GUARAfSlTEE (MINUS S&H)
yCA/ISA ACCEPTED (INCLUDE NUMBER AND EXPIRATION DATE)
SEND CHECKyy.O. (NO C.O.D.} TO:
LATHROP PUBLICATIONS
P.O. BOX 207
UPPER MARLBORO MD 20773
CIRCLE 13 ON HEADER SERVICE CARD
CIRCLE 197 ON HEADER SERVICE CARD
66 73 Amateur Radio Today * July, 1 994
muftipJier stage. Initially. I connected
aljoul +5 dB ® 2.55S GH^ lo the mul-
tiplier input and tried to observe output
at tO.5 GH2, the Mh multiple. I ctieat-
ed arid used a t>encti oscillator for this
reluning !esl and ixri the modified syn-
fiestzer (versatjiity and test contiD^K
I connected a power meter to the
oytput and found almost notfilng for
power out (less Ihan -20 dBm). I start-
ed to tune the pipe cap fiTler (inserting
Ihe screw tnio cavity), and as I did the
power irxjf eased. I tuned the tiller for
the best power output I could obtain
and it was at>out a -6 dBm. I took a
took on the spectrum analyzer and
found out that the freqttency was what
I wanted, and further identified that the
f titer would only tune to the fourth har-
monic^ nrtaklng the conversion of the
filter quite easy. In other words, I was
quite Jucky. With this in mtnd, I am
quite confident that you will not need a
spectnjm analyzer lo make modifica-
tions as only a microwave power me-
ter Is needed.
To bring the power up 1 applied the
standard *'snow1lake" copper tuning
tools to the PC t>oand lo find hot spots.
Fof those not familiar with tuning mi-
crowave circuitry and "snowf taking,* I
am referring to using bits of copper
maler^al to be moved about the RF
portkxis of crrcuit boa^ to retune the
CirctiiLry. Instead of moving tjits Of cop-
per about the board much like a
shuffle tx>ard, constaict some loots \o
do the job tor you. The tuning tools are
made by super-gtumg small bils of
copper foil to toothpicks. I used rour>d
tooihpicks and cut off one end to
make a slight flat spot to sdhere the
copper bit 1o^ Make several of various^
sized copper bits. I started off by get-
ting some ooppef foil (from bobby or
modef railroad stx)f}s} and cutting it in*
to miniature pieces about 0.050 to
0.100 square — the exact size is not
importanr E usitaliy close my eyes and
chop up a small piece of copper foil
and then seEeci what I want from the
cutoffs. Some of these bits wili be at-
tached to toothpicks, and the others
will da soldered on the PC board
traces, duplicating the size and posi-
tion that the toothpick "snowflake'' test
produced.
When moving the tools about the
PC boardp keep the DC power on and
be careful not to short anything out-
go slow. Remember to turn off
DC power when you soJder copper
bits lo the trace, with a duplicate bit
of copper as indicated by the tuning
tool, on a hot spot. These hot spots
found in the *'snowflake test" are
places where you either add or re-
move copper from the existing Irace. If
by coming near a trace the power re-
duces, this mighl indicate that you
need to remove copper foil or modify
the trace at this point. El's like the drop
in power is saying^ "I don't want any
more copper circuitry (in the form of
traces) ^ but l want less, so remove
some (copper foil}.' In some cases the
width of a PC board trace need be re-
duced.
When making any changes, do it in
a slow methodical manner ar>d do rrot
make large changes; go slow — a few
thousarxJths at a time — and check for
chartge. The rule is: wide traces, very
low impedance: narrow traces, very
high impedance. A 50 ohm trace on
this type of PC board is about 0.035'
wide or so. My hedge on this Is that I
don't Icnow the exact dielectric con-
stant for the materfal lo cak:ulale il ex*
actfy. so this is an estimate. As an ex*
ample. 100 ohms = 0.015% and 20
ohms = 0.100" wide.
If, on the other hand, power In-
creases when the area is approached
by moving the toothpick with a copper
bit attached, add copper to this area.
Be careful to not short out traces with
the copper bits as DC power is on
when you are testing with the tooth-
piclc tools. When you add or remove
traces to the board, turn off the power
and use a static-free work station and
grounded soldering iron, A tempera-
ture-controlled iron is the best iron to
use. They operate from low voltage
DC and are usually grounded. Static
and high voltage soldering irons can
produce enough voltage to zap a sen-
sitive GaAsFET device. To minimize
static a! my work station, I connect a
groutnd wire frnm my iron's ground to
the work piece, a copper circuit t>oard
that serves as a common grounded
work station. Don't forget the wrist
Strap with a bufJt-in high resisiance
discharge path. The high resistance is
there for your protection, as well as lor
static elimination. Ground Ihe PC
board with a dip lead to Ihe common
wofKpiece, Everything at common
ground should eliminate any static
problems.
In hindsight. I found that most of
the gain improvements were rnade in
the multiplier stage of the PC board, I
obtained a +7 dBm output at 10.220
GH2 by using a drive source at 2.555
GHz. No retuning was necessary in
the 13.1 GHz stage to obtain this re*
suit. More power or better efficiency
could be obtained by retuning the 13.1
GHz stage. I just stopped the modilk
cation without retuning this Stage as
+7 dBm power was all that was need-
ed for E good mixer Injection level, If
you want to re-tune the multipfier's
amplifier go about it in the same n^n-
ner as the multiplier stage.
Well that s il for this month. As al-
ways. I will be glad lo answer ques-
tions about this topic and related ma-
terial Please Send an SAS£ for a
prompt repJy. Next month I will cover a
surptus Loran receiver that can be
computer-operated to give you Lat-
tong positions and convert them to
six 'figure grid squares for grid-square
hopping. 73 Chuck WB61GP
Numt>er 22 on your Feedback card
H^^ numtter Z2 on your PeeooacK
Dealer directory
DELAWARE
New Castb
Factory authorized dealer! Yaesu, ICOIVI,
Kenwood, Ten-Tec, AEA, Kant rentes, DR-
Si Mfg., Amerilron, Cushcraft. HyGaIn,
Heil Sound, Standard Amateur Radio,
MFJ^ Hustler, Diamond, Qutlernut, As-
Iron. Larsen, and much more.
DELAWARE AMATEUR SUPPLY, 71
Meadow Road. Hew Castle DE 19720.
(302) 321-7720,
NEW JERSEY
Lodi
Norlh Jersey's newest Two Way Radio
and Electronics Dealer is now open.
Sates of Ham, Business. Manne and C.B.
two way equrpmem as well as Scanners^
Shortwave. Eleelfonic K^ts, Antennas,
Boohs, Cable Bojtes and more. Friend ty
service and low pnces. Advanced Spe*
cialties, 114 Essex Street, Lodi NJ
076444201) VHF*2067.
NEW JERSEY
Parl( Rpdge
hforlh Jersey's oldest and Fnest Short-
wave and Ham Radio Deafer. Three minr-
utes from Garden State Pkwy and NY
Thmway, Authorized Dealers for AEA, Al-
pha Oe^la, Diamond. fCOM. Japan
Radto Company. Kenwood. Vectrorrics,
Yaesu, Ham Sales, Lee WK2T GILFER
SHORTWAVE, 52 Park Ave., Park
Ridge NJ 07656. {201J 391-7887.
NEW YORK
Manhattan
Manhattan's largest and only ham Radio
Store, also full Eine of Business, Marine,
Aviation, Shortwave Radios arvd Scan-
ners, and Cellular Phones and Beepers.
Large selection of Books. A/itennas, Test
Equipment, coaxial cable and parts. FuU
Service Repair Lab on premises. Our
44th Year . , .We carry all major lines:
MOTOROLA. 1C0M, KENWOOD. YAE-
SU, 8ENDIX-KING, ASTRON. AEA,
SONY. PANASONIC, MFJ, CCTV CAM-
ERAS AND MONITORS, BIRD
WATTMETERS, FREQUENCY COUN^
TERS, SCANNERS, HYGAIN, VIBRO-
Pl^X, HEIL, CALLBOOK. ABRL. OTH-
ER PUBLICATIONS. Open 7 days M-F,
9-6 p.m.; Sat.. 10-5 p.m. Sun. 11^ p.m.
We ship Wortifwide, Call, Fax, or write for
infoirnation and prices. Your one Source
for HAM arxJ Business Radios ., , BAR*
RY ELECTRONICS, 512 Broadway.
New York NY 10012. (212) 925-7000.
FAX {Z\2) 925-7001.
OHIO
Cofumbus
Central Ohiio's fuiJ-^ine authorized dealer
for Kenwood. ICOM. Yaesu. Ahnco.
Japan Radio, Standard, AEA, CtistKraft.
Hustler Diamond and MFJ. New and
used equipment on display ^nd opera-
tionat in our new 10,000 sq. ft. facility.
Large SWL Department, too, UNIVER-
SAL RADIO, 6830 Americana Pkwy.,
Reynolds burg (Cotumbus) OH 43066.
t§14}8€&-4267.
PENNSYLVANIA
Trevose
Authorized factory safes and service
KENWOOD, iCOM, VAESU. featuring
AMERITRON, B&W, MFJ. HYGAIN,
KLM. CUSHCRAFT. HUSTLER,
KANTRONIGS. VIBROPLEX, HEIL,
CALLBOOK, ARRL Publications, and
much more. HAMTRONICS, INC., 4033
Brownavllle Road, Trevose PA 19047.
(215) 357-1400, FAX (215) 355 8956,
Sales Order 1-8O0-426'2S20. Circle
Reader Service 298 for more information.
DEALEHS: Vo-jf OCKtipany natue arid me$sags can. contain up bD SO «Ofi}S lor as iitlle is S4-20 ye^ ttrepatdi or S2l0 'tv &s
mor#« eiif«p9id) t^^ mer^ian d nwhcxriertxBne&s pius«. Oireoo^ ^ vd ptymint mj^ reacti us iS days n advance tit
PMUcilorL Fd' cxanpic. advertising tar tie Apri ^ ss^ must oe n Otf fmdi 1^ Aiy ist US' b 73 Amsisi/r Ra^ TiOaf
70 fit. 202 h. Pm^tXfO^, tH C3458.
PC HF FASCIMILE 7.0 $99
IKiiJJ
II -11^ I
CCl
MM .flit
' Irlf
. JMIS
^■T^'
tH**^-^
I'tV" ,
InliXI
-vr^.1
!'^T:
> ^s.^HV4A'
-*" V-
■.^y
Now under Windows or DOS
PC T^ Facs^nie es 4 mm^. V«( cof7ipret«nsivt tfiortwsv« ta?( $ys£em for the ISM PC amS oomptfctw
iiiami^ Wlh ^'Qkj' PC ani SS8 r«^«<^« QflCthQFAXhiifnB{kHa(9a«}uit»rn0 of ma te4tur»
tih>
McHiH or M«mj O^Hr*f>
Un«{t«nd«d OpftrttfOA
itty Tuning 0«clllcneopH
Start Stop' Ton* necognttioii
Up !□ ^S6 Lftvels
Sir\q\^ Scan per Liiw wifth EMS Mtmory
Pr^rf mmable Co^crlzation
Brightness and Cantrait Conlrol
Trans [Tiii OpiLan Available!
Image ZdoiHh Scroll, Ptn, Rotillon
Gfiyvcaie on «ll Pofsglar Prlntan
Worfdwidt QroAdcati Schadul*
Wo^'Mlde FfeqLhency Liaijng
CGA,HGA.SGA,VGA A $upw VGA
T1ni€ Lflpa« Frame Looping
Slides ho wi
Prografrmiit>l« IOC A Una nuas
image Croppln9
Automaik:^ fijidio Control
NAVTEXT & RTITY Dpllon AwHlblt
CtU or vvr^e lor our tree uialog nl producli. Vtu A MtitefCard wwicoma.
Software Systems Oonsulting
615 S. El Camino Real, San Clemente, CA 92672
Tel.(714) 498-5784 Fax.(714) 498-0568
CIRCLE 250 ON READER SERVICE CARD
73 Amateur Radio Today* July, 1 994 67
Ask haboom
Number 23 on your Feedback card
Your Tech Answer Man
MtcfmeiJ. G^er
c/o 73 Magazine
TO Rout& ^2 Nofih
Pmefttorougti NH 0345$
Getting Clipped
Radio as we know it today is an
analog medium. Oh, sure, there's lots
of digjia! control, and some digital sig-
nal processors have begun to appear.
Still In the end w© mod ui ate a carrier
of some sort with some kind of analog
informalton. even when we actually
want to send digital data. The possible
exception is CW, aithoiEgh that's de-
batable. But what exactly separates
the digital and anaFog universes, end
what happens when you push them
beyond their limits? Let's take a look
at some of the ways, both analog and
digital, to represent irifonr^ation. and
then e^amtne the consequences of
overdnving, of ^clipping,' thenrL
Squash
Ju$t what Is cfipping? WelL imagine
yoy're a dfOjit of some kind. You have
limits, beyond which you just can*t
give any more. Along comes this sig*
nat which is so strong yott canT haodte
it an. Sa. you give as much as possi-
ble and. when the s^nal goes out of
bounds, you just stay at your output
voltage jimi! unlrl it comes back within
your rarige. II we now graph your out-
put or look at it on an oscilloscope, the
highest and lowest points will be
squashed flat, or clipped. That's seri-
ous distortion, and it has differing con-
sequences, depending on what's be-
ing clipped,
In an analog system, information is
represented by a changing signai
which in some way mimics what you
want lo send. There are various ways
to do that and each behaves different-
ly under clipping. Let's iook at a few.
Baseband
You may have heaid this term used
to describe many kinds of signals. But.
underneath an the definitk)ris, such as
video* data or audio, lies a common
C^jncepl. Baseband refers to tiie or>gi~
nal modulating signal, before it ^ im-
pressed on something else. So, in a
stereo system, bastard audio is just
plain audio. In other words, it is not
digitized. FMed, or whatever-ed. In
video. It refers to the vtdeo signal as it
comes from the cameran VCR or other
video source. Especially in video,
where RF modulators are common,
the term reaiiy helps lo keep things
straight: ts this switch handling base-
barxi or RF? In radio ^ baset>and refers
to the signal you wish to send, or the
one you've received alter demoduLa-
ttorv
Sometimes, though, the definition
can get murky, Lefs say you receive
an SSTV signal on 20 meters. Out oi
your speaker come the warbling tones
which represent a picture. Are they
baseband? Well, as far as the radio is
concerned, they are. because they are
demodulated audio. But, SSTV is sent
as FM. meaning that the frequency of
the warbling tones Js proportional to
the [nstantaneous brightness to be
displayed on the TV screen. So^ we
don't really get to baseband video until
the SSTV converter's FM circuits de-
mod ui ate the tones into a varying volt*
age representing the picture elements.
That voftage fs truly the ""b as e band"
video signal aibeit slowed down Even
more confusingly, the time -con verted
video signal actually sent to the TV
monitor is also baseband video fast-
scan video.
When yoo clip a baseband signal,
its lops and botloms get flattened.
With audio, it sounds like tremendous
distortion. With video, it disturbs the
sync pulses, which are at the bottom
of the signal, arxJ it turns high -bright-
ness points, such as facial h^hlights,
to white. The sync disturbar>ce can re-
sutt in wiggly pictures which tear and
roll as the scene changes. ATVers of-
ten have to wrestle with this problem,
because ft is hanj to make RF transmit
amplifiers which stay completely linear
frofTi edge to edge.
AM
This ts one of the easiest modes,
yel still one of the most complex. The
modulating signal changes the
strength of the earner. Seems simple,
right? At first, thai appeared ali there
was to it. After a short time, It became
dear that much more was going on.
The concept of sidebands, in which
the modulation appears in mirror im-
ages on either side of the carrier's fre-
quency, was not immediately believed.
It took quite a bit of mathernaticaf de-
velopment, and significant measure-
ment and obsen/ation, before the side-
band theory was accepted. Even now,
you can hear debates as to exactly
how much power is going into the
skfebands and how much into the car-
rier, which is presumed not to actually
change strength, despite how it looks
onaso^pa!
Clipping an AM signal has drastic
consequences. The amount the side-
bands spread from the carrier de-
pends on the nnodulating frequencies.
When we clip, though, the rale of
change of the earner at the moment of
dipping becomes very high, implying a
PCB / Schematic CAD - from $195
EASY-PC - For single sided and
multiiayer boards to 1 7"Jtl7'.
Phenomenally fast and easy lo use.
Over 1 8,000 copies in use worldwide.
EASY-PC Professional for boards up to
32" X 32" at .001" resolution, 16 layers.
Schematic capture and netlist extraction -
integrates seamlessly with PULSAR and
ANALYSER ML Runs on PC/XT/AT/
lUm^fAB^ with EGA or VGA displays.
Logic Simulation - from $195
PULSAR and PULSAR Pfofessmnal -
FutI featured digital logic simulators
Allow you to test your designs quickly and
inexpensively without the need for
sohisticated test equipment
PULSAR can detect the equtvatent of a
picosecond glitch occurring once a we^kf
Runs on PC/XT/AT/ 2fi6/3S6M8S with
EGA or VGA displays,
Analogue Simulation -from $195
ANALYSER til and ANALYSER 111 Pro.
Powerfui linear circurt simulators have full
graphical output, handle R's,LXC's, Bipolar
Transistors. FET's, Op-Amp's, Tapped
Transformers and Transmission Lines etc.
Plots Input and Output Impedances, Gain,
Phase and Group Delay. Covers 0 001 Hz to
>10GHZ. Runs on PC/XT/AT/286;3SeM86
with EGA or VGA displays.
For information write, fax or calt:
Number One Systems
REF: 73, 1795 Granger Ave., Los Altos, CA94024
(415)968 9306
VISA and MasterCard welcome.
AMATEUR TELEVISION
TVC-4G
Made in USA <5"'y $89
SEE THE SPACE SHUTTLE VIDEO
Many ATV repeaters and individuals are retransmitting
Space Shuttle Video & Audio from their TVRO's tuned to
Satcom F2-R transponder 13 or weather radar during
significant storms, as well as home camcorder video. If
it is being done in your area on 70 CM - check page 461
in the 93-94 ARRL Repeater Directory or call us, ATV
repeaters are springing up all over - all you need is one
of the TVC-4G ATV 420-450 MHz downconveters, add
any TV set to ch 2, 3 or 4 and a 70 CM antenna. We
also have downconverters. antennas, transmitters and
amplifiers for the 400, 900 and 1 200 MHz bands. In fact
we are your one stop for all your ATV needs and info.
Hams, call now for our complete ATV cataloguel
We ship most items within 24 hours after you call.
CIRCLE T ON READER SEHWCECARD
(818) 447-4565 m-t Bam 5:30pm pst. Viet, MO, COD
P.C. ELECTRONICS T«n{WBORG)
2S22 Paxson Ui Arcadia CA 91007 Miryann (WB6YSS)
68 73 Amateur Radio Today July, 1 994
much higher modtiratiorr frequency
Ihan is actually present. That resutts in
all kinds of sidebands very far from the
carrier, which we call "splatter" li*s a
mesSp both spectrally and legally.
SSB
Sideband, which Is a special form
of AM. suffers from the same prob-
lems when overdriven. But how oan
we ciip a carrier when there isr^'t one?
Well, remem&er thai we are generat-
ing an RF sigraal ar>d then making rt
cancel ttselt out in the modulator. The
object 3s to create sidebands, one of
which we then throw away and the
olher of which we send on to the an-
tenna. If we clip the modulator, It gen-
erates the same kinds of false sid^
bands we'd get with AM, and we wirxJ
up sending those on one side Of
course, the sideband filter will keep
the extia-wide ones in check, But^ if
Uie clipping occurs in the final ampli-
fiers, the mess makes tt to the anten-
na because it happens after the side-
band filter.
FM
Is it possible to dip an FM transmit-
ler? [n theory* no. After air, we're just
higgling a carrier's frequency back
and forth, so there should be no limit
as tc how wide we make rt. in practice,
though, the drcuit stages have t>and-
width limits. When we deviate the sig-
nal far enough to run into those, ihey
will begin to cut the signal off as it ap-
proaches the outside points. The re-
sult is an *AM-ing* of the signal as its
strength goes up and down, along with
AM-iike splatter arid distortion.
The FM receiver is a special case.
Its cfipping points are set by the IF
bandwidth and, especialty, the detec-
tor bandwidth. If the transmitted signal
ejfceeds the IF bandwidth, it'll get AM-
ed just like it would in the Iransmitter
example. If the signal exceeds the lin-
ear bandwidth of the detector, it'll dip
the audio just as it It were an overdriv-
en t^aseband amplifier.
with nice, flat ends. Of course, ifs a
kind of serious distortion, t>ut does rt
matter?
Not In this case. Remember, with
FM the information Is in the wiggling of
the carrier's frequency, not in any am-
plitude changes. That frequency will
survive the dipping process Just fine.
In fact, it'll be the only thing left, whtch
is just what we want-
By the way, that njshing noise you
hear when there's no signal on an FM
receiver is caused by the same pro-
cess; the small amount of internally
"Baseband refers to the
original modulating signal,
before it is impressed on
something else. "
There's one place, though, where
clipping is deliberately empEoyed In an
FIVI receiver in order to reduce sus*
ceptibllity to impyise noise and other
amplitude phenomena. In fact, this
kiFKl of clipping is what is responsible
for FM's inherent superiority to AM in
that respect.
The basic technique Is to posh tfre
IF ampHfiers beyond their linear limits,
forcing them to dip. That flattens any
noise spikes or other changes in am-
piitude riding on the received carrier.
What's left is just the carrier signal.
generated noise in all circuits is ampli-
fied by the dipper (also called the "llm-
IteO to the point where it wings from
rail to rail (the upper and iower limits)
and is detected as random noise.
Inter mod
Tntermod is caused by clipping,
usually in the front erxl of a receiver.
The overloading signals cause Ihe
front ^end ampiifier to distort, creating
all kinds of sidebands of its own.
Those then look like phantom signals.
Aiso. clipping causes mixing of other-
wise-unrelated signals, causing odd
blends of them all over the dial. And,
when a very strong foreign signal is
present at a transmit antenna, inter-
mod can occur in ihe final amplifier of
the transmitter, making it broadcast
the mess all over town, or even all
over the wo rid. If you don't believe me,
ask any urtian repeater owner.
Well, t hope you've enioyed getling
clipped in the analog domain. Next
time, we'll take a kiok at wfiat happens
wlien signals clip in digital circuits.
Now. let's look at a letter:
Dear Kaboom,
I have two mobile 2 meter rigs.
With a strong signai, they're both fine.
But. when I listen to a weak signaL the
older one always seems to pick up lots
of ignition noise, white the newer one
doesn't hear it, even when I use the
same antenna. Is the slaticky one bro-
ken, or can I adjust it somehow?
Signed,
Headache #12
Dear Headache,
What a relevant letter for this
month's discussionl No, neither of
your hgs is brok^. and there's r>oth-
ing you can adjust. The quieter receiv-
er has better-designed IF clipping
stages, so it rejecls more AM, which is
what ignition noise spikes appear to
the rig to be. Tm afraid you're stuck
with it.
Until next time. 73 de KBIUM.
QUALITY THAT'S
AFFORDABLE
Tri-Ex is pleased to announce the reduction in price on
the most popular models of quality Tri-Ex towers for the
Amateur radio enthusiast. The overheiming acceptance
of the listed models has made it possible for Tri-Ex to
pass on substantial savings to our valued customers.
LIV1-4/U $3^945 $3,658
Was Now
WT-51 $1,245 $1,050
LM-354 $1,865 $1,300
7]w LM-35* is suppiie<i wji a hand wincn brake system The LM-470 is moton?^.
H
TO ORDER CALL
800-323-2393
TECH SUPPORT 209'65 1-7859
FAX 209-651-5157
All towers are complete with rigid concrete base mount and
rotator mounting plate. Tri-Ex piints and calculations provided
with tower are comptiant with 1991 Uniform Building Code
(U.B.C.) Engineering designed to 1991 U.8.C. - 70 MPH
iri*
®
TOWER CORPORATION
71 82 Rasmussen Ave. * Visalia, CA 93291
Unsurpassed Quality since 1954
YOUR HAM SHACK
Next two issues of PolyPhaser's
^ Striking News (newsletter)
V will cover proper shack
grounding and
protection
techniques.
to receive
your free
, copies
i contact
tMmmit'
(800) 325-7170
2225 Park Place
CORPORATION
^82-2511 ■ FAX;(702) 782-4476
MInden.NV 89423
(702)782-2511
I P.O. Box 9000
CfRCLi 22 ON 8£AO£B SERVICE CARD
CIRCte 49 QH READER SERVICE CARD
73 AmBfeur Radio Today* July, 1994 69
Number 24 on your Feedback card
^^p ^^ Number m on your heeoDai
73 INTERNATIONAL
Amie Johnson NIB AC
43 Old Homestead Hwy.
N.Swan^ey NH Q3431
Notes from FN42
Before t started the column this
month, 1 just had to reread the report
from the Peter i DXpedition written by
Peter ON6TT. He has such a great
sense of humor spread throughout the
report- i just wish that we had the
space to print it alt.
Another MothQfs Day approaches
as t sm working on this column, which
means that HosstraderE is just a few
days away (the Friday/Saturday of
Mother's Day weskenO). it is another
^'great happening' similar to Dayton
and others, but mostty taitgating out-
of-doors.
There is much forafi—onB person's
junii is another's treasure, it is reaify
something to just sit back and watch
the smiiing faces go by iuggtng a 'boat
arTchor" from days past- You've proba-
bly seen that same boat anchor go by
during past Hosstrader's. too, if you
matty kept track
t've already be^n given my ''march-
ing orders" from headquarters (my
XYL): "No new stuff unless you get rid
of some of the old stuff ^ She's said ft
in the past, and this time she really
means it! If you saw some guy crying
as tiB unloaded some of his "trea-
sures' at bargain pric^, tl was proba-
bly meL I hope that you were one of
the lucky ones to get or^e of my trea-
sures.' 73 'tit next month. — Arnie
NIBAC
Roundup
Brazil From the WWSA News —
Jart/Feb 1994: The Bfazilfan magazine
Antenna-Bectronica Popu/ar invites all
amateurs worldwide to participate in
the 13th edition of the well-known
WWSA CW Contest,
The contest is hefd on the second
fufl weekend in June (June 11-12,
1994] staning on Saturday al 1500
UTC and lasting until Sunday at 1500
UTC. A separate log for each worked
band must be sent no Jaier than July
31 to: WWSA Contest Committee, PO
Box 2S2. ZIP 20001-970, Rjo de
Janeiro. RJ -Brazil
Germany From the Deufscher Am-
ateur Radio Club (DARC): How to Ap*
pfy For a German Short-Tenn Air^ateur
Radio Licence: Licenced foreign ama-
teurs staying temporarily in Germany
(on visit or in transit) may obtain a
shoft'temi amateur mdio flee nee from
the Deutsche Bundespost. valid tor a
period of three months, by directing
their application, at least six weeks in
advance, via Deutscher Amateur Ra-
dio Club, tniernattona! Affairs. Post-
tach 11 55. W ' 3507 Baurtatal 1. Ger-
many to Oberpost^rektion Dussetdorf .
Licence fee ar>d handling costs for a
three-months' ficence amount to
0M15 {deutsche marks). This sum
should be iransferred, at the same
time as the appilcation Is sent, in Ger-
man currency (no IRCs. no stamps
please) by postal money order to;
Postscneckkonto (postal cheque ac*
count), no. 56 13-430 at Postscheck-
aml Essen. BLZ 360 100 43, for
DARC — Iniernational Affairs — w —
3507Baunata[1.
A German licence will only be
granted if the applicant possesses a
valid amateur radio licence of his na-
tional administration which is at least
equivalent to the German licence
class requested
in the application, the following
should be given: 1) Nationality of ap-
plicant; 2) FifSt name and sumame; 3)
Date and place of birth; 4) Home ad-
dress; 5) Home catlsign. class of li-
cence; 6) The three months' period re-
quested; 7) Address of location of op-
eration; 8) Address to which the li-
cence document Is to be sent; 9) Con-
firmation that the licence fee has been
forwarded to the Postscheckamt Es-
sen (photostat of payment slip): 10)
Photostat of your hoit^e amateur radio
licence, together with an indication of
the date of issue and duration of valid-
Sty, class and comparable German
class of licence (Class C— 144 & 430
MHz only: Class B— All HF band fre-
quencies and 144 & 430 MHz; Class
A— 3520-3700. 21090-21150. 28000-
29700 kHz, 144 & 430 MHz.); 11)
MerBtMrship in a national amateur ra-
dio society (yes/no), and the name of
the society. German short-term ama-
teur radio licences are issued to for-
eign amateurs for periods of three
months only, beginning on the first day
of the month, as requested by the ap-
plicant The shoft-term licence will en-
IJUe the foreign amateur to operate a
Fixed, mobile, or portable amateur sta-
Peter t Info from Peter 0N6TT, Eu-
ropean Coordinator 3Y0Pt: There was
excellent propagation during the first
days of the operation. Europe was
coming in fairly weak during the first
weel^. which was of major concern to
us. Propagation was very unpre-
dictable. Sometimes we could wofk
EU on 20m, from 0400 on. while the
r>ext day we couki rot hear them at aJt
during the EU-moming. Sometimes
40m to EU opened up at 0000, some-
limes as i ale as 0600. During the sec*
ond week (excluding the weekend, un-
fortunately), signals from EU were fair-
ly strong, but it Seemed that despite 2
kW and yagls. EU could not receive us
very well.
30m was a disaster. TT>e band was
alrrm^t completely covered with South
American SSB pirates. On 40m and
90m we had problems attracting EUs*
attention, especially in SSB. We woukl
hear very strong signals, but could not
get anyone to answer us Jn that case,
we answered somebody's "CQ DX"
(most of tt^ time he would not believe
it was us answering his call) and
asked hfm to look for a frequency
ciear for us to transmit on. Normally,
this worked. Reception on the low
bands was very good, though {no
man-made noises). We had only one
good opening to EU on 1 60m.
After one day of operation, we
found that stateside would cover up all
EU signals, so we favoured EU from
the moment we could hear them.
Sometimes, we tried 10 work very
weak EU-signals, leaving 9+30 USA
people waitJr^ for a while. Neverthe-
less, we could not leave any continent
waiting for too long a time, so some-
times it could happen that you would
hear us wiih weaker signals working
the USA^ and not working Europe.
And believe me. this was not easy We
held statistics on what continents were
worked on what bands and modes, so
we would give everybody an equal
chance for as many band modes as
possible.
Uving conditions: We had two oper*
atlng shelters of 8 x 8 ft. (one CW and
one SSB), a kitchen shelter of 8 x 12
ft, (used lo sleepH awaiting evaouation
of the island), and a sleeping shelter
of 12 X 24 ft. Shelters were wamied
with propane heaters (siic boltfes of
100 kg propane each). Our separate
top-open toilet shelter with a home-
made toitel seat proved to be very
useful (but we had to count on digging
out five feet of snow before 'taking a
sit^.
Power: Two 4 kW Onans and two 5
kW HcmdaSn with 14 barreis of gaso-
line (200 lifers each). Don't wony if the
I
I
Factory Authorized Dealer & Service For
KENWOOD
YAESU
ICOM
Call U9 For
Great Prices & Great Semlce
TOLL FREE ORDER LINf 1
<«0CI-M4.31#4
theH^M
CENTER
AMATEUR RADIO s^ia/i r
FAX (SI £1647-9007
I
41 l/^C 100 PAGE
lUIJlC CATALOG
t CommuniGations Receivers
Portable Receivers
Scanners
I Amateur HF Transceivers
VHF'UHF Transceivers
HT's and Mobiles
Amateur and SWL Antennas
Accessories and Parts
RTTY and FAX Equipment
I Books and Manuals
This catalog includes prices!
Send
SI to
Universal Radio
6830 Americana Pkwy. 73
Reynoldaburg, OH 43068
Tel. 61 4 866-4267
THE FAIVIED 2 METER
Also the ultlmaie for scanners bcb to 1300 MHz.
A. s. A. 9209
+9 db Co- Linear "MultiWave" Base
Station Double 5/8 over 1/4 wave
delivers up to +9 db gain. All fiberglass
& solid aluminum construction. Fits
masts up to 1-1/2". 2 Meter Base
Station 1 0" length.
$36.73
+ $6,00 S&H
(SC HES. 5% SALES TAX)
CHECK IN ADVANCE OR COD.
ALSO AVAtLASLE IN 220 4 440
Model 9209
+9db
"Sfinfxx JA EAf fisAsaiy Far Ouf $i£ctss'
Tel ( 003)293 -rsas PO 3fli3<5l
wans: 1 '&M-72?-26fl1 Myrtle Beacfi . SC 29S?a
70 73 Amateur Radio Today * July, 1 994
3D - ANIMATED VIDEO
CALL SIGNS FOR ATV!
Best prices
• Broadcast quality
« Makes you look like NBC
• Custom designed for your station
* Available in tape format of your choice
Just pby from your VCR wht^n you want station ID.
Includes Morse Code nudio stjiuoc} ID also.
Send for sample tape at $5.00 + $2.00 S&H and
aim receive a certificate worth $10,00 discount
when you place your order.
Check, visa, master or discover card accepted.
CALL (612) 463-7702 for order or info;
STABLE-EYES™
P.O. BOX 53
FARMINGTON, MN. USA 55024
mm^
Pfffspyju: ODMPUTtff RfPfAffp DCwms>LL^fl
TU)
S^ie^^i4^ ^% ^?C^^^
^^^
^ F\m\\ Duplex Autopatdi
v^ 91 1 Emergency Access
^ Reverse Ausopalch /ToH Restfiction
-^ Voice Mail ^ Voice ID'S ^ BSR XI 0
*^Voice/Tone/DTMF Pagirvg -^Scheduler
•^ Links •ProgramfTiiable Courtesy Tones
i^ Hardware Logic I/O /HF Remote Control
•^ Morse Code Practice •^Remote Base
PCRC/2 Combineg the power of your
XT/AT platform with a high quality ptay and
record voice digitizer creating ihe ultimate
repeater controller. ^^^^^ ^695
51S-563-47r3
Fa^cSSB-^yw BBS: 28$^ 1st 6
CfRCLE 235 ON ftEADER SERVICE CARD
CIRCLE 136 ON READER SERVICE CARD
houp
Sell your product in 73 Amateur Radio Today
Call Dan Harper today. . . 1-800-274-7373
ELENCO • HITACHI • B&K PRODUCTS cautoTfree
GUARANTEED LOWEST PRICES
1-800-292-7711
1-800-445-3201 (Can.)
AFFORDABLE - HIGH QLfALITY
I YEAR WARRAKTY
ELENCO OSCILLOSCOPES
Hitachi Compact Series Scopes
20MHi Dual Trace
SOWN;. Cur^on;
V-^1^
V-5?3
V-660
V 1060' tttMIHcDidTrxx
SOMHr. Da-layed Sweep
bOMt^z. DC Offfi«r
40MH2, OC Offsai
WUhi, OC OJisel
aOMHzLDualTwa
V-1099 - ^OdUHt, OT, «ttnf!Hy
S-132S SSUKz SM9 S-13«4DMHeS4fli
■ Higti Lumriam f CHt BTVS^
■ <mV SmfMvleir ■ 2 ^ it iia Pttibtt
M VMt&gi, Tun*, » Fre^enc^ diPr»reiii:-Bj diS^llyid
4rt CRT Ihru trw UEfl of cursors (S- 1136^ Qnly)
■ Plui much, mucti hkha
DEliM SERIES
S-13^02SA#^JS4*« 5-1345 JOimzSSTS
B&K OSCILLOSCOPES
IZAKsMflcLlilKifi ondtcuit
[ Buih-fn Carrponcffl" Tit!
I Plui alt ;h# iaa.1ur» of in* "liordablv' senis
2120
2t2S .
2'eo
2C«Hi :;.d "-cie
ZauHt Dtiar^ Swmp,
ftOUHi Diitf Trscft. DiB^riKi Smtt^,
Duif Time Base t***
iQ'DMH'Z thri* Trace Dual TVn« Bet*.
Detayad Sweep SU70
- SOMH-i t' 20MS/S St^aoa iflW
Mull I meter
$175.00
taukmrtfaM
DtgitBl
Mul|lni«tir
S39.95
3*3,4 DiQi! UuHltne't^r
BK 390
$139.00
4 -t.OOO tbtft LCQ tiB^M^
Disltsl Capacitance
M«tir
CM^lSSS
$49.95
«S1l>Z3iQI||jC&(Hlb<l!
*** ^' :-.'ii;3ii5r
OlgiUi yultimeler KU
9f BwQ
Digital LCH Meier
LCH-sao
$79,95
« J t^ Dhfl'l LCD Diipl^i
1 hduHanCB %H 10 S3QH
* CvisiUfice ipl i»
Fr*(|UflrKy Counlflr
F-IKS
■'-r $225.00
Function Genera I or
$149.9S
smi wBvft
FLUKE MULTIMETERS
Mad*>f?
>iiod*i 10
li.2S.0Q
wos«T?e
FM Receiver Kil & Training Course
544. 95 AA2flGi»H
itrtr iriLdi^vt 4ta for ^tq^i^ipi
* OiJII CB^nrETlrgn 5i>pE^ti tisritvnE
AFZN5K MT
Bliirw Sotderi^g Eron
JSQIIP #7!
Tw5 lOQEI 1(1 aflfi riJ fit
10( hUBbv'^'Hl ms '.ttntiirj^n^
U HcfUEMF Prede
$63.95
Te1tpr1orhE^KIt
$14J5
iTrwirtjtof fMte Xits
Function Gan«rBtor
$29.95
Kfl S2«.»$
Tfiephcne Line Afsiiyier
«i.t^
KilTt-IBfR ITI^
Aj««UwdTP«M tMJS
Learn !o Build end Progrem
Compulers with thiis Kil
ini>aQcn
$129.00
V inv^ r« fan^o^ m 'Ml ^
Electronic Tool Kit
TKiOOO
Digital 'Analog Tracer
CDnnpi«ij Mi^i-Lab Fdr Buikdlng, ttfl4nO;
r^ioictrping knaioq tnHSlQlUlClrculli
$T59.95
Ki3 XK S25K
$129.95
a V ■» ^ I
VrE ■.'.'ta NOT Bt UNDERSOLD
PROG E 3 triCL A LL SC0f£5 A I^IETERS
C&S SALES INC
W5 ROSEWOOD QEEflFlElO.IL 60015
FAX4 7eft-S^0'C&aS * i7Da}$4l-OT1D
15 DAV MONE^ &ACK GUA«ANIEE
fULL fACIORY WARRANTY
Wl^llE FOR FREE CATALO&
w
here's the Beam?
Uncbiruiive DX Gain AnfE^nna& foc^ rbni 10
* Eiiily hid^ks * Ttistsll Fail • Fijc«j ar P^»ftable *
Tbcn'l 1 W Btdcir ulHBi «ili ml DX Wma^
MAAtm m Ai* pi^^mrc. V^ cie'i Mt lL aaJ ^,f>er
nd|jlN>n cu't flfbccSvi fl Mk«ii DX t^i^f-v:
i3rj.-«iy. Hew ibcm ft lo* pivTile 30 4Cn .Kt tn -
M»4*i7 Ori 2 «icac« s^va .+ laHt f.M l^ ink-?
Ail fnihr f]! ik< fwcttitioot fru-fj S^iS w %'^^
tWrti DX Hitfa-Dul t«IJi«|t lb* ■*tf;ll1>fm
Lflfjpi^si An ten na Selves t
sm^Krt^v.-,VJM&£:& fSQT) .173-8425
CIRCLE 332 ON READEFI SERVICE CARD
Say You Saw It In
73 Amateur Radio Today
^^ Fox Hunt Attenuator ^
^r^ T/^ '- *. 10 A i/DB- iaim 7u-» M^\ ^f^
w A -m ^ -m -M %*
4 «
a a
BBS
HMI
n • • • • a /^
Arruw Antenna
1*1 PfeaccxJt Fl t^oBos^ uW)66:i-54S5
Lnveland, CO mS^l l^m (3(B 663-5065
CtRCLE 80 OM READER SERVICE CARD
CABLE T.V. CONVERTERS
Jerroid"*. Oak. Scientific Atlantic. Zenith, &
many others. New' MIS stereo addon:
mute & volunie Ideal for 400 & 450 owners
1-800-826-7623
B&BINC. ^
3584 Kennebec, Eagan MN 55122
CIRCLE 21 ON READER SERVICE CARD
^'DESIGNING A YAGI HAS
NEVER BEEN SO EASYI"
. . . 73 Amateur Radio Today, Aprit "94
CIRCLE 104 ON REAPER SERVICE CARD
39
SI
rij*ri4m
mj ■ Mil HI4 -HCk im» «3iD *:n.* ^ui 41? nfl* «)
— - — t !■■ : I »i» ^^
?SWR
LH
m
It?
P7-.
1<|J
L2JJ
1J?I
IJ5I
IX I
nil
LJ1 I
UDl
IMl
l»i
Ull
l»t
lUX
1X1
(Pi
LJtl
This high speed, fliasy-to-use yagi software features auto-
d^sign. auto- optimise and performance analysis tt will
accurately calculate yp to 17 elements to 1 Ghz, with
boom and tapered element compensatNuns a folded
dipole option, and pnr*t5. a-'ii files, charts «nd graphs,
l/tdude^ bodi co-processof & n>Q co-piDcesscsr versions
f^ PC * Af w/MO K lUM, VGA. EGA. OaA Hvc aid DOS » v !
HOT£ NEW VERSION
Quickyagi -ao
AcldS3D0«A^0f fSOO^non-USAonivK • kid
Sflno SASE tor C(>T*fe -rtfo • US CheC* Or trnvrnfll I h^^iey enter
(602) 848-9755
450B N. 4aitl Of. PhO«niM. AZ fi50et
73 Amateur Radio Today * July» 1 994 71
Onaris fose parts like bolls, nuts, muf-
flers and pilots. As long as they Keep
on vlbraling on tfieir wooden crate-
cover basas, wtiile trying to mate with
the Honda nescl to them, mey tend to
ke^p on woridng.
Antennas: 15. 20- and 40m mono-
yagis: 10-15-2Q tnbanders, 12-17-30
tribander HF verticals, wire antennas,
and 70cm/2m yagis for saiellUe.
Radios: Nine Kenwood rigs of vari-
ous kinds (four died during the opera-
tion); four Alpha amps, which ran
beautifulJy without a hiccup. Various
satellite and RTTY gear was QRT up-
on arrival (rough handling) or went
QRT shortly thereafter
Cornpulers: For various reasons*
computers were only used tor RTTY»
and by one op for loggir>g. Atier five
days we were Eetl with on}y one work-
ing computer power supply, Most of
the logging was done on paper. Yes,
you can run RTTY pileups. even if the
only way to switch between trar^smit
and receive is t>y resetting ihe mo-
de in.
Luckily, all people Involved (hams
from the London area. Falklands, Pun-
ta Arena, locals from Fatklands, the
Antarctic bases and South America)
were very helpful; we were well pre-
pared (shelters, clothing, transporta-
tion) and had extensive Spare equip-
ment: we had the pilot stations (thank
you John ON4UN and Mark 0N4WW
fdr the super job as the European pi-
totst) to keep us linked to the DX com-
munity, to our homes, ar>d to all kinds
Of people involved in this operation
(trans portation. manufacturers, etc,).
Both of you pyt m so miich time, effort,
and quality in your tasks that it ia diffi-
cult to Ihank you enough; as opera-
tors, we were very motivated to bring
this challenge to a good end. I think it
was this motivation that got us
through.
It is really difficult to describe all of
the non radio stuff involved in such an
operation. Come to one of the upcom-
ing presentations and you wilt under-
stand. One thir^: We were not conv
plaining about the hardship we went
through. On the contrary, all o( us are
proud, y^Pi proud of wtiat we did.
p wish (hBt t could have printed the
complete report from Peter ONSTT ft
has a gerjutne humor that makes easy
fBading and makes certam humorous
pomts about the ftving corKittions en-
dured to bnrrg the rest of us amtacts
from one of the "rare ones. " Thank you
att for a job welt done! — Amie}
MONACO
Danlef Pfett 3A2LZ
8.R 349
MC 98007
Greetings to all from Monaco. This
has been a father quiet spring here In
the Principality — not too much unusual
going on. The Association des Radio-
Arrtateufs de Monaco had its annuaJ
meeting. The first order of business
was the election of the council tor this
year. Most of the council membeis re-
mained the same. The only change
was at Ihe positron of General Secre-
tary. Ciayde Passet 3A2LF, who has
worked hard at that position for a num-
ber of years. Is taking a year off.
Serge Safganik 3A2HM is filling the
position for this year
A number of projects are in the
works, Last year, some of the local
hams were asked at the last minute to
help the l^/lonaco Red Cross during the
Monaco Grand Prix. They apparently
liked the help and have asked us to
help again this year.
A foxhunt/direction- finding compeH*
tion is planned for June 1 9,
The Monaco repeater is about the
only repeater botuccn the Italian bor-
der and Nice. France. The mountains
further complicate VHF communica-
tions in Ihe area. The Monaco re*
peater has an unusual split though
which cannot be accommodated with
many 2 meter rigs. One of our projects
is to modify it to work on a normal
split.
There Is no further news on the 6
meter situation. 6 meter activity in
Monaco and the nearby part of Frarkce
is still prohibited.
Finally. iiYRL was fegafly active
from Monaco the beginning of April,
especially on 30 meters. Congratula-
tions if you worked fiim.
Let me remind you again that the
Monaco QSL bureau can only be used
for members of the A.R.M. We receive
a numtief of QSLs for nonmembers,
and this causes problems. And, the
onty correct address for the A R.M, Is
Box 2. Monaco- A number of other ad-
dresses appear in various DX publica-
tions but are inconect.
Best 73 from Monaco. Daniel
3A2LZ.
PHILIPPINES
Lorenzo a Gaston DU1CHD/6
P. O. Box 27
6116 Silay City
Neg. Occ.
Philippines
First, thanks (or the many letters
from the readers of this column, I en-
joy answering my mail but can't afford
to answer letters wiihoul an S.A,S.E. I
already have a lot of BURG QSLs to
answer for IOTA OC-129. and also
many direct cards without S.A.S.E.S,
which J have no choice but to return
via BUBO.
This month I decided to bring our
readers up to date with the additional
guidelines for the renewal of an ama-
teur radio license and application for
amateur radio examination.
I. Renewal of Licenses: 1) Before
an Amateur Radio License or Opera-
tor's PennH is renewed, the applicant
must show proof of his/her involve-
ment in amateur radio activities. An
Amateur Radio Ucer^e hokfer may be
involved in any of the following: a)
DX— He/she must tje abie to present
Log Extracts and/or QSL cards. DX
Awards earned as a result of hla^^er
DX activities; b) TechnicaJ Btpehmen-
tafion — He/she must show proof of be-
ing involved in the lachnlcal aspects of
the hobby, which may include propa-
gation tests and exploration, electronic
innovations (such as the improvement
of present equipment and acces-
sories), home-brewing of equipment
and accessories. These must be prop-
eriy documented with the submission
of test results, drawings and circuit di-
agrams where necessary; c) Emer-
gency Communications— He/she must
show proof of hkaving been involved in
purely Amateur Emergerx;y Communi-
cations and, in the case of an emer*
gency or disaster situation, participa-
tion ar>d active membership in tfie Anv
ateur Radio Emergency Service
(ARES) will suffice: d) Active member*
Ship in an Amateur Radio Clut>— An
amateur radio enthustast can only
grow and progress in his/her hobby
ttirough an exchange of ideas and the
support of his/her fellow amateurs.
Membership in an NTC recognized
Amateur Radio Club therefore is vital
and Important. This is optional but
highly encouraged; e) Field Expedi-
tion— This amateur activity is highly
encouraged lor radio amateurs, A
group can conduct a field expedition
by securing for a permit from the Com-
mission (NTC) and a corresponding
Special DX caiisign will be assigned
for the purpose.
2) The proof of Amateur activity wilt
come in a form to be submitted by the
appiicani with his/her application for
renewal (Form ARSCP-001). This
form must be endorsed by a local
club, duly recognized by the NTC as
an Amateur Radio Club or a Class "A*
Amateur Radio license holder, The ap-
plicant need not be a member of the
ciub where the endorsement was ob-
tained from, but the club or Class "A'
endorser shall be held responsible for
such endorsement of the applicant
IL Applicant for Amateur Radio Ex-
amination: 1) An applicant for the
Class "C" or "D* amaleur radio exami*
nation is required to attend an ohenta-
ten seminar conducted by an autho*
rized radio club or a Class "A' amateur
license holder with comesponding en-
dorsement E>efore ha^she is allowed to
take the corresponding examination;
2) The authority of an amateur club or
Class "A' amateur license holder to
hold seminars and endorse exami-
nees can only be Issued by the Ama-
teur Radio Consultative PaneL The
authority given to an amateur dub or a
Class "A" Amateur license holder shall
be for a period of one year only (re-
newable) unless sooner suspended,
canceled, or revoked for failure to
comply with the standards and agree-
ment set-forth by the Amateur Radio
ConsuHative Panel,
BAHERIES
NIckel-Cadmlumt Alkaline, Lithium,
Seaied Lead Acid For Radios, Computers,
Etc* And All Portable Equipment
YOU NEED BATTERIES?
WE'VE GOT BATTERIES!
CALL US FOR FREE CATALOG
E.H.Y0ST & CO.
7344 TETtVA RD.
SAUK CITY, Wl 53583
(608)643-3194
FAX 608-643-4439
Say You Saw It In
73 Amateur Radio Today
RACK BOXES NEW DEEPER SIZES
uocs.
«5
w^ajNim
iiiia«i.ii'
mn
mm
snta
91?
H.-^
DEsmwnoM
4tlFi3A
It as
PA
I
325
SESCOM, t^*C.
2100 WA^D Dfi MCM]Ef1SOI4. NV SgQI^ USA
USA/CANADA (^0} 634^^457 FAX laOO) 551-2743
OfFCE (702) ^6&'34in FAX (7Q2 j $S&'4e£8
Ti:a i LINE ' (702) 5^-3933 m--^ $ *tne. 4 j»m i¥m
CIRCLE 1 14 ON READER SERVICE CARO
1 HI l-f' ■^■^ ■*" ■—-■"-.—< J-^ .— ■ iL^ !■■
' -"'— — -1-^" ^"-1 —
CIRCLE 167QN HEADER SERVICE CARD
ONV SAFETY BELT CO.
P.O. Box 404 • Ramsey, NJ 07446
800-345-5634
Phones. FAX 201-327-2462
ONV Safety Belt WHh Seal Harness
*^// !l^ ' S89.9S
OSHA
We Shf fi
Worldwide
Order Oe$k Open
7 DayfiAVeek
ON V Tool Pouch $lS.dS
Add $4.00 For HandilngVlSAM/C CHECK
ONV Belt W/O Seat Harness
$74.95
CIRCLE 102 ON READER SERVICE CARD
72 73 Amateur Radio Today • July, 1 994
A
DVERTISERS
• A.aA , , ,70
• A.S.A 84
351 Absolute Value Systems. „....14
164 Ace Communications of
Indfianapoiis ...-....., .„.„..*.,,»41
• Advanced Elect ronic Applications ..9'
149 Advantage insirurnents
'Wjrpovo.iion ............. >^.^ ,.. », »i .1 »iHM« tttt » 1 J
231 Agreto Engineering _».„„ ...J©
194 Ail Electronics Corporation ....,,^.^3B
» Alphaiab... „ _.M
76 Amateur Networking Supply .,„..«., 17
• Ampire, Inc 14
1 1 3 Amsoft 53
336 Anlennss west f,,,.^.^.,,^^,*,^*,^ *r***^js
332 Antennas West «* 7t
107 Antennas West „ „„„.,73
363 Antennas West .83
132 Antennas West _„e4
296 Antennas West »,. ...BS
135 Antennas West 68
69 Antennas West 87
• Antique Radio Classified ..32
80 Arrow Antenna........,,, ., 71
t6 Astron Corporaiton,.,, 23
• Azden Corporation 43
21 BAB, Inc .,71
41 Barry Qectronics Corporation 21
»■- ■!■«>■■■■ ■■**'■#■■■«
42 BMl Oompan/
137 Sox Produces
56 Buckmasier Publishing
7 BucHmaster Publistiing
168 Suckmasier Publishing
• Bu rgtiardt A mat eu r Ha d i o
• Bulternul Electfonics
222 Byers Chassis Kits
■ ■ +-k + -t-l ■■ + + + ■■ I
PPP'P-i + FFIIi l + FPqq I I
.14
.54"
29
26
32
134 C 5; S Sates, fnc ...71
• CABLE X-PERTS. INC ..........14
239 Cam Lazercut Signs ., «,.. J6
• CB City internationaL.,.. .«»84
265 Chipswiteh , ,„,„,.8S
186 Coaxial Dynamics ,.........„....80
99 COfnmunlcalion Concepts. Inc 56
10 Communication Spedalists. Inc 65
356 Communications Oedronics, Ina .25
181 Digital Communicatjons 54
13 Doppter Systems ...,. „ «...6S
• Down East M icro wa ve . , . ., 64
114 E. H. Yosl 72
8 E[ktronics 65
• EUR-AM Efectronics 17
33 FB Enterprises ,,.,62
£31 rEyieuran ^....+^^».,,,,,.,,o/
118 FlyteCrafl .73
329 For Hams Only. _.....,..„... 32
• Gap Antenna Products . 83
193 GGTH
--- ■'«-<l--f<-P-P^ T^TTT^gB ■ ■< ■>*<-* Jfii-frHh i-ftbii I »->§•*■■-■
14*
338 GiObal Upgrades 85
230 Grove Enterprises ., .47
286 Hambrew Magazine „ .51
• Ham Radio & More 33
73 Hamsure » ...».» 32
• Hamtronics, Inc .„,„,7
345 Ham Windows... M
187 Harlan Technologies ^ 14
355 Harrington Software T7
87 High Sierra
B-ll'V-P"»1¥VVVI'>^b4i|BI>l1-VI-ll-l-V-F'«-l
,43
43 Highlands Electronics. „„ ....,.,53
293 \C Engineering.... , 32
179 icom,,.. CV2'
263 innotek, Ire.. 17
^'b' ■ k? V ^ I K/* I ■i-4^l-li^d--hl!liiFl l-lll4fl-lll-ri++llrii-l illl++FBil> + + + U^T
V-^ V V|J Wi t I .i. k |. L J H 4' h f ■ i d *+ F ■ 1 ^ + + -*- I i i +■>■ i i i I t't I I I + + 4' B I i1 ■■■I't'^ '
R.S.# page
228 Jade Products 85
133 Jade Products .49
240 Jan Crystals 26
159 Japan Radio , ...2
• K-Comm..... ............................. ...70
2 Kawa ProduclJons..„™ 32
151 KOC Sound... 87
• Kefwood USA Cofporatioo CV4
197 Lathrop Publicatioiis, Inc 66
234 Lentinj Communications.. 77
230 Maggiore Electronics Lab... „J6
• MCM Electronics , 60A
66 MFJ Enterprises.......... ,. 11
86 IVIFJ Enterprises .59
160 Micro Computer Concepts.... 53
144 Micro Control Specialities ... 81
114 Mr. Nicad , 72
243 MoTron Electronics „„ 31
223 National Anvaleur Racfio 86
54 HCG , ..» 5
1 t^lumber One Syslenis Ltd «., 68
• 0.F.3- Wealherfax ...........«86
102 ONV Safety Belt... 72
172 OptoeJectronEcs ..45
• PC. Electronics 62'
• PC. Etectronics ,.. ..63'
32 1 Patcomm 31
63 Periphex , .57
196 Persorel Computer Repeater
Controller.-,..... — , ..■,„..■■■ ...^.-Tl
• Personal Database — 51
249 Phillips InduStnes, Inc.. , X
3 1 1 P f oneer H il^ Sot tware , ... JST
49 Poly Phaser. ....69
257 Quorum Communications.,.. 27
153 Hadio City... ..,».i...i.3D
58 Radio Engineers ,..17
R-S-# page
• Radio Fun 73
' RAI Enterprises 71
34 Ramsey Eiectronics 19*
254 Ross Distributing............... ............85
• RT Systems ,. 17
• SAMS „ .17
36 Scrambftng News.... ...^
167 Sesoom, Inc. .72
...39
-^+-ft-l'fl-l I'VWFV'fl'l'
250 Software Systems ...67
244 Software Systems ....43
69 Spectrum Electronics ...,5f
183 Spectrum International....... .83
• Ten-Tec „. ,37
124 TeJtas Bug Catclier Antenna ..„.„. .87
• The Ham Center . . ..70
384 The Ham Contact ^^~. 78
384 The Ham Contact... ...57
269 Tigertronics ...............74
374 TNR 77
11 Transet Technologies 87
22 Tri-Ex 69
32 UniveTsat Electronics .56
• Universal Radio .70*
« Vanguard t-abs. 49
259 Versatel Commurtications 84
276 Virginia Beach Hamfe$L............74
104 Vis Study Guides. Inc .....28
191 W & W Assocates „. «75
20 Wolfe Communications ..„.83
• Yaesu Etectro nics Corporation . , ,CV3
268 Zero Surge. Inc ..,.<-. 49
Bold Listings are 73's J^w Advertisers Thlft Month.
^Advcnl^ers who \\avQ cantribuied to tllie Mallonai
Advisory ComrnilleC fMEACIi
J
0
UnobtrviJp^
- Eatily CdaoBsled
< So* PS ot% htr^hdd
' Wt^Qht only 1 ^oi
Add9 No Bulk or HcJoht
Range Exferxjer fof
2 metef Hand^iekls
' Boots S+gna' f"-3T Ft**
4 1 « AA-^ AraenrLM
* Improves ix3S% ftic*-i^*
*nd TfansmiT
■ 1^ai94S LOA' Pomvr
Pftriorrr.ence
Bait BooaM. ArBvo. ur 1^05^^300,936.7373
I ^^ See and Hear the Difterence
C1RCL£ 107 ON READER SERVICE CARO
The FLYTECRAFT'' SFX
Monoband Vertical I IF An ten no s
The ideal antennas where height and space
ure critical factors! Now Rated 1500 VV
and feskiiiring a new heavy -4uty metal bas«t
• 8 unique models Tor SO, 40,
30,20, 17, 15, I2^10meiers.
Each only 9 ti. t^tl (10 meter is
slightly shoneT.) • Predsioti-
wound fuQ length helii gives
excel lent performarKe.
* Unobinjsivc - perfect for
antenna-resiricted areas. •In*
st«iit set-up and tear down or
leave up permanently. # Top
wNp Adjusts for low SWR
point. • Use^ 2 shortened
luned radials wiiii fi^ytecraft"
jtADiAlxoiLs" (lOM uses 3.)
Buiti wrth pride & sold worldwkle -^ flyticraft* us a
S}^ m - $99.95 40, 30, 20. 17, IS. 12 - S^9M ea.
1&~S79.9S SfH Q*iUS"S7.50 (80. 40, 30M>;S6 y.i CJ^ .rAI ;
S«lis faction Ouinnlccd
visA/Mc phom: ordf:rs
800-456-1273
M-F 9A-5P (VT) IKkv 583-8173
Send CiJiccWS Order
LoL FLYIF-CRAIT"
P.O. Box 3141
Simi Valley
CA 93093
'*The beginner's guide to the exciting world of amateur radio."
Radio Ftm h packed full of informiition to
help you get more fun out of amaicur radio.
Basic ^how-to" articles: vvifl get you up and
running on packet, ATV, RTTY. DXing., and
ihe dozens of other activiiies ihai make
amateur radio such a great hobby. You'll get
equipment reviews geared toward the
newcomer- We'll help you upgrade to a
higher class license with monthly columns
designed to teach you what you need to know
in a fun and exciting way. You'll find il alL
and more, in the pages of Radio Fun.
Don*l wail another minute. Subscribe today for
only SI 2.97 for one year. Thai's 12 issues of
the only ham magazine that i.s geared especially
for the newcomer, or any ham who wanLs to get
more fun and excitement out of amaicur radio
— Radio Fun!
issues
for only
SI 2.97
1-800-
257-
2346
CIRCLE t18 CM READER SEHVlCE CARD
f
I
I
I
I
I
I
I
I
I
J
J
Q YES! Sign me up right nowl
12 fssties of Rddia Fun
for$12J7;
NAME
CALL
ADDRESS
CJTY
ChscK
hIC
STATE
Visa
ZIP
CARD*
QitSsUctinse
VearLcefis^
QSrSMti$Cfiljer
EXPIRES
73Subscr*jer
CO Sotjscrtoef
Mjiil lo: Radio Fmu P.O. Box 4926, Mfljicheisief. NH Q^IOS
fOr Call SOO- 257-2346 (in NH Call 625- 1 163 J. FAX:603-669^2K35|
Ciiividii fldd $7.00 plus .70 GST. foreign atW SlSOO surfaGe. $33 OO airmai
subocriptkm Rule £14-91^.
T
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
i
I
I
I
i
I
I
I
I
Newsstand Rate $ia.0O, Qnaio
I
73 Amateur Radio Today • July, 1994 73
Never Say Die
Continued from page 4
gram like this and I've missed ft,
please let me Know.
It allowed me to enter the monttiiy
sales figures for up to 10 years of
sales and would display them. Then I
could asit it to do a graph dt the Tigiires
and it would give me max and min
numbers and ask what max and min I
preferred for the graph. Once I typed
those In it would present the graph,
showing the sales for the 10 -year peri-
od. Okay, we probably have prograrrs
today that'll do that much. The r^exl
s^ was to ask it lo do a moving aver-
age of sales. ]t wouEd ask over what
period. Id leil it 12 months. It would
consider that for a minute and give me
a chart of the numbers. Then I'd graph
the moving average. These graphs and
charts could be easily printed, just by
hiuifig a key combinatimi.
Now we come to Ihe more vatuable
part, ft eouid calculate the second
deri>ratlve of the sales figures, showing
the acceleration or deceleration of
sales. I found that the number of pages
of ads tn 73 and in QST both had a cu-
rious 18- month sine curve that contin-
ued for years. Even more valuable was
the ability of the program lo project
sales into tlie future, based on trends
and taking into consideration periodic
changes, such as seasonal sales
changes. Is there anything out there
that can do this? I'll buy Itl
We're not talking Einstein here. The
math required fdr ali this is relatively
simple, ifs }ust that no one has both*
ered to buikj this irito a program for the
last 15 years. Phooey. Instead they've
been busy providing us with three-di-
mensional graphs and junk like that.
Hey, guys, keep it simple!
So what happened to Instant Soft-
ware? it was a good idea and it d(d
fairly welt, but when I sold my comput-
er magazines to IDG, they didn't want
to be bothered with mass-produced
software. And without the infrastructure
provided by the magazines, It coutdnl
continue. 6ut we learned a lot and had
tons of fun doing rL
For instance, we learned not to try
to sell educationai software to schools.
We wondered why some o( our prize -
winning stuff was selling so poorly.
When we studied oyr sales we found
that we were selling one copy to each
school and they were makJng all fur-
Iher needed copies. A couple years lat-
er we did ar>other study and found that
by [hen we were selling one copy to
each school district S talked with sev-
eral other software companies and
found they had the same experierce.
That's when educational software
stopped being produced. And that's
one reason we still don't have much of
it thafs any good.
At o<ir peak In tB^ we had around
a hundred people employed, were sup-
porting over 250 good programs, were
expanding rapidly into Europe and
considering opening an Irish plant.
Then IDG pufled the plug.
Let me know if you ever see a good
business analysis program for the
Mac.
Ahh, the Mac. I went out to Cuperti-
no for the unveiling of the original Mac.
There was tremendous hoopla^ but I
wasn't impressed. The IBM PC had
come on the market the year before
and it almost instaniiy wiped oul the
TRS'80 Up until I hen the microconv
pulef market was split with Radio
Shack having 40% of sales, Apple an-
other 40% (Apple II), and about 200
smaller companies sharing the other
20%. Old-timers will remember Com-
puPro. Morrow, Ohio Scientific. Mtd-
west Scientific, and a bur\ch more,
Apple was sami-lriendly to third-par-
ty supporting businesses, but Radio
Shack was hostile. Really hostile. So
when IBM came along, they had no
problem in capturing most of the third-
party support from Radio Shack, and
that quickly collapsed Radio Shack
sales. They went. In alKHJt one year,
from 40% ol the nnarket to atjoul 4%.
and have never really recovered. The
chairman. John Roach, never forgave
me for predicting that this would hap-
pen unless they changed their policy of
fighting third-party support. But did he
leam from this? Har-de-har. So Radio
Shack has beert a very minor player
ever since and Radio Shack lost bil-
lk>ns in potential sales. Tens of bitlions.
My view is that they could have pre-
vented the IBM putsch, if they hadnt
been so blinded by their own greed.
The Mac? It didn't really got any-
where unin desktop publishing came
along. The Mac has stayed a year of
two ahead of the PC in that field, and
that's been Us main strength. The Mac
PowerBook was a major step ahead
for writers like me. Td tried several PC-
type laptop computers, but none of
them were as easy to use as my old
Radio Shack TRS-eo Model 100,
which I thought Lhe day it came out in
1983, That went everywhere in the
world with me-
Last year i was about to start a
PowerBook magazine when I saw the
trouble coming for Apple as a result of
Scully's ego-fascination with the New-
ion. That got him frred. whidi was wen-
deserved, I thought But his rep^ce-
ment seemed weak, so I was afraid
that Apple would be rudderless. And
that's about the way things have tumed
out. My decision to not start the Power-
Book magazine last year has proven to
be prescient.
Souly. swept up in hts visions of the
information superhighway, jumped
without looking very carefully to anoth*
er firm, which turned oul to be built
mostly on vapor, which is a common
er^ough foundatian in the computer
field. So Scully is joining the parade of
has-beens in the field . . . like Jobs»
Tramiel, Busey (Tl). OeCastro (Data
General), Olson {DEC), and An Wang,
Oh, you probabty donl care about
all that okJ stuff anyway I just can'X help
remembering how interesting it was in
the early microcomputer days. I really
should write about them some time.
19bh Bnnual
Ua . Beach HamFesb
Ei Campuber Fair-
ARRL Roanoke Division Convention
Sept. 17 4 18. 1994
w Major Commercial E)(hibitors.
Deaiers S^Orgamzatnons
* Amateur Exarns & ijpgradas
^ DX & Technical Forunns
v Computief Hardware. Software
and Accessories
* Renty of Free Parking
* Held at Che Va. Beach Payi^on
* Talk in on 1^970
General Admission Tickets
$5 In Advance - $B At the Door
Tickets Good Both Daysf
HamFest Information Line
I 1-804-HAMFEST \
- Packet Radio -
Portable & Affordable!
Model BP-l
Pa eke I Modem
M&de in USA.
'A' Simple Instntlatioii
lA- No External Power
* Smart Dog^^ Timer
* Perfect For Portable
it Assembled & Tested
ifrVlfF,UHF,HF(im»
Tic Ice cs
Manny Stemer K400R
351 2 Qympia Lane
Va Beach. VA 23452
Exhibitor Information
Lewis Steingold W4BLD
1 006 Crabbers Cove Lane
VaBeaci^.VA 23452
Setid SASE' D«cis Pa^abte To THQ, inc.
CIRCLE 278 ON READER SERVICE CARD
74 73 Amateur Radio Today • July, 1 994
Whether you're an experienced packeleer or a newcomer wanting to
explore packei for lhe first time, this is what you've be^n waiting fof!
I1iank£ to a breaktlirough in digiiaJ signal proctssing, we have
developed a liny, full-feaiured. packet modem al an unprecedented
low price. The BayPac Model BP-l traasfomis your PC-compalible
computer into a powerful Packet TNC,
capable of supporting sophisticated features
like digipeaiing, file transfers, and remote
terminal access. NOW is the lime for YOU
iojoin lhe PACKET REVOLUTION!
4(K>D^|yLaae
P.O Bok5210
Grants Pas$, OR
97527
1-800-8BAYPAC
1 '800-822 9722
(SO3|47i6700 Jj
CIRCLE 269 ON READER SERVICE CARD
Cold Fusion VaMdationt
The Fopufar Science article Tast Au-
gust saying that cold fusion had been
given a premature buriaf by some pow-
erful vested interests almost got nie to
thinking. Like many others, I'd been
excited over the prospects cold fusion
offered wtien Pons and FleEschmann
announced the break-through 3n 1989.
Then the whole idea was trashed tjy
some vocal scientists, who were given
the usual extensive media coverage
providing bad news.
Then I read in the Rensselaer Re-
view that students had confirmed the
generation of excess heat as reported
by Pons and Fleischmann. This was
followed by two books bJastfng cold fu-
sion as a hoax. What in heck is going
on here?
Next I heard from a 73 reader who
was deeply involved in the cold fusion
field. He assured me that the effect
was quite real, despite the naysayers.
He started sending me information
confirming that researchers world-
wide had successfully duplicated the
early experiments and were busy de-
velopmg the technology. He convinced
me that there was a need for a maga-
zJne to hefp this new technoEogy grow
Ento an industry. It didn't take a lot of
convincing.
I'd seen the power of a magazine
when I decided to try and puti amateur
radio out of its deep decline following
the catastrophic ARRL reli censing ef-
fort in 1964^ when our growth went
from 11% per year to around a 3%
hi
PHV^iBIt le^SUE « WMk«SHJQEb«llW«rrv4ljyh
COLD FUSION
JS
a^rv^^mj ij
h:10;
MIL
III.. IW.HHa lll.l^ll
negative growth. We needed some-
tNng new to get the hobby going again
and 2 meter FM and repeaters seemed
like the ticket.
So I began publishing hundreds of
articles on the subject in 73. Then I
started the Repeater Bufletm, to further
push the technology. That was fol-
lowed by a series of books and re-
peater atlases. It was the Chicago
hams who developed the celiufar ap-
proach for their repeater system. Once
I saw that I knew that ft wouldn't be
long before this service would be made
available to the general public.
Within a couple of years we went
from having isolated repeaters put up
by pioneers to a nationwide network. J
foynd myself able to make repeater-
^:■i.'^5.;-¥■^ii^•f.:^^I■^
COLD
BISION
assisted phons calls while I was on
skis in Vermont, almost anywhere in
New Hampshire, and even from the ski
slopes In Aspen! Sure enough. GE and
Motorola grasped the significance of
what we*d developed and cellular tele-
phones were born.
Personal Computers
It was my success with repeaters
that got me to thinking about the criti-
cal importance of a pubil cation to help
new technologies develop into tndus-
trtes. The articles 1 published in TJand
the Repeater BuUelm had helped the
pioneers speed up their research by
providing the needed communications.
Further, my publications attracted the
interest of more pioneers and helped
bring them up to speed. And lastly,
they made it possible for entrepreneurs
to go into business supplying the pio-
neers, building an industry.
Within three years repeaters had
become the largest single interest in
amateur radio and built a $tOO-milllon
new ham industry. I particularly en-
joyed that because the first react bn of
the 73 readers was to complain bitterly
about my publishing so many repeater
articles. \ got hundreds of letters
threatening to cancel subscriptions if I
didn't cut It out. Then gradually I began
to get letters saying, hey, this stuff is
lun . . . thanks. At the time I was the
only ham publisher covering this new
technology, so I felt that 73 deserved
most of the credit for what resulted.
When, in January 1 975^ the first mi-
crocomputer was announced, I saw the
significance of the technology and de-
cided it was time to see if 1 could do it
again, I started trying to find an editor
who understood computers. For
months I chased after the editors of
computer hobbyist newsletters to see if
they might be interested in working
with me. Finally, in May, I found a chap
In Boston who had been publishing a
hobbyist newsletter with about 200 cir-
culation. He was game to give tt a try.
I set to work getting articles from
ham authors who'd been submitting
computer-oriented material to 73. I got
the names and addresses of anyone
who d ever written to the suppliers of
parts for computers. Some of them,
like Bill Godbout, had been advertising
FROM US, THE
--'^- ■■■■■■''
UtariilUHIikaUMIHII
MasterCharger® I & II
SPECIAL
FOR THE
MONTH OF JULY
MasterCharger®1 +1
BecErically fdentlcBf to MasfeefOiarger f
By simply changing adaptor cups, the
MasterCharger will charge any Yaesu,
Motorofa, I com, Kenwood, Alinco, etc.
2-Way Radio Battery
Replacement Batteries
KENWOOD
TH27/47 and
TH28/48/78
7.2V @ 800mAh
7.2V @ 1 SOOmAh
12V @ 800m Ah
LOOK FOR AUGUST'S
SPECIAL OF THE MONTH
MOMTHLY DISCOUNTS
APPLICABLE TO END-USERS ONLY
If you have two different radios
you'li only need one cliarger to
accomodate both radios. Now by
simply switching the switch to the
left or right, you can detemijne
which charging cup to activate.
NYS residents add 8.5%
s^fes tm, >\dd $4.00 for
postage and shipping.
wAmAssacMms
800 South Broadway, HickwiHe, NY 1 1 80 1
In US.A. & Canada CafI Toll Free 800-22!-0732
In NY State Call (5! 6} 942-001 1 « Fax (516) 942 1944
,; Worfd W^e DistHbutdrshipsAvaiiabie Please fhqurre '
MADE IN
THE USA.
FREE CATALOG
ANO Pi^iCi Ll^T
CIRCLE 191 ON READER SERVICE CARD
73 Amateur Radio Today 'July, 1994 75
quite successfully in 73, t got shoe
box 03 fill! of names from these com-
panies aad sent out subscription of-
fers. The response was incredible.
Most direct mail is considered a suc-
cess if one percent of the potential
customers buy. 1 was getting 20% I
The first issue of Byte came out in
August 1975 and looked pretty good
as a starter. The 73 editoriaU and pro-
duction staff had done most of the
work. It was lust five weeks from the
lime we'd decided to start Ihe maga-
zine until the first issue went on the
presses! I decided to visit the prospec-
tive advertisers personally, so I made
a trip to Albuquerque to talk with Ed
Roberts, who started it all with his
MITS 8800 Altalr microcomputer. I al-
so visited Sphere in Salt Lake City, a
computer game group in Phoenix, and
Southwest Tec hn real Products in San
Antonio, bringing copies of the first Is-
sue with me. I also stopped by to say
hello to my old friend Ed Juge, a 73
advertiser who owned a ham slore in
Fort Worth. I gave him a copy of Byie
and warned him that microcomputers
would turn Into a huge industry. Ed
had managed to survive the 'Incentive
Lk^ensirtg* holocaust, but by 1975 was
ready to give up trying to run his store.
Later 1 found that he'd gotten so ex-
cited over the magazine Td left tfiat he
bought an MITS Altair and hQ6 be*
come addicted. When Radio Shack
got into the business with their TRS-80
Model 1 In td?7. Ed got one and smart-
ed programming IL In fact, when I
went Into t^e business of selling soft*
ware in 1978, two of my first program
releases had been written by Ed. The
next thing I knew Ed was working for
Radio Shack. He's still there.
Between Syfe, Kilobaud, Microcom-
puUng. BO Mk^Q, Desktop Computing.
InCiden and a few of my other publica-
tions, plus dozens of booKs and hun-
dreds of software programs, the per-
sonal computer industry grew rapidly.
By 1 982 Byte was the largest con*
sumer magazrne m the country and
my 80 Micro was the third largest.
Vogue beat rt our for second place.
Compact Discs
When the compact disc was intro-
duced to America In 1982 1 decided
there was a need for a magazine to
help this new technology grow. I start-
ed work on this in 1983 and within a
couple years It had become the most
influential music magazine in the
country. CDs became the fastest grow-
ing consumer industry in history.
When Sony came out with Smm
video I tried to interest them in a sup-
porting magazine. J was unable to gel
any cooperation from Iham. They
didn't see the Importance and refused
to talk about it I wonder how big that
mdustry might be today if Sony hadn't
been run by marketing people with
btirxJers,
Cold Fusion
Considerrng the strength of the op-
ponents of co^d fusion, mosUy made
up of scientists getting billions of dol-
lars to try and develop hot fusion, and
rjghtfylly afraid that cold fusion might
drairi some research dollars . - * of
even put them out of bysiness . . . get*
ting a supporting magazine started
looked like an uphiiF Job. Worse, since
everything was stiti m the research
phase, there were few potential adver-
tisers.
As I kx>ked Into the situation I found
that while labs around the workj were
reporting success in generating unex^
plainable heat, no one had a theory
that explained what was being report-
ed. Researchers were empirically try<
ing this and that. They needed better
communications.
The prestige science magazines re-
fused to publish anything about the
field. Since what was being reported
was 'Impossible," therefore every sci-
entist involved had been making
stupid mistakes or else lying about
their data. This mindset controlled the
Department Of Energy (DOE), and
even the US Patent Office, where cold
fusion was classed as being as impos-
sible as perpetual motion.
Pons and Reischmann were so up*
set over ail this that they left the coun-
try. The Japanese quickly took advan-
tage of the situatiort, Toyota ap-
proached Pons and Fleischmann and
offered to set them up with a dream
laboratory on the Frer>ch Riviera . . .
where they are making great progress
with their research.
J decided to go ahead wtth a pubft-
cation. I announced It at the Fourth
Cold Fusion Conference on Maui in
December. My editor was Dr. Eugene
Maltove, the auttior of Fire From fee,
the only even-handed book on cold fu-
sion. At the conference I listened to
hundreds of papers reporting the
progress in the field arKJ had an oppor*
tunrty to meet the scientists involved.
Yes, including Pons and Fleischmann,
W was an exciting confer enca.
Upon returning to New Hampshire
we started working on iCo/cf Fusion"
magazine. We put the title in quotation
marks because no one yet has a good
theory of where the enormous
amounts of iieat being generated are
coming from. The first issue was
mailed in April, dated f^ay on the cov-
er. I didn't need any Jokes about it be-
ing an April Foot magazine.
Ln late March the BBC and CBC
(Canadian) broadcast welU researched
documentaries on cold fusion. They
gave time to the naysayers, but they
left no doubt that the phenomenon
was quite real and probably the most
important scientific discovery of the
century.
This was followed by the May issue
of MiTs Technology Review, which
had a cover feature on cold fusion,
complete with an tii)age article by Dr.
Ed Storms, who was our cover scien-
tist for the first issue of ICoW Fusion. '
so things were beginning to break.
Just to give you art idea of how posf*
tjve this article was. let me give some
quotes.
Manufacturers of Quality Communications Equipment
Repeaters
Remote Base
VHF, UHF
Receivers
Transmitters
» Antennas
Pro 'E'
EXPANDABLE REPEATER SYSTEM
•Standard and
Computerized
Controllers
•Standard and
Computerized
Auto Patches
•Duplexers
•A NEW CONCEPT IN REPEATER DESIGN, THE Hi Pro "E" IS AN EXPANDABLE REPEATER WITH THE
FOLLOWING FEATURES: A BASIC REPEATER WHICH WOULD INCLUDE A COMPLETE RECEIVER,
TRANSMITTER, COR. FRONT PANEL CONTROLS AND INDICATORS. LOCAL SPEAKER AND MiC JACK
AND CAPABLE OF FUTURE EXPANSION. ALL HOUSED IN AN EXTREMELY RUGGED, ENCLOSED,
19'INCH RACK MOUNT ABLE CABINET.
•THIS SYSTEM CAN BE EXPANDED AT TIME OF PURCHASE OR CAN BE AN ARERPURCHASE ADD ON,
THE ADD ONS ARE— HIGHER POWER, 110/220 VAC POWER SUPPLY, IDENTIFIER. AUTO PATCH, OR
COMPUTER CONTROLLERS. IN ADDITION TO THESE ADD ONS AN ADDITIONAL RECEIVER AND
TRANSMITTER CAN BE MOUNTED INTERNALLY FOR USE AS CONTROL LINKS, REMOTE BASE OR
DUAL BAND OPERATION, ETC.
• New 2 Year Warranty
NOW CELEBRATING OUR 25TH ANNIVERSARY
MAGGIORE ELECTRONIC LAB.
600 Westtown Rd. West Chester, PA 19382 Phone 610-43S-60S1 FAX 61M36-626a Telex 499 0741 WELCO
WRITE OR CALL FOR OUR COMPLETE CATALOG
CIIMJLE 130 ON READEf* SERVICE CARD
'v£*i%**i*^Aa^?miiM
Call S'gnt liter cut in miplti iBmlnata
wood, IJgN front wltli disrk rellgf,
• r Char's ori Vs" Base $2 per Characler
' 2" Char's on V/ Base $4 per Character
' 3" Char's on 1" Base S6 per Character
Shipping Included
CAM LAZERCUT SfGNS
P.0, BoTL 1090, Enfietd, CT 060^3-1090, 203-741-a4&5
CIRCLE 239 ON R&AO&H SERVICE CARD
Wayne is mad as hetl ...
...and he doesn't wantjati
to take it anvmore!
Declare War!
Ofi Our Lousy Government
Fed up with the mes in Washington?
The mess Id your state capital?
Fovcity, crime, our fajtlng sclvooh?
Wayne Green has solutions.
Oever solutions.
Wayn^ Green '£ unique neasonini; 1^ ininguing — tven
dclifhirul. Whciher you are honriricd by his proposals or
you cnibnice them, Lt h impoii^iblc lo ignore Uic b4t,sic lc?i-
^n he presents: It is lime lo bring bgk — no( crnmions
^ to bciLr on Americans dilemmas. Hl^ ttpin on America
in ihe 90*s helps us to understand how simple ihe seem-
ingly complex issues ure. All it takes h looking at ihem
from un eniircly new viewpoint.
Now uvailuble in one complete volume, Dec fare War!
i;^ full of thought provoking ideas und solutions to some
of the mosl, ditHcult problems fiicing our" Cftufltry ttxiay.
Regular price: $12.95
Special For 73 Readers
only ^ $10*00 fpi«*S?^«<ftlP|ibfAhaiidlb^'^
Order ToU-Free: 800-234-8458
76 73 Amateur Radio Todays July, 1994
"Some cord fusion experiments
have reportedly produced power den-
sities higher than those of uraniuf?t-lu-
eled lissfon reactors » , . Experiments
thai use cracK-free palladium and fol-
low the proper procedures now rou-
tinely produce heat, nuclear products,
or both . . , For cold fusion to occur,
the palladium probably must transform
No a ^}ecial condition of matter, akin
lo sijperconductrvity . . . None of ihe
proposed explanaiions for cold fusion
accounts for the full range of experi-
mental observations,"
My predictions of cold-fusion -pow-
ered cars with a sealed unit that would
provide power for years was being
backed up by Nobel-Laureate scien-
tists. Sure, the first products will be big
and expensive. You only have to visit
any science museum to see what ear-
ly steam engines and internal comt>us-
tion engines looked like, Bui as we
find out more about this power source
I believe we'lt have fuel-less planes
and $100 round trips to Africa. We'll
probably have micro- sized generators
powering wrisi communicators.
Shades of Dick Tracy! Our homes will
be heated and powered by units
smailer than a bread box. No more
need for oil. gasoltne, nalural gas,
coal, those big wind turlDines, or even
inefttcient solar power.
Free power? Just about. No more
gas slations or oil splits. No more coal
mining or well drilling. Welt, we need-
ed something. With the known re-
serves of fossil fuels already 50%
used up. the era of low-cost oil and
coal was coming to an end.
The Opportunity
With the deathblow to the naysay-
ers by the Technology Review article,
well start seeing some money going
into R&D here in the US. Japan is way
ahead of us in this field, so we've 3 lot
of catch-up to do. GonsideriDg the
head start Toyota has. Tm predicting
that perhaps as soon as the 1999
model year we may see a free-energy
Toyota announced.
We're going to see many more mil-
lionaires and billionaires as a result of
this new industry. And we're going to
see a mighty scramble by the power
and oil companies to cope with Iha
changes. The power companies
haven't been as impressed by the
naysayers as the government, so
they've been helping to fund some re-
search, I suspect they've a game plan
of reducing the cost of electricity with
this new technologyp and thus hoping
to stave off a massive move toward
home power units.
One outfit, EN ECO. has been work-
ing quietly lo get as much control of
the patent applications in the field as
possible. This cou*d pay off big for
them. Hie scientists involved need a
business organization to represent
their interests, and to help fund therr
continuing research, so it's a good
marriage.
With the publication of "Coia Fu-
sion,'the TV documentaries, and the
MU arlide, I think welt even see the
media beginning to lake a positive
look at what's been going on.
Yes. the chemistry and physics In*
vofved with cold fusion seem
formidable. But when you remember
that even the experts are unable to
explain what's happening, maybe
coming up to speed In this new lech-
nology isn't as impossible as self -de-
feated people alibi. When solid-state
electronics cam© afor>g in the 1950s
many of the old tube people gave up
and didnl even try to keep up. Tran-
sistors turned into ICs. which got ever
more complex. In an effort to build a
universal controller chip, Intel came
out with the 4004. This was upgraded
to the S008. the first 8-bit chip. Hobby-
ists took one look and decided they
could lurn this oonlroHer chtp into the
heart of a microcomputer by adding
appropriate software. That was the
beginnings of the microcompuler revo-
lution, intet upgraded to the S060 chip,
which Ed Roberts, a computer hobby-
ist, used as the heart of his Altair
8800. This product came just in lime
to save f^lTS- They had bet the farm
on sol^d- slate calculators, which they
were selling for S 130. Just as cak:ula-
tof prices dropped by about 90% Ed
announced the Altair and got over $5
million In orders rn 197&.
So t had lo start over and leam
how computers worked. It wasn't easy
at that time because there weren't any
textbooks worth a damn.
Now Tm teaming about palladium
loaded with hydrogen. Again there
are no textbooks to help. I'm learning
about nickel and hydrogen. aixJ so on.
And Tm not doing one single thing
that you couldn't do. if you had the
interest. I'm leamirg about deuterium,
tritium, neutrons, gamma rays, and
so on. It's exciting. I'm almost begin-
ning to understand the arcane lan-
guage of the scientists working willl
this sluff .
And like almost everything else IVe
tackJed, I've found that ft ^sn't a ques-
tion of brains, ifs just one of persever-
ance. Edison pointed out that genius
ES 99% perspiration and I have no rea-
son to question him on it.
Oh, Ft does help to keep an open
mind and absolutely refuse to ignore
anomalies. Pretty soon you find that
things Start fitttng together and making
sense.
No, no one yet fvas a good theory
for how the cold fusion effect works,
Bui then we don't have a theory we
agree on yet for electricity, gravity and
even Inertia. Many scientists are going
back lo the concept of *'ether* as a
medium in which radio and tight
*waves" travel, if you read much, you'll
be reading about all that
As you get into all this yoult find
there are a mass of newsletters and
departments on CompuServe and the
Inlefnel dedicated to discussing these
ideas. What there isn't is any guide to
ail this. And don't ask me to volunteer
for that one . . . I've got my hands fulj
witli cold fusion.
fgt^ 1-800-666-0908 SS'S=^rI^"n?
ALINCO
NEW!
I ^^^~*^
ttJ-IKT
CH'131'
EU-^lT
DJ-SaOT
(IFl'-Bkir'
CALL FOR ALL AUNCO
iCOM
iVFwr
iC-wnAT
CALL FOR ALL tCOM
FT-fiflO
FT-Jlo
YAESU
NEW!
NEWI
FT-tIR
FT-2anO^EWr
n-s30
4PWf?' S^ ^
FT-glflO
CALL FOR ALL YAESU
RADIOS a ACCESSORfES
STANDARD
CHBA
CIOBA
MEW
C&T"1B
CALL FOR ALL STANDARD
A£A • ASTHOH * AZOEN • COMET
'CUSHCRAFT* DIAMOND
. KANTRONICS • MFJ - SANGEAtl
* SONY SHORTWAVE * DRAKE
GRUND1G *MANY1l/IORE.-
NEW EQUIPMENT PRICING AND ORDERS 1-800-666-0908 OUT OF STATE
TECHNICAL, USED GEAR, INFO 203-666-6227 24HR FAX 203-667-3561
ICOM BATTERY INSERTS
BP-3
BP-3
BP-5
BP^7
BP-a
BP-8
BP-22
BP-23
BP-24
S.4v
8.4v
I0.8v
13.2V
8.4V
S.4v
8.4v
8.4v
10.8V
270mah
40Dmah
eOOmah
eoOmah
SOOmah
1400mah
270mah
SOOmah
SOOmah
S14.00
$21.00
S20.00
$23,00
$19.00
$24.00
$21.00
$17.00
$19.00
KENWOOD BATTERY INSERTS
PB-21
PB-2400
PB-25/26
7.2V
9.6V
B.4v
20Ornah
SOOmah
eOOmah
$11,00
$1 9.00
$21.50
YAESU BATTERY INSERTS
LENTINI COMMUNICATIONS INC.
21 GARFIELD STREET. NEWINGTON, CT 06111
Hours: M-F 10-6,
SAT. 10-4
ti»^
C.O.D.s Same Day
)K Shipping
C1BCLE a34 OK READER SERVICE CARD
FNB-2
FNB-4/4A
FNB-10
FNB-12
10.av
12V
I2v
GOOmah
SOOmah
SOOmah
eOOmah
$19.95
$26.00
$15.00
$25.00
IWORE BATTERY INSERTS
Tempo S"^ Earty
Tempo S2M/5 Late
Standard BP-l
Ten-Tec BP-1
San-Tec #142#1 44 Tabs
Uniden Bearcat
Unidan Bearcat
Regency MTIOOO Tabs
' A^ &■ 00 Sr^ipvig
270mah
eOOmah
270mah
eOOmah
6D0nnah
eoomah
SDOmah
SOOmah
$19.00
$21.00
$21.00
$21.00
$15.00
$15.00
S19-D0
$15.00
FL mctoftti fldd7% Saim Tax
TNR The Battery Store
279 Douglas Ave., Suite 1112
Altamonte Springs, FL 32714
1-800-346-0601 FAX (407) 682-4469
CIRCLE 374 ON READER SERVICE CARD
73 Amateur Radio Today My. 1B94 77
'«i
MWTiber 25 on your Feedback card
^^ msTiDer zi3 on you
Special events
Ham Doings Around the World
JULY 4
HARRISBURGt PA A Hamfest will be
held toy the Harrisburg RAC, 8 AM-2 PM
(Set-up at 6 AM). Location: Bressler Picnic
Grounds. Contact Steve Gobat KA3PDQ,
f&OC an Tmii Hd, Eners PA 17319; (7t7)
JULYS-IO
GANDER, NF. CANADA The ARC of
Central Newfoundland (ARCON) will host
a Hamfest at Hoi el Gander. Flea Market,
Seminars, Banquet. Contact ARCON. P.O,
Box 281. Gander. NF, Canada AlV m§.
JULYS
SOUTH MILWAUKEE. Wl Tfw South Mil-
waukee ARC Inc. will l^ol^ its 25tli annua!
"SWAPFESr at the American Legion Posl
#434 grounds, at 9327 S. Shepard Ave.,
Oak Creek Wl Irom 7 AM-2 PM GDI TaJk-
in on 146,52 WA9TXB9 or phof^ (4t4}
762-3235.
JULY ^10
INDIANAPOLIS, In The mdianapolis
Ham^esl Assn. will host the ARRL Central
Div, Convention at the Marlon County Fair
Grounds. Flea Market. Exhibits. Foaims.
Banquet. T-Hunts. Contact tndmnapolis
HamfBSt Assfi., RO. Box U776, tndi-
mmpolfS IN 4^01. Tei. {3t 7) 251-4407.
JULY 10
BALTIhlORE, MD The Maryland Ham-
fest/Comp titer Fesi will be held at Tlmoni-
urn Fairgrounds on York Rd. Set-up 2 PM
Sat, July 9th. Tailgating area opens at 6
AM Sun.. July tOlh: buiCdmgs open at 8
AM. VE Exams will be given at 1 0 AM only.
PTB-regisl ration is required. Call Les Mc-
Ctum W3GXT, (410) 833-S667\c pre-iBg-
isler. Tatk'in will tm m 147.03 and 224.96
MHz Rptrs. For Hamtest info, call (410}
467-4634: or write BRATS Hamfest, P.O.
Box 5915, BaHimore MD 21208.
PITTSBURGH, PA The 9th a/inual Ham-
fest o( the North hlilis ARC wiU be held 3
AM^3 PM at NoflhlarKi Public Library. 300
Cumb^riaml Rd. Rea Market, Seminars.
Silent Key Estate Sale. Tatk*in on
147.69/.09. Contact Don Jackson N3LAZ,
915 Dale Ave., Bramofd Woods PA 15015.
TeL (412) 935^3343.
JULY 16
lAI^CASTER, PA A Computer aixf Em-
Ironies Show, sponsored by Red Rose Re-
pealer A^sn., will be held 9 AM-3 PM at
McCaskey H.S. Set-up at 7 AM. Talk-in on
1 47.015+. Vendors conlad LBfry Harman,
Box 1S2, Leola PA 17540. TeL (717} 656-
0129. Fax (717} €5&3474,
JULY 17
VAN WERT, OH The Van Wert County
Listings am tee of charge as space permits P^^se send us your Speciat Event
two months in advaryce of the issue you vifanf it to appear in. For examplB. if yau
want it to appear in the January issue, we shouid receive it by October 3t Provide
a clear, concise summary of the essentiat details about your Special Event Checii
Special Events Fife Area mi on our BBS (603^924-93431 for fistings that were
too late to get into publication.
Fairgrounds Commeiclal 8ldg. will be tie
location lor a Hamfesl sponsored by Van
Wart ARC (WSFY). Time: 8 AM-4 PM.
Talk-in on 146.850. VE Exams, pre-regis-
ttr by July 101 h: Contad Bob HIgt} KABfAF.
12B38 Tomiinson Rd., Rocktord OH
45862: Tei. (419) 79&57B3 (befon^ 5 P/ML
T-Hynt. Hamfest. For info, call: Bob
WD8LFY, (419) 238-1877, aim 5 PM.
JULY 24
QUEENS, NY The Hall Of Science ARC
Hamfest win be held at the New York Hall
of Science parking lot. Flushing Meadow
Paik, 47^)1 111th Si Doors open 9 AM.
Set4ip al 7:30 AM. Contact (at night oniy),
CtiBftas Becker WA2JM (516) $94-3955:
or Amie Smffman WB2yXB, (718} 343-
0J72. Tatk-in m 444 .200 WB2Z20/R, or
146.52 simplex.
STICKNEY, IL Hamfesl '94, sponsored by
the Dupage ARC, wiil be held at
Hawtt>orrve Race Course. 3500 South Ci-
cero Ave Flea MarlteL VE Exams and CW
leslfng 9 AM- 12 noon,. waJk-ins welcoaie.
Please have your orlgGrtaJ Itoense. a pholo
copy anif a photo ID. For labfe into, call
(708} 985-9256. For advance tickets^ send
SASE and a cheok payable to DARC to
Hamtest '94, 75 It Walnut Ave.,
WoodTi(^ tL 60517.
JULY 30
ASHEVtLLE. NC TTie 19lh amwa? West-
em Carolina Hamfest (ARRL sarnSioned)
wm be he«d e AM-4 PM al Haywood Coun-
ty Fair Grounds (near Wayne svi lie and
Lake Junaluska). For Dealer and Flea
Market info, contact Miriam Smith KB4C,
(704) 683-4251. Get general info from Oic*r
Cfitcheit KY2Y, (704) 299-7356. Ttckel
contact is Ftay Cra^jftiu WBIHGO, (704)
298-7289: Of mail an SASE to WCARS,
PO. Box 1468. Asheviile NC 2880Z
JULY 31
SUGAR GROVE, IL TT>e Fox River Radio
League will hold its annual Hamfest at
Waubonsae Comiruiwty CoHege, Route 47
at Harler Rd. Opeci to ihe pubric al 8 AM.
Set'Up Sal. July 30lh at 7 PM, and Sun.
July 31st. 6 AM-8 AM. VE Exams at 10
AM, Talk-in on 145.470 (-600). Contad Bil!
Schaben WA9AUW, (708) 2O3-4370: or
Mark Hougaard KB9FCC, (708) 979- 1 71 7.
AUG1
DOYI^STOWN, PA Tbe Wyndmoor AR
Repealer Club of Doylestown will meet at
tfw Doylestown Towrtship Skig, Communi-
ty Room on Wells Road, at 7:30 PM. Inter-
ested persons may call Bob Agans, (215)
348-7366. The Club features speakers and
videotapes on topics concerning amateur
racfio. and tt>e¥ get togethef to study for li-
cense tests, etc. They often schedule
weekend exajrsions to ham radio events
I
Serving the LORD
Since 1937
THE POWER STATION
The POWER STATION is a 12V x 6.5 AmpHr gel^eli
oattery complete with voltmeter, wall charger and a
cord for charging via automobiles. It will power most
HTs at 5 Watts for 2-4 weeks (depending upon how long-winded yoy
are). Also VHP, UHF, QRP, or HF mobiles such as the KENWOOD TS-50
(at SOW). There are no hidden costs, all you need is your mobile, HT
power cord or cigarette lighter adapter.
The POWER STATION provides 12V from a cigarette plug and has two
recessed terminals for hardwiring. A mini-phone jack with regulated 3V,
6V, or 9V output can be used separately for CD players, Walkmans, etc,
THE POWER STATION can be charged in an automobita in only 3 hours,
or in the home in 8 hours. The charger will automatically shut off when the
battery is completely charged, so you can charge It even when it has only
been slightly discharged, (unlike Ni-Cads that have memory). Our charg-
ing circuit uses voltage sensing circuitry, other brands are timed chargers
which always charge the battery a full cycle, this damages their battery
and shortens its' life if it only needs a partial charge. The POWER STATION
has a voltmeter that shows the exact state of charge of the battery, not
worthless idiot lights that tell you "YOUR BATTERY IS NOW DEAD." The
voltmeter can even be used to measure voltages of other sources.
To order, send check or money order for S49.95 +
S8.50 tor shipping, along with your shipping address
and telephone number to:
Joe Brancato
THE HAM CONTACT
P.O. Box 3624, Dept. 73
Long Beach, CA 90803.
CA Resfdems Add B im% Sales Tax. Alaska. HawaH. and GandJ«n
R^shJenis, please &end US. Money Order & $17. iO Shipping.
It yon wiati more inlormation please send a SASE to the above Address. For
COD ordDrs. call (310) 433-536Q, Ouiside of CA Orders Only can (@00) 9^3-
HAM4 an^ leave a message. De^i^r irtqufuBs inviteii.
aRCI^ 3S4 OH READER SERVICE CARD
7S 73 Amateur Radio Today • July, 1 994
AUG S*7
VERNON. SO, CANADA The 3rd annual
Sky High Hamfesl wtH be hdd by the Nofth
Oka/iagan RAC. at Silvef Siar Mt. Resort.
Bea MarkeL Dimer & Dance. HF Station.
More. Contact North Okansgan ARC, P.O.
Box 1706, Vernon BC V1J BC3, Canada.
For hotel reservations, calf h&0Q*663-
4431
AUG 6
tNDtANAPOLIS, IH The annual WA9SNT
Kamfesi will be befd at ITT Tecti, insl.
9511 Angola Q., from 8 AM-3 PM. Sel-up
at 6 AM. This event is sponsored by the
ITT Radro Club. Talk-in wi 145.25-. Con-
tact Dave Jotmsion K9HDQ, (317} 875-
VALPAHAISO. IN The Poder County
Hainfsst and CompLrter Show, sponsored
by the Porter County ARC in co-operation
with The Porter County Tourism Bureau,
will be held at Porter County Expo Center.
Doors open at B AM (set-up at 6 AM). VE
Exams 9 AM- 12 Noon Talk-in on
146.775/-6kc 131.8 PL and 146 520 Sim-
plex, Contact Rich N9Q10, (219) 7&2-
8701: or s^kJ SASE to PCARC HamFest,
PC Box t78Z Vai^mmso fN 46384'1782,
AUG 6-7
JACKSONVIU-E, FL The Greater Jack-
sonville Amateur Rarfio/Compulef
Show/ARRL Northern Rori<ia Section Con-
vention, will be held at Osbom Convention
Center in downtown Jacksonville. Flea
MarVei. Hours: 9 AM-S PM Sal: 9 AM-3
PM Sun. Set-up at 2 PM-6 PM Fri. and 7
AM-9 AM Sat VE EKams Sun. at 9 AM.
Contact Greater JacksonvUle Ham f est
Assn.^ P.O. Box 27033, Jacksonvitte PL
I Tel. (904) 350-9m.
AUG?
CROOKED LAKE. ANGOLA IN The An^
nuai Land ot Lakes Angola Hamfest. spon-
sored by the Lana ot Lakes ARC. wi be
held 6 AM-2 PM at Steuben County 4-H
Fairgrounds, comer o* 200 W & 200 H. VE
Exams tor all dasses. Talk-in on 147.180^
145.090 packet, 444.350 131.8 tone,
444. 900/. 100, 224,94, 53.050, Contact
Sharon Brown WD9DSP, 905 WPkwy. Dr.,
Pleasant Lake iN 45779. m (219) 475*
5&97.
MARSHFiELD, Wl Ihe Marshfield Area
ARS will hold Iheir 3fd annual Rcnic, in
WiWwood Park, beginning around 11 AM-
This is a PotluckySwaptest, Talk^in on
147,180, Contact Guy A. Boucher
KB9GPJ, W7 West Thtrd St.. Marshfi&fd
Wi 54449. T0L (715} 384-4323- PACK*
En:KB$GPJ ^ W$tHW.Wl.USANA.
NORTH TARBYTOWN, NY The WestCh^
ester Emergency Comm. Assn. (WECA)
will hold their "WECA Summerfest 1994*^ at
Westchester County Center, Junction ot
Rte 119 and Bronjt River Pkwy. Talk in on
l47.06/,66. Vendors. Forums, VE Exams,
and more. Contact Jeanne Ratfae^, ($U}
962*9666.
PEOTONE, IL The 60th annual Ham-
test/Computer Festival, sponsoreii by
Hamtesters Radio Club, tnc., wilt be held
at Will County Fairgrounds 6 AM-3 PM.
Rea Market. Set-up Sal. Aug. 6lh at 6 PM-
12 midnight. Talk-in on 146.52 simplex,
146.64 (-) (courtesy of STARS); 146,94 (-)
{courtesy ot KARS). For info, call (708)
535-AHAM. Get advance tickets (SASE
and check by July 20lh) from Dsvid F,
Braset NF9N, €933 W. HO SL, Worth IL
60482, let. (708) 448*0560.
SPECIAL EVENT STATIONS
JULY 3
RUSSIAVILLE, tN The KokOmo ARC wi
sponsor a Special Events Station honoring,
the SesquEcentenniat celebration of
Howard County. Operation will be on BO,
40. and 20 meters in the bottom 25 kHz of
the General class bands, and in the 15
and 10 meter Novice ctass bands. The sta-
tion wiJI be on the air at 1400 UTC and will
continue tor 12 hours. Please QSL
w/SASE to Dick Elliot N9iPA, PO. Box
128. Ri^siaviSe tN4$9m
JULY 4
COEBURN, VA The Lonesome Pine ARS
will operate 0^OZ-22O0Z to commemo-
rate Coebum's lOCfh Centenfual Celebra-
tion. Operation win be SSB in the General
phone portions of 10, 20, and 40 meters.
For a certificate, please send a 9* x 12'
SASE to the lonesome Pine ARS, RO^
Box 2955. Wise VA 24293,
JULY 4-5
PLEASANTON, CA Uvemiore ARK wllJ
(^rate N5F0O 1700Z Jiiy 4ih-0i00Z Ju-
ly 5tfi* to commemorate the Centennial An-
niversary ol the City of Pleasanton The
station will operate from the Alameda
County Fairgrounds. Frequencies: CW
7,125; p*ione 14.250 and 28 485. For a
QSL. send your QSL and SASE to OfOl
Ross WABPYH/AG, 7005 Corinth CL,
Dublin CA 94568,
WILLIAMSBURG, VA The Williamsburg
Area ARC will operate W4TMN 1200Z July
4t?i-01002 July 5th, to celebrate the 218th
Anniversary of the signing ol ttie Dedara-
lion of Independance. F^'equencies;
146.58. 28.350. 24.950. 21350. 18.150,
14 270. 7.270 and 3.870. For an unfolded
certificate, send OSL and a 9" x 12^ SASE
to Hershel KfBi$ KE4GWV. U5 Sand m
fid. mimm^Hsrg VA23i88.
JULY 4-10
AUSTIN. TX Amaiteurs affiliated with the
American Sunbathing Assn., the Naturtst
Soc., and the Federation of Canadian Na*
turists. will observe the 19th annual North
American Nude Awareness Celebration by
operating a Special Event Station near
14265. 21.365. and 28.465 W- QBM. For
a certiticate, please send QSL and a §* x
12" SASE to Bob Redootey KF5KE RO.
Box 2008 1Z Austin TX 78720.
JULY?
BUTLEDGE, GA Attanfa Chapter 49.
QCWA, wiil demonstrate arnateur radio on
HF/VHF starting at 2 PM-9 PM, EDSt in
supporj of Ihe National Kidney Foundation
of Georgia's annual "Camp Indepen-
dence/' for young transplant ellgibles at
Camp Twin Lakes. It allows young people
to see and participate in amateur radio
commumcations. Frequencies: 7250,
14250. and 21,250 +/• QRM. using
W4NZJ. Alt contacts welcomed and invito
ed. For a special oSL card, please send
your contact info and QSL card w/SASE to
Judson F Whathy W4NZJ. 2t56 Wrndsor
Dr., Snetivitle GA 3027&,
JULY 7-9
PITTSBURGH. PA Station WA3BAK wilt
be on the air Thurs., Fri., and Sat., July
7th-9lh, 09:00 to 23:00 hours, En conjunc-
tion with the 56th annual Soc. tor Preser-
vation and Encouragement of Barter Shop
Quartet Singing in America (SPEBSQSA)
Intem'l Convention. Frequencies: 20 me-
»*• Al
Don't miss an issue of
"Cold Fusion" Magazine
Big savings off the newsstand price.
If you want to get the latest information on this new science and industry , , . to know
what's happening with cold fusion in the world, in the government, in the labs . . . then,
you need to subscribe to ''Cold Fusion" Magazine today.
Each month ''Cold Fusion'^ will have articles on:
• Researcti breakthroughs and developments from all over the world.
• Inter\iews wiifi the movers and the shakers in the field.
• Information on doing your own experiments.
■ Markets and investment opportunities.
» WKat ihe media is saying about cold fusion,
• What Washington is saying and doing about cold fusion.
• How the experts think cold fusion will affect your future as this amazing new energy source comes on line.
"COLD FUSION"
««•
YES, Charge my credft card: J AM EX Q VISA j MC
Card i
□ $58.00 {U.S.) DS68.00(CAN) :J S82.00 (FOfeign Air)
»== Expires
Signature .
I wish to subscribe. Please start my subscription Immediately!
Name Company
Address City
Payment must be U.S. funds drawn on a U.S. bank.
Phone
State
Zip
Country
OR CALL 800-677-8838 (Ext 304) (U.S.A.) 603-924^0058 (Ext 304) (Outside U.S,A.)
RU SI 0^4" Magazine, 70 Route 202N, Pelertsorough, NH 03458
603-924-8613
CF73A
73 Amateur Radio Today • July, 1 994 79
ters ■ 14 235/245 MHz; 15 meters ■
21,300/320 MHz. 10 meters - 28.300/320
MHz; 2 ffietef^ - 146.610 -BOO kHz; 220
MHz band. 224.00 -1.60: 440 MHz baiKS,
440.000 -5 MHz. PackeL W3HID
e W3IXR,#SWPA.PA.IJSA.NA. Bob
Schiesinger is Afwhor Operator All OSOs
wii! be coflltrmed by a spedat commemo-
rative QSL card* courtesy oi Yaesu. USA
DSl carets ar@ available to WA3V3AK
SWL's who $end a SASE to Bamer Snop
Binger$, 4952 Esther Dr., San Jose CA
$5124 USA
JULY 9
EAST GREENWICH, Rl Ihe Bd^ ARC
will operate Kl NOG from 13002 to 18002,
to coindde witti the annual Yankee Tune
Up at the New England Wireless and
Steam Museum. Operation will be;
Phone — lower portion ot the 20 meter
General subtand: CW^Novice portion ot
the 40 meter band. For a certificate, send
QSL and SASE to Bob Hm NE1E, RO.
Box t68, 3 LOWSt CU Fiskevilte Rt 02823.
EASTON, PA The Delaware-Lehigh ARC
will operate W30K 12002-24002 from
the Canal FestlvaL Operation will be
on 3 96S. 7,265, 14.265. 21.366, and
2B.36S MHz. For a special QSL, send
QSL, Conlaet number, and SASE to
DOM? RD 4. Greysione Bidg.. Nazareth
PA 18064,
JULY 9-10
raomi, NY station KY27 wiU be opemt-
ed 12O0Z'210O2 each day from the Sp*rtl
of Central New York Hot Air Bafloon Festi-
val and Air Show at the Oswego County
Airport. Sponsor The Oswego AR Emer-
ger^cy Service. Operation will tie in the
middle of the General 80. 40, 20, 15 and
10 meter phone bands; the Novice portion
of 10 meters, and t47.75/,15 MHz For a
ceitiflcate. s^nd your QSL card and a large
SASE to Fred SwrntOr^^i KY2F. RO, Box
5^7, Oswego NY t3l2B.
St LOUIS, MO The Monsanto ARA wM
Operate WBOBBN from 1300 UTC'0300
lire (both days), to commemorate the St.
Loyts Gateway to the Gold 1994 Olympjc
Fesltval dosing. Operation will be in the
GenerBi portion ol 40, 20. and i5 meters,
the Movice portion of 10 meters. 147 36+.
224.98% and 443.55+. For a special OSL,
ptease send a 9' at 12' SASE tor an ufi-
folded OSL» or a legal siz^ SASE for a
folded QSL. to M.A.R4., PQ Bqx 1596.
Maryland Heights MO 63043.
JULY 21-30
EDMONTON, ALBERTA, CANADA The
Radio Amateur Educational Society will
operate VE6KDA during the annuai
Klondike Days Exposition. Frequencies:
1.870 when conditions permit, 3.750 0200
UTC*0500 UTC; 7.2000 2300 UTC-0200
UTC; U.165, 21,220. 28.300, and 14.050
(CW) when conditions permit. For a QSL,
send QSL and SASE to RAES. Ritchie
Postal Oomt Box 75038, Edmonton AB
T6E6K1, Canada.
JULY 2^-24
PEHANG, MALAYSIA The Malaysian AR
Transmitter Soc. will sponsor a CW Corv
test 00012 Sat. Jdy 23rd^23592 Sun. Ju(y
24th. as part of an invitation Jor hams to
visrt Malaysia and attend the "SEANET 94"
Convention in hJovember Operation wiH be
on 160, BO. 40. 20, 15, arxl 10 meters (no
WARC bands). The Contest call is 'CO
SEA." Contact Seanet Contesi Manager
1994, Eshes Razak 9M2FK, PC Box 13.
10700 Penang, Maiaysia.
STRATFORD, NY The Fuflon County
Mahlon Loom is Committee will operate
W2ZZJ fmm 13002-20002 on the Ger^raf
class phone portion of 40. 20^ and 15
melefs. arxf on the Novice 10 meter phone
band, to celebrate the 163th Anniversary
of the birth of Or, Mahlon Loomis,
the American wireless telegraphy pioneer.
For iterature m(^ a certificate, send OSL
contact number, and a #10 SASE 10
W2ZZJ, 5738 SmWY 29A, Stratford NY
t3470.
JULY 25-31
CANTON, OH The Canton ARC will oper-
ate W6AL to celebrate the Pro Football
Hall of Fame Greatest Weekend. Time:
14O0 UTC'020€ UTC Frequencies: SSB -
28.350, 24,950, 21.350, 18.150. 14.270,
7,270h and 3.670 MHz; CW ^ 2$,125,
24,910, 21.125, 18.080, 14.050, 10,120,
7.125. and 3.700 +/- QRM. There will also
be RTTY, Pacl<et, AMTOR, Salellite. 2-me-
ter and 6-meter FM/SSB. SWLs are wel-
come. For an unfolded certificate, send
your QSL witli contact number and a 9' k
12' SASE, with two units of first-class
postage. For a QSL or a folded certificate,
send your QSL with conlad # and a #10
{business size) SASE to Randy Phelps
KD8JN. 1226 Deiveme Ave, SW, Canton
QH447tO-1306.
JULY 30-31
DANBURY, CT The Candl0«OOd ARA
ai^d lis members will sponsor the 1994
Connecticut QSO Party from 20002 July
30^-20002 July 31st. with a rest period
D4002-12002 Get details from Frank Et-
2lerN8WJ<Q, (203)350-3523.
AUG 5-7
IIILWAUKEE, Wl Members of the Mil-
waultse ABES will operate Station VV9WK
to ceiebfBie ttw 4th annual 'Picnic Ham*
held at Menomonee ParK in Lannon Wl.
Operation wiB be in the Gerwral phone and
CW bands on 75, 40, 20. 15 aivJ 10 me-
lers. For a cerlificale, send OSL and a 9" at
12" ifivQlopt (wtth 2 tHitts of postage) to
WaWK c/o John Leekty 757 N Broadway,
SiMte 306, mwmikee Wt 5320Z
AUG 6-7
BWNEGAT UGHT, NJ The Old Barney
ARC wfti opemie W20B from "OLD BAR-
NEY," ihe Barnegat Lighthouse (Long
Beach Island IOTA NA-111). to coin-
memorate National Lightl^ouse Day. Time:
3000 UTG-OOOO UTC each day, Frequen-
des: Look in Itie lower 25 kHz of the Gen-
eral phone bands; 40, 20, 15, and 10 me-
ters, plus 146-52 simplex, 146.835 Rptr,
and other local Rptrs. For a special QSL,
send a 9" jc 12* SASE with 2 units of
postage f via NU2F. For more info, contact
QSl W20B v/a NU2f, Joe Retshlnger Sr.,
75 Joshi;a Or., ManAhawkm NJ QB050
USA
AUG 7-1 3
POTTS VILLE, PA The Schuylldl ARAn*
Operate N3ILC M^ Tlh-Aug I3th, to j^le-
brate the SchuyikJB Coun^ Fair Operation
wii be both CW and phone on the General
and Novice subbands. For a certificate,
send QSL and SASE !o Bd Brennan
N31LC, 520 Spnng Garden St., PattsvIKe
PA}790Ur651.
Measure Up With Coaxial Dynamics
Model 81000A RF Directional Wattmeter
Model 81000A is a thoroughly engineered, portabfe, insertiort type wattmeter
designed to nneasure both FWD/RFL
G. W. power in Gqaxial transmission lines.
61000A is comprised of a built-in line
section, direct reading 3-scal©
meter protected by a shock-prool
housing. Quick-match connectors,
plus a complete selection of plu§*tn
elements, gives the FRONT RUNNER
reliabihty. durability, flexibility
and adaptability with a two year
warranty.
Contact us for your nearest
authorized Coaxial Dynamics
representative or distributor in
our world-wide sales network.
COAXIAL
DYNAMICS,
INC.
15210 Industrial Parkway,
Cleveland, Ohio 44135
216^267-2233
1-800-COAXJAL
FAX: 21 6-267-31 42 See Us At Dayton « Booths 401 & 402
Service and Dependability, . A Part of Every Product
ClftCLE 186 ON READER SERVICE CAHQ
Random output
Continued from page 8$
got a big laugh around the office, stno© Tm 80
conservative I make Rush Limbaugh look like a
'New Dealer"). I also got accused ot being a fas-
cist One angry gent who didn't have the courage
to give his return address wrote to Wayne instead
of me and said I must be a new ham, since I didn't
know the first thing about radio or regulations, and
that I should not be allowed to write any more
columns (for the record. I've been licensed for 21
years). Go figure.
At the very teast, I expect the san^e respect
fmm you as 1 give. I do not write down lo you. nor
do I assume that you are all ignorant. I do no! ^m
how long youVe been a ham, rur do I assign any
prestige or instant authodiy to any partJcular class
of license. If you're going to bother to write to me.
please have a rittJe respect for yourself am/ me.
We can disagree. l>ut let's fem ember to use logic
to make our points, not insults
All I did was suggest that we give some
thought to why we fmd it necessary to carry
around radios capable ol transmitting on poHce
and other public sendee h'equencies. 1 wanted you
folks to mink alxiut it. If you feel threatened by
that, then I suggest you probably need to do a lot
more self-examination on this Issue than the rest
of us.
As always, I appreciate every single letter that
comes in. I don't care if you agree with my opinion
as long as you actually have one. Having an opin-
ion means more than just a knee-jerk reaction to
something that offends or threatens your belief
systems, it means taking all of the available input
and fomiing your own ideas. It's not difficult arKl
ygu don't have to be a college graduate to do it.
but it does take effort. Mental effort.
&0 73 Amateur Radio Today • Jufy. 1 994
■^^ Number 26 on )
Barter w buy
your Feedback card
Turn ycyr old ham ancf computer gear rnto cash now. Sure, you can wait for a hamfest
to try and dump ji, but you know you'fl get a far mors realistic price if you have it out where
100.000 active ham potential buyers can see it than the few hundred local hams who come
by a flea market table. Check your attic, garage, ceilar and closet shelves and get cash for
your ham and computer gear before it's too old to sell. You know you're not going to use it
again, so why leave it for your widow to throw out? That stuff isn't getting any youngerl
The 73 Flea Market, Barter 'n' Buy, costs you peanuts (aimostj^comes to 35 cents a
word for individual (noncommercial) ads and $^.00 a wofd for commercial ads. Don't plan
on telling a long story. Use abbreviations, cram rt in. But be honest There are plenty of
hams who love to fix things, so if it doesn't work, say so.
Make your list, count the words, including your call., address and phone number. Include
a check or your credit card number and expiration. If you're placing a commercial ad, in-
clude aa additional phone number separate from your ad.
This is a monthly magazine, not a daily newspaper, so figure a couple months before
the action starts; then be pre pared ► If you get too many cails, you priced it low, If you don't
get many caKs, too higii.
So get busy. BEow the dust off, check everythcng out, make sure it still works fight and
funebe yoo can help make a ham sure it still works right and junefae you can help make a
ham newcomer or retired old timer happy with that rig you're not usirQ now, Or you might
get busy on your computer and put together a list of smaii gear/parts to send to those inter-
ested?
Send your ads and payment to the Barter 'r' Suy, Judy Walker, 70 Rt, 202 N, Peterbor-
ough NH 0S45a and get set for the phone calls.
The deadline lor the August classi-
fied ad section is June 9, 1394.
ALL ABOLFT CRYSTAL SETS. Tiieo^
ry and constructton of crystal set ra-
dios. $9,95 each, ppd USA. Send to:
ALLABOUT BOOKS. Dept, S. P.O.
Box 22366, San Diego CA 921 92.
BNB200
CUSTOM MADE-HAND TOOLED
leather products with your initials,
name, call ietters. Photo's & estimates
available. Key rings, wallets, belts,
purses, hanging signs, specialty items.
GREAT GIFT. LEATHER & WEST, 67
Causeway Rd.. West Swanzey NH
03469. (603)352'6256- 9-4 pm. M-F
ET BNB215
SELL; NOG 15m QRP transceiver,
used ittle, A1 condition, $200,00. av.
Couch, 2029 JoAnn, Newton KS
67114. BNB220
QSL SAMPLES- 50 cents. SAM-
CARDS, 48 Monte Carlo Dr., Pitts-
burgh PA 15239. BNB275
ATTENTION HAMS! Subscribe to 6-
50 Worldwide for Six Meter Enthust-
astSt OX Digest for DX Chasers, or
The Novice/Tech Report. Call
(817)694^4047 or FAX (817)694-2522.
Br^B292
COMMODORE 64 REPAIR, Fast turn
around. SOUTHERN TECHNOLGIES
AMATEUR RADIO, 10715 SW 190th
Street #9. Miami FL 33157, (305)238-
3327. BHB29S
KIT BUJLDERS^Announcing a NEW.
SYNTHESIZED qrp Transmitter/
Transceiver, the ARK4. Get on the afr
for only $99.95f {Transmitter Kit only)
Buy as little or as much as you want
Full Transceiver Kit w/case only
$199.95. One board, no wiring, top
quality components & PCB. GUARAN-
TEED TO WORK. For Info send
SASE; Call/Write 10 order: S & S EN-
GINEERING, 14102 Brown Road.
Smithsburg MD 217S3; (301)416-
0661 . BNB304
WANTED: Electron Tubes, ICS, Semi-
conductors. ASTRAL, P.O. Box
707ST, Linden NJ 07036. Call
{800)666-8467. BNB307
KENWOOD AUTHORIZED REPAIR,
Also ICOM, Yaesu. GROTON ELEC^
TRONICS, Box 379, Qroton MA
01450. (508)448-3322. BNB310
RCI-2950 OWNERS: New modifica-
tion manual including Power increase.
Clarifier modification. Modulation in-
crease. Operating hints, and more-
Parts included. Only S20.00 ppd in
U-S^ (Missouri residents add $1.15
tax). SCOTT, P.O. Sox 510408, St.,
Louis MO 63151-0403. (314)846-
0252. Money Orders or COD.
8NB340
HR2510, RCI2950, CONNEX 3300,
COBRA 148, GALAXY SATURN, plus
many more kits to increase your mod-
ulation, $19.95. (800)536-0109.
B.NB350
KIT BUILDIRSI Complete itst of 165+
kit vendors. #10 SASE 4- $3.00 USD
to; RUTENBEB ENGINEERING,
38045 10th St. E. #H75-AR, Palmdaie
CA 93550. BNB365
QSL CARDS — Standard and cus-
tom. Your ideas or ours. Excellent
quality Foil stamping avail alDle, Many
designs and type styles. Catalog and
samples $1,00 refundable. WILKINS,
Dept. A, Box 787, Atascadero CA
9342a BNB370
MANUALS KW940 Owner and Shop
manual with schematic, $20.00; also
Heathkit SB220-1 manual and
schematic, $20.00; also NEW 3-500Z,
$85.00. (21 0)435-6190. BIMB381
NEW NN1G CW SUPER-'HET SIN-
GLE BAND TRANSCEIVER KIT.
Available in 20M, 30M, 40M, 80M.
$59.95 plus $3.75 S/H. (Catalog-2
Stamps). DAN'S SMALL PARTS &
KITS, 1935 South 3rd West #1, IVIis-
soulaMT59S0l. BNB385
Continued on page 83
l^itdjgl^tfteldS^
i
-%
4 ■ J. q. II H
»t^f j^-,-!^:_j^ "*" ■■*'' * ' I » b- * ■ -h l>
t J ■ h 4 P P ■ l-.'^L ^ i -r w ta
h 4 I- + 4
^*X■=- ----
I •■. ■ 1. ■ i'j i I
This' is 0 n .Of^Qubi f.iri^Bf Pri nt ;f:eiptU red. tiyiitihe' TiIPt.], .
versus time s£6rt-up thorQcteristic-even radios of the
some fYiQ lie and modelJ; This ^FjfigerPrirtt^ <bn ;be
captured;^-: stored <:ind andtyzed. Our e^ IxlD
SofttuQfei and 'the potent^ the TxID-l^
ISIW/CompoUbife circuit bobird ^dn help vod ideritif^^
the abusers Oft your repeateri Or help you keep tracfi
oF the number or radios per Qccdunt on commerciol
repeoterspO decoding^ os uuell ds
Spectrtim OccupdhGy bnd Devidtlorii - meosuremeni
lectures farther enhance the si/stem*^^
.,^:y::#'^Xall or:UJ^ fijllidetorts^;?^
|Til||;^1 tt
. Vteo^^ Qod F!M€X oe<epced . COD em ^sh or Mone^i Order bosl^i bjrily ^i::.::: ^
^£^'' ^0^^^'' Gcwemirtiettt f%ehci£© Orders occeptiftd: vxliiiv" .:iM^'
,0i- oixleis: (800) 338-9050-*^^'^'*''' -~^""
lofo-tSOS) 65?-S1 f 6 Fax: (503) 66t-Sl492
. "■: X'^^ ■
t'M'rv!''"'
■:*"'■-■
.■.■>m
CIRCLE 248 PN READER SERVICE CARD
PERFORMANCE
AND VALUE
WITHOUT COMPROMISE
KRP-5000
REPEATER
2 METERS-220440
Word lis spreading fast-
"Nothing matehet Ih9 KRP-5000
fbr total performance and vilu#. Not GE« not •v*n Motorola.
RF performance really counlss Fn|f»y hipri Derformanc^ op
I' Jigh re.pealt \/[ron- i .uamm
■ 1 1
au
1 1
VI (fi
prog ram ma
^^ufse r
ages
KtF 5000 Repeater shown
w^th PA100 Amplifier
call or wrfte for the full
performance story . and
tne super value price!
Micro Control SpeciaUies
23 Om Park. Grove^ajuj. MA 01S34
(508)372-3442
FAX (50S}3T3-73Q^
The first choice in
Transmitters - Receivers
Repeaters
Repeater Controllers
Power Amplifiers
Voice Mail Systems
CIRCLE 144 ON READElt SERVtCE CARD
73 Amateur Radio Today • July, 1 994 81
New products
Number 27 on your Feedback carrf
Com pi fed by Charles Warrington WAIRZW
HAMTRONICS
Hamtronics has announced the
new COR-6 module — a voice ID re-
peater CO rtrolEer combining COR cir-
cuits and a real-voice ID on one
board. I! can be used with transmitter
and receiver modules Ip iTiake ^ sim-
ple, low-cost repeater
A digital IC records up to 20 sec-
onds of your voice, using audio from
the repeater receiver The un(t in-
clucies tail and lime-oul timers, cour-
tesy beep, and a soiid-stale relay to
key the transmitter,
The kit price is $99; or the unit is
available wired and tested for $149. A
catalog is aiso availabie. For more in-
formation contact Hamtronics, Inc.,
65-F Mout Rd., Hiiton, NY U4S3-
9535: (716) 392^9430, FAX (718) 392*
9420. Or circle Reader Ser./[ce No.
202.
B+K PRECISION
B+K has introduced their first digital
mufti meter that is truiy pocket-sized —
the instrument is only 4.4 " x 2.2" x 0.4'
and weighs only 3.5 ounces with bat-
teries. The Model 2700 DMM mea-
sures AC and DC volts and resistance,
wtth data hold, range hold, audtbfe
continuity lest, diode test, bar graph,
and 3200 coy nt LCD display.
Data hold freezes the display to
hold a reading. Range hold allows the
user to defeat autoranging and select
one specific voltage or resistance
range for ail measurements. This is the
only pocket DMIVI to olTer ail these fea-
tures.
For more information, visit your fa-
vorite dealer or cont^t Bi-K Precision,
6470 W. Courtfand St, Chicago, ii
60635; (312) 889-1448, FAX (312)
794-9740. Or Circle Reader Service
No. 204.
SINCLAIR RADIO LABS
Sinclair Radto Labs has introduced
Bn intelligent site monitor for remote RF
transmitters and associated antenna
equipment The AMV-6A measures RF
power from 1 to 990 watts in both the
fonrt/ard and reflected mode simultane-
ously, allowing for easy VSWR calcula-
tions.
Near Intuitive setup and program-
itiing make this power monitor simple to
use, and no computer or other ancillary
equipment is required for irtstailation.
The unit allows system power and
VSWR tests without disconnecting coax
lines.
For more informalion contact Sinctair
Radio Laboratories, inc., 675 Ensminger
Rd, Tonawanda, NY 74150; (716) 874-
3682, (BOO) 288-2763, FAX (716) 874-
3682. Or circle Reader service No. 206.
PACIFIC SCIENTIFIC
The same commercial duty reliabiti-
ly found In Redi-Llne mobile electric
generators Is now available in an elec-
tronic inverter to meet your portable
power needs. The Hedi-Line model
DA1 21-24000 solid-state inverter op-
erates from 12 VDC vehicle batteries
to run 120 VAC, 60 Hz equipment
wherever commercial power is not
conveniently available.
The new Redl-Line inverter will op-
erate sensitive electronic equipment
requiring a regulated output, including
personal computers, and Is ideal for
equipment requiring up to 2000 watts
(continuous), 2400 watts (for up to 15
minutes), and surge output of up to
5900 wafts, for loads like heavy-duty
power tools with high starting currents.
Power conversion efficiency is be-
tween 85-93%.
A brochure with specifications and
other practical Information is available
for $4 to cover shipping and handling.
For more information contact Pacific
Scientific, inquiry Handling Depart-
ment 1084 Oid Colony Road, Laite
Forest, IL 60045; (815) 226-3100, FAX
(815) 226-3080. Or circle Reader Ser-
vice No. 201 .
TIARE PUBLICATIONS
Work the world with 1 watt! Make
contacts of over a thousand miles us-
ing just milliwatts! Thafs just a sample
of the fascinating fun you can have
with the new book Low Power Commu-
nications - Votume 2 - Advanced QRP
Operating.
Conceived, coordinated, and edited
by Richard H. Arland K7YHA. the
book's eight chapters were written by
some well-known QRPers, including
73*s own Mike Bryce WB8VGE. Chap-
ters cover; QRP DXing» contesting,
satellites, antennas, solar power, mi-
cro- and ml Hi -watting, and DXpedition-
ing on a QRP
budgeL
The book is
illustrated, and
is priced at
$19.95. (t is
available from
your favorite
dealer, or order
direct from Tiare
(add $2 USA, $3 elsewhere for S & H).
For more information contact Tiare
Pubiications. P.O. Box 493. Lat<e
Geneva, Wi 53147; (800) 420-0579,
(414) 248-4845. Or circle Reader Ser-
vice No. 203.
KANGAROO TABOR
SOFTWARE
Kangaroo Tabor Software has an-
nounced the new CARMAN 2.0 com-
puter-assisted prediction manger. This
is a professional-quality ION CAP pack-
age that allows anyone to use the most
advanced propagation routine interfac-
ing with the ELNEC and MINI NEC an-
tenna analysis gatn patterns.
CAPMAfsl is the versatile menu-driv-
en skyway analysis package devel-
oped by Kangaroo Tabor Software and
the prime author of lONCAP. CAPMAM
delivers lONCAP input file constnjction
and management^ two integrated exe-
cute functions: the ability to view and
manipulate huge output files, and
graph teal display of output parameters
for multiple target locations and time
periods.
This product contains a full-featured
location database and can be easily
customized. The CARMAN package
requires a 386 or better PC or compati-
ble. The lONCAP program Is included
in the CARMAN package^ which is
priced at $89 ppd. in the USA (else-
where add $3.50 S ^ H). For more in-
formation contact LUCAS Radio/Kan-
garooTabor Software, 2900 Vaimont
Hd., Suite H, Boutder, CO 80301; (303)
494-4647, FAX (303) 494-0937. Or Cir-
cle Reader service No. 205.
Aclypse Corporation has an-
nounced the ADR-1 Robot Kit, a little
something different for the ham who
has everything. The robot is 27" tall x
14" in diameter and weighs 16
pounds. The complete kit has an on-
board computer system that features
voice recognition capabilities. English
ACLYPSE CORPORATION
speech output, power motor drive, and
a battery with monitoring and recharge
system.
No electronics or advanced com-
puter experience Is required. Con-
struction takes two to six hours and
requires no special tools. The robot
has its own operating system and
a BASIC programming language is
built in. The complete kit Is priced at
$299.
For more Information contact
Aciypse Corporation, RL 2. Box213H,
Worthington. iN 47471; (812) 875-
2852, BBS (312) 875-2836. Or circle
Reader Service No. 207.
82 73 Amateur Radio Today* July, 1 994
^ *i « *
Barter 'n' buy
Cofitinued from page 81
SERVICE MOMTORS WANTED
SERVICE MONITORS . , . - . WANTED
Any tate mode) Test Equipment.
CaJI. {408)241-7376. BNB390
irS BACK! The return of the HW-8 Haudbookl
Second printing. Modifications for the Healfi QRP
rigs. First diass maii $11. DX add $4 for air mail
shipping. Mike Bryce, WBBVGE, 2225 Mayflower
IMW. Massillon OH 44647. BNS404
MAHLON Looms, INVENTOR OF RADIO;
(patented 1872) by Thomas Appleby. (Copyrighl
1967). Available from JOHAN K,V. SVANHOLM,
N3RFt SVANHOLM RESEARCH LABORA-
TORIES, RO. Box 81, Washingion DC 20044.
pjease semi $25.00 donation with S5.00 for S&H.
BNB420
BROWNIES QSL CARDS SINCE 1939. Catalog &
samples $1 (fefundable with order). 3035 Lehigh
Street, Allentown PA 1 81 03. BNB430
QSL CARDSIll Customize one of 26 standard
formats, or create your own design. FREE info-
packet (75 cent stamp appreciated). CHESTER
QSL's, Dept. A, 2 South Commercial, Emporia KS
66801. (316)342-^792, FAX (316)342-4705.
BNB434
BUTTERNUT ANTENNAS. NEW— in box. C2)HF6-
VX, $125.00: (2)HF5B, $200 00; {2}HF2V. $110.00:
(1 )HF7VX. St50.CX3. (210)435-6190. BNB435
RADIO DOCTOR VJDEOS for Repair f^nd Align*
meni ol HF Trans ceivers. Reviewed by Gordon
West, January — 73 Magazine. Videos for popular
KENWOOD. YAESli. and tCOM. ORDERS:
(800)788^1416 MC/VISA. Catalog: SASE (2
stamps): RADIO DOCTOR, 710 Teague Or, Ken-
nesaw GA 30144. BN3442
FREE , . . Ham Radio DX Gospel Tracts, SASE:
N1GDP, RAR-QFC, RO. Box 8. Harmony ME
04942. BNB443
RSPEATER PROGRAMMING SDPTWARE.-Use
yCHlf PC and modem to generate DTMF tones.
Send SASE to KM9S. Box 771 . Franklin JN 46131 .
BNB460
GOOD DX LOCATION on the second highest hill
on Ihe East Coast. Four bedroom yellow brick
house, overlooking Sandy Hook Bay. 65' military
type tower. Call (304)462-5575. BNB505
CRYSTALS; High quality for your VHF/UHF
and SHF iransverter projects. SASE. WA3IAC,
7148 Montague St. Philadelphia PA 19135.
BNB515
CELLULAR PHONE PROGRAMMING PACK-
AGE! Program/Reprogram cellular phone (s^
Change ESN and NAM. Change or Clone ALL.
$200.00 Complete. Call (419)351 ^7713. BNB520
CDROM-94 MAM RADIO CALLSIGN DATA BASE
Ham Radio Callsign Database with hundreds of
PC Compatible programs, radio mods, TCP/IP
Usenet. Ham Radio Archives. FCC Rutes & Regu-
lations. cun^enl exam question pools, and Canadi-
an Call Signs. Only 524.95. with Windows/TX)S In-
terface, tncludes shipping! Send check (o:
CDROM. 2348 Karen Dr,, #6. Santa Clara CA
95050 or call {408 J 241 -7376 with your Visa or MC,
BNB540
- BUY * SELL - TRADE
ALL BRAN[)SOF
2 -WAV RADIOS &
ACCESSORIES
CstJ or Write for
a Cuaant
Flyer
(406)252-9220
1113 Central Ave.
Billings, MTS9 102
C.W. WOLFE COMMUNICATIONS
CIRCLE 2Q ON READER SEI^VJCE CARD
Whereas the Loop?
Wflai v^ttiuJIlI W(if till in thj^ ci'n^io? I IncJ ilv
utup L>a 3 £kii ^tkS Ilk' Klidp m ttk: iLindiiiL
Willi ^ ^-miai tmi Onh iOk T^" in Uk ik:xi
t^irfj S** 1 fm tint" ufi tkjTtri';; thj Stfix^Bii-nl
nlvtt jli ilx* rwiyhhi'r\ ucfij bavy. fcd li wiih coax, Ni»w I m paling
2\}m S5* -film S79 75orSlhii S99 IfiOm St 3^
An ten nan West Or^^ i^uio^^J'™^
CIRCLE 363 ON HEADER SERVICE CARD
Small Talk w
MICRO 1.2 8 2B VOICE RECORDEIt IDENIfflEftS !■
FuiLT mmm in the uiA (hot a hi), \wmm
HHaOPHORE, SWITCHES WO FUli OOCyHEHTATOI
Til b.p*
tm
JVM:fiOi.2s
SHUSZE
8»izSWPI£MIE
5r118 K HffPlT
8 Om SP&UEI CMTTFUT
iMAuncoomfi
nPEATER/nAmi m
-GXEAIfiX BEACON OA FOX KUMUNG
- SlffE TOW VOO DUNNG A CONTEST
' 100 lEAl leWff WTDfOUfT P(WEI
* EXNT mm ErfuunoN
^ 60 SECONDS KHMAT
wo tsr-s^n
R I N c;
\\i\ mtm STIHET SCHEHFCTADf, NY 11303
okhh bt ptiDic m. nuL - in u^a wd v* fouuh - coi). [hmgb APm - m usDum add muiD iui
TO OltDERiCALL l-(800}-588-4300 IISIKS'"''
ADOmOMi. FEATM5 g
jnyii 1HF
-tmmi *m id rma
^ WLT Pit mm
I ^ W^
t: sJiTi A..:^l«ir
CIRCLE 281 ON REAPER SERVICE CARD
Sell Your New & Used Gear In BARTER 'N' BUT
Classified Ads Work[ Call Judy Walker today. 1-800-274-7373
1691 MHz Weather
Satellite System
1691 MHz Pre-amp.
model TS-1691-P. Amp
1691 MHz Receiver
model TS'1 691 'Recvr
Decoder Board & Software
model TS-VGA-SAT4
$250
$450
S349
Low Loss (microwave) Coaxial Cable (65ft)
with connedars.
model 1691'Coax ass'y ffiS
Track l\ Satellite Orbital Program. Tracks ALL
satellites, world map. prirrt out S99
1 691 MHz Loop Yagi Antenna
model 1691-LY(M) S99
1691 MHz Loop-Yagi Extension
modeM691-LY-XTN
$85
Demonstration Disc (IBM-PC VGA compatible)
of signals recorded from WX-SAT system. $3
Shippmg: FOB Concord. Mass^
Prices subject to change wtthout notice.
SI
SPECTF^OM IffTERHAnOiiAL. INC.
Post Otfice Box 1034, Defrt, S
Concortf, Mass, 01742. U.S.A.
Phone: (50e) 263-2145
Fax: (508) Z63-7(iaa
ItfE AfilH^ ES QAP TiCHMlMOl'V •T>4t AMS A f » IS C4P TfOlHOlOC Y
Jill Airtemi wUi No Earih Uss?
1feS.«. the answer Is GAP'S
llACKrABD
}f you're looking lor an anten-
na that can o^jt perKxin the
otlier^ m^ givt you the edge,
you re lookfnQ \x» i GAP. TTie
Chdilenoer OX-Vltl ts the
TTvoliiicnafy design Ih^
9P5MF5 yotf tfmtantk ^
lasAMand opafiiNMi ind
omoled eftioency wtmkMr
thai ifnivafts Evth Loss.
fiAP dEHws trm m «bf]H
4M ^eur pMer dpesit
dtsapfKar mo tsms grounl Put
t up. Tum It on. No tymng. Nfl
frustration. GAP d«livsrs
evQrylhing bul ti^ ha^e^.
And — GAP delivers ai a
fractioa of Ihe cost Qt tfie
'so-called" competliyon.
The ChaNtnoer DX-VIII
Kn- im JAn \im If n IlifB In hn
PjtPWil
$259
Pty^ Shippirig
-JCft. Ft 32967
(4fl7)77S-372a
iintMA nnoucfs .
TNE ANSWER 15 GAP T!£t1NdLOCy -THE AWWf ■ l( pA^ TfCHNOLOGY
CIRCLE ia3 ON READER SERVICE CARD
73 Amateur Radio Today • July, 1 994 83
Where's the Fun?
The 10 mf ttr test bad it jfTtil and 1 expected the bsa^
to open about the titnc I arrived at ihe cnoEeL Rs^ end
gt\ cen were jn the trunk. Mn.\:-J w^as risihi beside.
rolled up inside the bUDCtKf psi Room^uifn a vicu.
Sica tales off trocn ihe balconv slGpin^ dvrwn lo a iree
His tail slips under Ihe door. And Pen 59 in Japan. . .
J-10 J 15 J- 17 J -20 J-30 j4o i?!'
SJ9 $42 $47 $49 $59 $69 jl
Add S6 (tsi & Handling USA & Canada S14 othe«
Box 50062-5. IVo\ cj IJT S4605 800-926*7373
UHF REPEATER
Make high quality UHF repeaters from
GE Master II mobllesl
* Duplexing «id Uming infofma^on
* Tnforrnalk^ wilwut radic
5199
S12
S40
CmCLE 132 ON READEf^ SEP VICE CARD
Versatel Communications
Orders 1-000-436-5548 For info, 307-266-1700
P,0. Box 4012 • Casper, Wyoming 82604
CtRCLE 259 ON READER SERVICE CARD
▼ ELECTROMAGNETIC FIELD METER
Reduce exposure to potentially hirmful
electromagnetic lields. AlphaLab's handheld TnField^
Meier measures AC electric fields, AC magnetic fields
and radio/microwave power density. Find ground faults,
AC current wires or measure high-field generators with
the Magnetic Setting (.2 - 100 milllgauss. 60 Hz); identify
poorly grounded or shielded equipment, high VPT or
fluorescent light fields, distinguish hot vs. ground wires
WJth Electric settfng £.5 - 100 kV/m, 60 Hz); measure
amenna radiation patterns, leaky microwave ovens, etc,
on RF/microw3ve setting (50 MHz to 3 GHz, .01 to 1
mW/cm*).
Electric and magnetic settings are omnidirectional,
measuring full magnitude of fields without the need to
reorient the meter. Price of $145 Includes delivery and
one-year warranty.
AlphaLab, 1272 Alameda Ave, Salt Lahe City, UT 84102
Call (801) 532*6604 for speedier service or free
literature on electromagnetic radiation health risks.
Sell your product in 73 Amateur Radio Today
Call Dan Harper today, . , 1-800-274-7373
"FIBERWHIPS"
Mobile HF Antennas
ASA
Ma)£UMm MHZ
HfA 6 50.0-54 0
HFAW 210-297
HFAt2 24 69-24 09
HfAt5 21,0^21.*S
HFA17 lei-tflB
HFA2Q 14 0-H33
HfA30 10J-10.1S
HFA4a 7 0^7 3
HfA7B 3 5-4.0
$17.75
EACH
+&6.MSfiH
£SC Re^i^eris Add
5% Sate^ Taxi
Ctwck in AdvajKfl
or C.O.D.
HEAIY GAUGE
NICKELCHROMB
BRASS FimNGS
250 WATTS POimR
AFPROX. 8' LENGTH
AVAIL, IH BLACK
7S 40 30 20 17 1S
ASA
PO Box 3461
Myrtle Beach, SO 29578
1 - 800 - 722 - 2681
100%
'S««rftvli&w
NQ TUNERS
NO RADIALS
NO RESISTORS
NOCOM.PROIVIISE
FIVE EXCELLENT REVIEWS JUST
DONT HAPPEN BY CHANCE
CALL US FOR A FREE C ATALOQ.
n Oti I 7:3. 1 80-4 - 5«pl. 73, 1 ftSS W*reh 7J, 1 9M
CO.Ok. ISSa M«r.W.fl.i1
BILAL COMPANY
137 Manchester DrJvt
FlOftttani. Colorado @0d1S
(719)667.0650
M44.>^C«nt
CtRClJE 42 OM READER SStVICE CARD
CB'TO-10 METERS
We specialize in CB radio modification
pfans and hardware. Frequency and FM
conversion kits, repair books, plans, high-
performance accessories. Thousands of
satisfied customers since 1976! Catalog $3.
CBC INTERNATIONAL
LOU FRANKLIN/K6NH Owner
P O BOX 31500X, PHOENIX, AZ 85046
HamWindows
Your gateway C0 tfi€ worid
Software chat cotnbfn^s the tmateOT radio
with a persofiaf computer
HiDjVrcrtdowi, Ik^ 1 IIJ L Padfit Ccwi Hwf^ Svite LZOC
CwMudcJ Har. CA f li£5
1TI4)71#-4ZII fAX |7l4}644-4tTT
CIRCLE 345 ON READER SERVICE CARD
DACRON ROPE, WHY RfSK FAILURES wiitfi aerial
supports? Strong, high UV resisiant, nor>-stretch
Military Type black DOUBLE (unlike Our competi-
lors' Sir>gle) braided Dac/on. 3/32": S,06m., 3/i6*
(770 lb. test): $,117!t. 5/16": S.IMt. DAVIS RF CO*
24 HOUR ORDERS: (800)328-4773. BNB5S7
DONT BUY QSt CARDS UNTIL YOU SEE MY
FREE SAMPLES. Also I specialize in custom caids
and QSL business cards. Write or call for free sam-
ples and custom card ordering information. LITTLE
PRINT SHOP, Box 1160, Pflugervlile TX 73660.
(512)990-1192. Mastercard and Visa now accepted.
BNB595
WANTED: Western Electric tubes and other lube
audio equipment. (800)251-5454. BN661 S
DU?>LEXER TUNING GUIDE. A complete bookJet
showing step-by-step instructiorts on tuning all types
of duptexers. included is tfieory of opera tkm. de-
tailed diagrams and much more. Serxl 19.95 plus
S2.50 £&h to RGH PUBLICATIONS. 533 Main
Street. Hiilsbcro NM 38042, For raster service using
a mapr credit card call {505)895-&333 and order ICh
day. 30 day money back guarantee, BNB635
SATELUTE EQUIPMENT Besl S$S USA. (800)851-
6534. BNB640
UNIVERSAL PROGRAMMERS Data ID. XELTEK,
Logic Devices. Magic lO, EETools, Needhams, from
$399.00. EPROM programmers ffom $117. Call for
free catalog, (408)241 -7376. BNB645
VHF-UHF^HF Large SASE. VHFer, RO. Box 685.
Holbraok AZ 86025. BNB660
QSLS—ELEGANT, AFFORDABLE* Samples $1
(refundable with order). AACO, Dept. S47. 1639
Fordham Way, Mountain View CA 94040. BNB670
HAM RADIO REPAIR* All makes and models. Fast.
Professional Sendee. AFFORDABLE ELECTRON-
IC REPAIR, 7110 E, Thomas Rd., Scottsdale AZ
65251 . (602J945-3908. BNB7D0
ROSS* $$$$ NEW JULY (ONLY) SPECIALS. SAVE
TIIVIE AND MONEY HAVE MODEL NUMBER AND
MANUFACTURER READY WHEN YOU CALL OR
WRITE. KENWOOD. LH-3, $35.00; PB-IO, $40.00;
TH-315A, $340.00: TH-22AT $250-00; AEA PK-
232MBX, $298,00: PK-64A/HFM, S145.00; ALINCO
CALL; YAESU FT-416/25B. $255.00; FT-470,
$355.00; ICOM 3230. $635,00; 3P'23. S30.00; BP-
70. $63.00; 707 $815,00;; 04AT S250.00; 471 H.
SI. 150,00; MFJ 81 5B, $53,50; 1264. $3.00; 1265,
§14.00; BENCHER CALL: BUTTERNUT CALL;
CUSHCRAFT A3WS. S250.00; AR-270. 557.00;
TELEX HY-GAIN, HAM-IV. $325,00; 12^. $360.00;
RF CONCEPTS CALL; MiRAGE CALU LARSEN
CALL. LIMITED TIME OFFERS. LOOKING FOR
SOMETHING NOT LISTED OR HARD TO FIND?
CALL OR WRITE, OVER 9000 ham-related items in
stock for immediate shipment. Mention ad. Prices
cash. RO.B. Preston. HOURS TUESDAY- FRIDAY
9:00 TO 6:00. 9:00-2:00 RM. MONDAYS. CLOSED
SATURDAY & SUNDAY ROSS DISTRIBUTING
COMPANY, 78 SOUTH STATE, PRESTON ID
83263. (208)852-0830. BNB707
ELECTION TUBES: AH types and sizes. Transmit-
ting, receiving, microwave . , . Large inventory =
same day shipping. DAILY ELECTRONICS, 10914
NE 39th ST. Suite B-6. Vancouver, WA 98682.
(800)346-6667 or (206)896-8856, BNB71 9
MINIATURE POLICE RADAR TRANSMRTER One
mile range, S41 assembled, $31.00 kit. 9025 Cold-
water Rd Bldg. 100A, Fort Wayne IN 46825,
BNB725
B4 73 Amateur Radio Today* July, 1 994
SKYWARN SPOTTER'S ^ STORM CHASERS:
^'Slprm Spotter's Video Field Guide" now available
on VHS. Learn how to intercept and monrtor devel-
oping tornadoes. Thorough spotter training with
beautiful computer storm simulations, vivid storm
video examples, narrated by personable TV mete-
orologist Million times better than any slide pre-
sentation. $24 J9 each plus $2,00 shipping to:
Dave Oliver, RO, Box 3372, Amarlllo TX 79116-
3372, BNB750
HAM RADIO REPAIR—Prompl service. ROBERT
HALL ELECTRONICS, 1660 McKee Rd,, Suite A,
San Jose CA 95116. (409)729-8200. BNB751
PALOMAR PD-dOO Digital Display, cables and In-
structions to install in Kenwood TS-520, SI 00,00.
N2PTF, (315)884-3045. BNB760
WANTED: HAM EQUIPMENT AND OTHER
PROPERTY, The Radio Club of Junior High
School 22 IMYC^ Inc. is not only the Big Apple's
largest Ham dub but also ihe r^aiion's only futl
time, non-profit organization, worlcing to get Ham
Radio into schools around the country as a theme
for teaching using our EDUCOM-Education Thru
Communication- program. Send your radio !o
school. Your donated amateur or related property,
which will be picked up or shipping arranged,
means a tax deduction to the full extent ot the law
for you as we are an IRS 501 (c) (3) charity in cur
fourteenth year of service. Your help will also mean
a whole new wortd of educational opportunity for
children around the country. Radios you (^n write
off. kids you can'L Enjoy summer by helping some-
one else and yourself. Please, wriie-phone^r FAX
the WB2JKJ "22 Crew" today: The RC of JHS 22.
P.O. Box 1052, New York NY 10002. Telephone
{516)674-4072 or FAX (516)674-9600, Young
people, nationwide, can get high on Ham Radio
wtth your help. Meet us on the WB2JKJ CLASS-
ROOM NET: 7.238 MHz, 1100-1230 UTC and
21.395 MHz. 1300-1900 daily —ALSO— at the
ARRL Southwestern DIv. Convention in August.
BNB762
JOIN TAPR-TUCSON AMATEUR PACKET RA-
DIO (non-profit developers of the TNG). Member^
ship benefits Include: supporting the development
of new communications technology, quarterly
newsletter low-priced software/shareware, 10%
discount on kits and publications. S15/year (torejgn
higher). VisaMC accepted. When joining, mentiori
73, receive TAPR Packet Radio General Info book-
let ($7 value)? (817)333-0000. Mail:8987-309 E.
Tanque Verde Rd. #337, Tucson AZ S5749-9399.
BNB765
SERtOUS ABOUT SOLAR POWER? The PVSP
starter kit comes with a 32 watt Sola rex VLX panel
and a ten amp Sunlogic charge controller. Special
introductory price S275 plus $7 shipping. SUN-
LIGHT ENERGY SYSTEMS, 2225 Mayflower NW.
Masstllon OH 44647. BN8774
FOX TANGO NEWSLETTER Collectors Editions,
Call for years available, entire library, S30.00.
Great for Yaesu enthusiast, INTERNATIONAL RA-
DIO & COMPUTER, INC. (407)489-5609. BNB776
LET ME SHOW YOU the tips and techniques o(
amateur astronomy CLEAR SKIES QUARTERLY
NEWSLETTER. $19.00. MC/VISA/AMEX<
(800)501 '3003. BNB790
AGGRESSIVE SALES REPRESENTATIVE seek-
ing additional employment. Would like to sell ama-
teur radio equipment. {91 0)299-1 298. BNB800
THIS MONTH^S GCX)OiE FROM THE CAMOV STORE
^g KENWOOD t«^Wl* —
«k
UnOtr
1345 00
^knOar Savings on AEA, icom, Asiron.
Crxjfhcrsfi. Allnco. £ic All L.T.Q.
Omr 9000 Ham temv «n %$s>ik, m Pti»s. C^ FDS I
CiMotwri!^. Tc3 saw line and monejf. ria^ ine moM njfttKf masJj"
Today (208) 852-0830
ROSS DlSTRieuriNG COMPAHV
78 S. SlJlfl Slroeil, Pfi>^an. Id. &J2i&3
Hours Tue.-Fri. 9-6 - $-7 Mof>fl3yi5. Cios«l Sat. A Sun
^ • " = ° -_-;
Field Day G5RV QuicKits
^
*■ AmUmnmt Vest Box BtK/ess,
t?T««IOS
CIRCLE 251 ON READER SERVICE CARD
-Fdil^ik wuii IniliiKltns
•EvcfTWoclA^rMed
• Ftalaft mtHuu ia mkuMvn
• KinkpiwrfQukelFkic wur
Tnae AU Ratals Im J WAHC
«*
* JZhKiUc :xz« C3RV
«Sfc9S
2tmi. i«n^iQ Dkpldk
* f 111 f4» GSm^
laus
lO^flSO^IOOlipqlt
-HaUSuGSm-
*nMs
Slft ^^J-luApol*
> Qb^«* 51^ C$RV
fsm
^bftmioupot*
- ^»idyu.ust loa h GSiPf
fsan
■ H*j^lM4t Si ft. cmi/2
H&I3I1
-2r«t. UnminSHika
tlL.«
Older EbilLiBB- A4d U Fftll
L'90l'373-a43Q
CmCLE 29€ ON READEf) SERVICE CAfID
^tam^ AMIGA AND COMMODORE SUPPORT SERVICES C^
Now utifizt the s^me repair faciiifies
used by dealers and other
Commodore service centers. Take
advantage of direct fow pricing, fast
turn-around (24-4$ hours}, extended
warranties, service contracts, low-
cost system upgrades (such as 1
MB Agnus), Toast Br problems and
most important ^PHOFESSiONAL
SERVICE.
CALL FOR RETURM AUTHORCATIOII NUMBER
For every piece Of equip mefH repaired and felumed to our ^u^om&j^, we
vnll include one of tl^e folEoiMng FREE:
• A CofTimodiore or Airig^ diagnostic dinette (SlO.OQ vslue).
• A CofnmodDre Di^gnosuoan or Amiga Tmuble^hooter tSiO,00 vaSuG).
SPECIAL LfMITED TIME OFFER
Between now aixl August ^5th, every customer who sends
us their Amiga for repatr has the option lo purchase
"Where in the World is Camien Sandiego" software for the
low price of $10.95. whiJe supplies iasL
COST OF SERVICES*
GLOBAL UPGRADES, INC.
3 CHESTNUT STREET, SUFFERN, N.Y. 10901
914-357-7339 • FAX: 914-357-6243
1-800-426-8693
HOURS »-eE.T.MON.-FHI.
1 (i.jUH
AMIGA
FLAT RATE LABOR
A500 $S5
A2O0O sa5
A3000 S119
A400Ct CALL
■PLUS UPS SHIPPING
COhAMOOORE
FLAT RATE LABOR
C64
$25
ci2e
S45
1541
S30
1571
^oo
CDTV
$eo
aLL FOR PRICING ON KC'NITOF REPAIR fi OTHER ITEMS WE SERVlCf
CIRCLE 338 ON READERS SERVICE CARD
Sell Your New & Used Gear In BARTER 'N' BUY
Classified Ads Work! Call Judy Walker today. 1-800-274-7373
"aNlXNC" t,S. & LVTTR-SATIONAL
CAIJ. DIRECTOilY
OVES A MtLUOS CALL SIGNS
Hamcall online service gives you ALL hams
via your computer & modem. Updated each
month! Oit/vS29.95 per year, Unlimited use -
24 hours a day - you pay for the phone calL
»00:2«2-5623i * 70.^:894-3777 * FAX 703:894-9141
r X 1
LlCKlMIASTEF^
U U I, I B IH I N C3
CIRCLE 7 ON READER SERVICE CARD
Say You Saw It In
73 Amateur Radio Today
P.O. BojcMi
e03-32g^&95
nrniMo Ttw AIM Tiijf HACK iNHAOc FAX 603^329^499
FUN-KIT LINE
IMPROVED! SMART BATTERY CHARGER KITS
tCONT. OUTYCHAKGER FOft LEAD-
ACIO/GEL CEL). USES UC3&O0 1 C , QUALrTY
COMPONEhTTS: PGB MOUNTED PWR XFMR.
AhlMETER ENCLOSUr^ 4 ASSEMBLY
KAKUAL11(V22iO VAC. SO'WKE NOW
KAS REVEF^E aATTWflTY PROTECTION, TRICKLE START UP.
LAROERHEATB^HK. IMPROVED SOFTWARE. ANO
PaOVmiOMS fOR EXTERNAL CURRENT SWfTCHINa,
GIVE YOUR
HR-2510 HR-2600
"BIG RIGS"
CHIPSWITCH
4773 Sonoma Hwy. Suite 132
Santa Rosa, CA 054O$-42fi9
Write or aJl fTQ^) si^t-aSiz iw fri-T. lurbrnutlon
CJRCL£ 265 ON READER SERVICE CARD
Quality Microwave TV Antennas
Obit System
LIFETtME
WARfiANTV
WIRELESS CABLE ■ IFTS - HH&S - AmaUvf TV
ur^ Hp$Ii Gain S04b(+) *'ta«Ate 1J li ^7 6k2.
* SS-Cnanrtet Otsh Sysdem $i99^
- 36-Channef Cfeh System $M#.9S
* 20-Cliannei Dtsh System St24^
* fin A^iiiiit, CflfflgWrt&,_Olft^ Tinig ^iWii'
* Cai or vrfli FSASE) lor fKE" QiaaMQ
mUK-TBai ELHm«fflCS
PiL Bm B^3 * Scottsitate, M 15252
f602) S47-77IXI (S3 00 Grfrdit ^W ptrone orders]
UC'DEUBCXX)
CS.LS
vOlTlkGE
fr;i>6
3 0,
worn
*
ftD.
BC12
$
laa.
&i:t4
7
\A^.
ecie
&
1*0.
BC20
10
20 0^.
fiC-XX COMPLETE UNIT WITH ENCLOSURE ...„., $ 84 fl6
8C-XXA BCXX WO ENCLOSURE OR METER S 4* flS
BC-XXB B(^XXA LEBS XFMR:^.,.,„,„,H.^.Mt»Ht..^.MHM. * M «5
BC04. THE Paul Bunyan of Battery Charoinq. past
RECOVERY FOR 6 OR 7 CELLS. ALL FEATURES OF 6C^Jt>C UP
TO 5 AMP CHAROlh>G RATE, 10A METER, HEAVY DUTY XFRM,
APPLICABLE TO DEEP CYCLE HIGH POWER USAGE ALL METAL
3 5" X 8 6- X 1 0* E NCLOSURE EXT ERNAi HEAT SiMK 1 1fl VAC &&
HZ ONLY- ABOUT 13 LBS , ^ ^__,.. «. |180 95
N
E
W
"SMART" SOLAR CHARGER FOR lEAO-AOOf (SEL-
CELL BATTeftlES CHW^GE YOUR BATTERIES WMENTHE
POWER IS Of Fi CHOOSE SAUE VOLTAGE RAMOE AS
9C50f »«EDS SOLAR PAJ«L 4 VOLTS MK5MER THAN
BATTERY VOLT AOe ...^._ ,..,..,™.,_„^ f *«»
KR01. CURTIS KEYEH lOT uses the wjwaBM chip
4-12 VDC KIT INCL ClRCUrT BOAie). AUDtO AMP AND PARTS
SUPPORTS IA|Mi»C KfYtNO. ADJUSTABLE SPEEO^ 5 - 50 WPKI
KEY AND ENCtOSURE#lOT INCLUDED f 38.fi5
WA, WUTTRCARD, check on bOMEVOAOCnAcOEFrtO
USA SHfP Ca^t 15 00 roH isrSt DO %\^ won CA- AOCfl I1€0
CIRCLE 249 ON READER SERVICE CARD
CIRCLE 22S ON READER SERVICE CARD
73 AmatBur Radio Today * July, 1 994 85
FIELD DAY ANTENNA
\ii ► prun tng^
No*rv4**fe'' l;*n*t
4^
T>rr KfticHUw w » or, JOl 29. 17- ti iO TNrr/3 i^No^tync rfl 4CL
2ft. 1 A W(wl «iiw lwi><b w/ Inner. CK£ k C*Lti its* wr/ f rtquCfiCy-
R<nKtv tfllisc ft Kmk-fituf So Trian at ttanltm%
3i^^ S0062S, Provo, UT S460& rtffif 801 -373-8425
Amateirr Radio Language Guide
• Hunilcie^ iif phrases, especiatty <or ttie ham radio operaiof
« Vot. 1 - Frenctf . SiiMM, Geffnar. Japanese, PfMh
p Vol. 2 - Siwcish, Italian. Po4lugiese, C/oaitan. ^torwegian
• Vd. 3 - Russian. Dartcsn. Czech, Korean. Haweiian
■ Vd*. 4 - C}\ffT«se. Ouicft, Finish. Romanian, Vi«n*r«s«
" VoL 5 ' Hunganan. Amtic. Riftpni, Tuifcish, irxtonresisn
SentJSiO. pcf vokirne US., S^2 otjtside U^, to
ROSE, P O Bqx 7^, Mundeten. H €0060079©
Speak To The World
CIRCLE 134 ON READER SERVICE CARD
CIRCLE 135 QH READER SERVICE CARD
,Q
lh& BbI in K b
aSH^^mf
MlyAFTWeath&rSoidfi
bw Ptice, Advamgd^f ui:Featurei
v^oflware cmdficirdware Solutionis
fOFS WeofherrAX
^^High PerformoiKc
lliiKte Weathef
jj4 Phdht/Fox
%ft
KT'^'onrHin<{(a
'^iiwRi«^'^
'^ _ \
6404 l^kerost Ct,
i,NC 27612
A(i¥iiii<«d Capture ionril
Removes Oappler kndmg
Sdf Ifst mtjdes vefffy operafion
FCC Port 15 CIksB certified
Cjoffldim botli AM {»kI FPU decoien
Ullio fost 2as A/D fcfrv^rlir
AutDmolk Gflln Lock (A€L)
WarjUains f rome SyrK
full fwncltoii Soflwore
SlDTid alone pnimdrion
E^hemerts bosed v^orldwde g&&[M)!iti<
ond biifud^ longitude oirerloy
Diifance & directbci meosureiiiBnt \m\
Extensive image proq^isipg looll ok
Sell Your New & Used Gear In BARTER 'N' BUY
Classified Ads Work! Call Judy Walker today. 1-800-274-7373
How To Get Started
In Packet Radio
Enier the exciting
world of packet ra-
dio today with How
To Get Starred In
Packet Radio. Dave
Ingram, K4TWJ,
wrote this begin-
ner's guide 10
packet radio in an
casy-to* understand manner. It starts with
a non-technicitl description of packet ra-
dio, followed by chapters that include
getting staned, setting up your station,
networks, BBSs, portable and high-fre-
quency operation and even a Packet Ra-
dio Equipment Survey. There's also an
appendix that includes circuits for inter-
facing equipment. Join the most excit-
ing and rapidly growing area of ham
radio today! Order your copy of How To
Get Started In Packet Radio book for
only S9.95! (plus $2.00 S&H).
CALL US
TODAY!!
NARA
P.O. Box 598, Remond, WA 98073
Orders Only 1 -800-GOT-2-H AM
Inquiries (206) 869-8052
CIRCLE 223 ON READER SERVICE CARD
EVERY ISSUE OF
73 Amateur RadioToday
on Microfiche!
The entire run of 73 from October,
1960 through last year is available.
You can have access to tbe treasures
of 73 without several hundred
pounds ofbulky back issues. Our
z4x fiche have 98 pages each and
will fit in a card file on your desk.
We offer a battery operated hand
held viewer for 575, and a desk
model for $260. Libraries have
these readers,
The collection of over 600
microfiche, is available as an entire
set, {no partial sets) for $285 plus
$5 shipping (USA). Annual
updates available for $10*
Satisfaction guaranteed or money
'^^'^^ ^UCKIMASTER
Route 4, Box 1630
Mineral, Virginia 23117
703 : 894*5777-800 : 282-5628
Iptemet: info@buck.com
Fax 703:894-9141
CIRCLE 16S ON READEa SERVICE CAHD
AMIDON TDROID COIL FORMS AND KITS for
Ham projects. Interest to Radio Amateurs, large
stock on hand. IVAN JOSEPH, 3116 West Janath
St. DepL 73, Ctiicago iL 60645. (312K65-S683.
BNBeoa
H,390A— SALES— SERVICE'-PARTS. Info
SA3E: MILTRQNIX. RO. Box 3541. Toledo OH
43608. BNBei 3
FREE \BU SHAREWARE AND HAM CATALOG,
Morse Code Computer Interfaces. $49.95. DY-
NAMIC ELECTRONICS, Box 896, HartseJte AL
35640. (205)773-2758. FAX (205)773^7295.
BNB81 5
MORSE CODE MUSiCLDo Aerobfcs, Sing, or
Jog, white learning code! Sensational new dis-
covery and now the secret is yours! Order THE
RHYTHM OF THE CODE cassette today! S9-95
ppd KAWA RECORDS P.O, Bost 319-S. Wey-
mouth, MA 021 88. The HIT of Ihe Dayton Hamven-
tionl BNB824
WANTED: Kenwood R600 Receiver also McKay
DYMEK DP 40 pre-selector Rick, N6NVG.
(510)687-2719. BNBSSS
OVER 3500 AMATEURS WORLDWIDE ARE us-
ing Bandmaster Quad Antennas. Discover why-
Free catalog. AAE. 3164 Cahaba Heights Rd..
BErmlngham AL 35243. (205)967-6122, (205)970-
0622 FAX. BNB830
THE ANARCHISTS BBS is a resource for anar-
chists, investigators, researchers, ramputer hack-
ers and phone phreaks. Catagories incude: Com-
puter hacking, investigation lechniqyes, Telecom*
munications technology and Surveillance, Call
(21 4)289-8328 for free trial access. BN&831
FCC COMMERCIAL LICENSE PREPARATION
RADIOTELEPHONE-RADIOTELEGRAPH, Latest
home study fast easy audio video. O & A pool
disks. FREE details WPT PUBLICATIONS
(800)800-7588. BNB840
ELECTRONICS GRAB BAGI 500 pieces of new
components: inductors, capacitors, diodes, resis-
tors. $5.00 postpafd. ALLTRONICS, 2300 Zanker
Rd., San Jose CA 951 31 . BNB855
WANTED: COLLINS ANTIQUES, anything old
from, speakers, receivers, transmitters, and all ac-
cessories, any condition. Top $S$ paid. Rick.
(800)462-2972 anytime. BNBS65
SGC, INCm an HF SSB radio manufacturer has
openings tor technical safes and support persons.
Must have ger^ral dass license, good veitial and
written sKills, Knowledge of marketing, dealer net-
works and marine industry helpfol. Must be wilfing
to travel Send employment resume and salary his-
tory to; SGC, INC.. PO Box 3526. Bellevue WA
98009 USA. BNB880
SCHEMATIC DESIGN PROGRAM. Free brochure,
write Dept, 7. SCHEME-ADDICT 8622 Wesf 44m
Place, Wheat Ridge CO 80033, BNB905
PRINTED CIRCUIT BOARDS for 73, QSZ etc.
Club orders welcome. US orders deduct 20%. Free
Pst. O-C-O ELECTRONICS, Box 20304. 858 Upper
James St., Hamilton, Oniano, Canada L9C 7M5.
BNB91D
WANTED: BUY AND SELL All types of Electron
Tubes, Call (612)429-9397, Fax (812)429-0292.
C & N ELECTRONICS, Harold Bramstedt, 6104
Egg Lake Road, Hugo MN 55038- BNB915
86 73 Amateur Radio Today* July, 1 994
COMMODORE 64 HAM PROOeAMS-e disk sides
over 200 Ham programs $16*957$.29 stamp gets
unusual software catalog of Utilities, Games. Adult
and British Disks. HOME-SPUN SOFTWARE, Box
t064-BB, Estero FL 33928. BNB917
HERO ROBOT AND ROBOTIC EQUIPMENT
OWNERS; board repairs. IC programming and as-
sorted pre-programmed speech chips. For addi-
tlonaJ requests contact: ELECTRONIC REPAIR,
2927 East Washington Ave., Madison Wl 53704.
(i06)249<5577. 6NB920
RADIO REPAIR Amateur and osmmercial, profes-
sional work. Fred Fisher WF9Q. 6866 W. River
Rd., South Whitley IN 46787. (219)723-4435.
8NB930
SERVICE MONITORS . WANTED
SERVICE MONITORS WANTED
Any late model Test equipment
Call (408)241 -7376- BNB945
RF TRANSISTORS AND TUBES HEEDS DEAL-
ERS and repair shops lor 2SC1969, 2&C2879,
MRF455, 2SC1307 and more. WESTQATE
(800)213-4563. BNB950
FREE HAM QOSPEL TRACTS. SASE. N3FTT.
5133 Gramercy. Clifton Heights PA 19018. BNB960
raiNTED CIRCUIT BOARDS for projects in 73,
Ham Radio, QST, ARRL Handbook, List SASE.
FAR CIRCUITS, t8N640 FleSd Ct., Dundee IL
601 ia SNB968
HANDY TALKY CASES, black or camouflage.
SB,95: personalized, Si 4.95; desk stands, $8.95;
specify make & model, add $8.00 for s/h. Send
SASE for catalog, R. THOMSON, 165 Wellington
SL. Suite 28010, Barrie. Ontario, Canada.
L4I47W1. BNB967
AZDEN SERVICE by fomier factory technician.
SOUTHERN TECHNOLOGIES AMATEUR RA-
DIO, INC., 10715 SW 190 St. #9. Miami FL 33157.
(305)238-3327. eNB979
ROTOR PARTS ROTOR SERVtCE. ROTOR ac-
cessories: Brak-D-Lays, Quik-Connects, Pre^Sal
mods. NEW models for sale. Free catalog,
C.A.T.S,, 7368 State Road 105, Pemben^ille OH
43450. BNB996
I
Sell Your
New & Used
Gear
In Barter 'n' buy
Classified Ads Work!
Call Judy Walker
today at
1-800-274-7373.
ULTIMATE MODfFICATION BIBLE
HlfOST COMPLBTB,
GmaATEST IH TTSTIMEt f !
OVER fiOO MlKJi WlEi2;55 CB- HAM.
mm &a coMi'Lerg crystal chains
awm i^schMHw^ HOD.
TEV USTEB RAE'SO MOD.
UKEAR ^AX ANT. IS?0.
OVER aoO PAOES OF INPO
KDC SOUND 1-800-256 9S95
5 PINE MEADOW
CON ROE, TX 77302
f UUmJvTE^
0 BIBLE 4|
I '"iini KfiF Lanf^tft- ^* I
CIRCLE 151 ON READER SERVICE CABD
walUpg hKt ?W Otmt In « bOfll« lin you TwedTyll-Ejuivang
CaA hjrrt lorth and Ni iBIIstcrHng black wt^lhier ssjilQd hnti
rev«Bt ■ fclcRk eni^ccf ho^awft anlttih* rua^ to hAngi irywNir* Sui-
ptm ifi tfit apSflnwK ckicel or p«t» llOCffvay, AlOcn PICv-J \o ^.-indow
i^»» tr ^vfiMFT ml Hit rmtOk no iwUi tor brwMkim^ iow.
inform h»Vwawe
n^B-J BPffiii leady br BOfk itMt 73" t^atati caatut
U.S.A.
I^1d$1
Antennas West
Ofthr Hotifne
eOI-373'8425
CIRCLE 89 ON HEADEfl SERVICE CAHO
Texas
BugCatcher
^ The SERIOUS HF Mobile Antenna"
fcfe
Unmatched in Quality
Unmatched in Performancel
CALL OR WRITE FOR
FREE BROCHURE
GLA SYSTEMS
PO Box 425
Caddo Milts. Teyss 7^13S
903-527^163
Ws c^ft supply mvBrything you rm^ for that
BIO mobito signatyou have always wantsdf
Ths T&xas BugCathcer c^n i>a eustcm
d^signeti to ffS YOUfi pafticular vehtdie.
Are you ready to own the BEST???
HENRY ALLBJ WBSTYD - - TiMA ^LIEN
FOLD-AWAY
ANTENNA MOUNT
f^
FOLDS TO ALLOW DOORS TO OPEN
FOR MINI VANS AND UTILHY VEHICLES
BOLTS TO TRAILER HrfCH OR FLAT PLATH
SUPPORTS LARGE HF MOBiLE ANTENNAS
MOM FOtD OVER MOOeL ALSO AVAILABLE
CIRCLE 124 ON READER SERVICE CARD
Sell your product in 73 Amateur Radio Today
Call Dan Harper today, , . 1-800-274-7373
Ever wish
you had a radar gun
in your car?
m!^^^^
^^^■:s%
'■ ./5\
The ZAPPERis an
awesome Answer!
This magic-like lillle box activates any radar
detector within 3/4 of a mile. Waich the brake lights
come an di€ speeding spons car thai just flew by.
Keep those speeding big trucks from eating your
bumper. The ZAPPER is alOGHz amateur transmit-
ter the size of a cigarette pack, operates on a 9v batleiy.
Complete wi!h toad game Trolling for TaJiights".
BuiH i ttjned only *f*l Plus $5.00 S8H
TRANSEL
TiCHtmLoeiiS
MADE IH USA
123 East South Street
Harveys burg, Oh 45032
1-800-829-0321
CIRCLE 11 ON READ&R SERVICE CARD
Subscribe to
73 Amateur
Radio Today
Cat!
800-289-0388
^FLYTECRAFT^ SFZ
Indoor Multiband HF Antenna
Wi>r1; aU7 I [F binds bciwcen 40 ind 10 meters! •Adjust-
able height bciween 7' tnd 12' lor use between floor and
ceil big, DismiiiUti lo 3*-^'- ■Gnait for outdoor use mIsd!
# Top qujjity ciMtsimctiofli -bright 6063 -T8 thtminum^
fiberglass ceiner section, bc4vy-duiy BAW center coiL,
fUizticss ilecl hirdwii^ « Wc?rki welt insiik most buihl'
ifi|;5. • Anlcnnjs ire comptctc - use your omn [um^.
Erifumatch^ or L-n^woiit to mafdl 1q y<?ur tnoK^ivcr,
• Uses shofi counttrpotse - no gri>und needed. • Scis up
and dismantles ^^'iX *'^^ quickly. • Complete insmiclions
supplied • DON'T let anlennH restrict lonis or Inublllty
Id install villennEs keep you olTthe air!
S17?,95 + $lOSm
Send Qwci/ S Order
to: hX^TBZRAFT"
RO. Box 3i4J
Simi Valley
CA 93093
«00 • 4Sd - 127 J
Tor Visa/MC/lnro
M-F 9A-5P (FD
De&la' inqMiriifs invHed
For 75^B<0 indoors, use
ourSF2-75 HclicaL
S12*.95 + ¥iOS/K
Enjoy
Your
QSO'S
with
^
CIRCLE 251 ON READER SERVICE CARD
73 Amateur Radio Today July, 1994 87
■^
Ham
9 §
Nuinber 2d on your Feedback card
M OUTPUT
David Cassidy NIGPH
Vm Back!
You though I you'd gotten rid of me.
dWn't you? You ihought, "Cassidy has
finally slopped beating his head
against the wall and given up." didn't
you? Ha, Ha Ha ... No such IlcW
Actually, an overw helming nu miser
of readers called or wrote, demanding
that J break the setf-imposed silence
and resume writing this column {OK.
OK. it was only 12 lettefs). To that
brave dozen go my heartfelt thanks. It
you're wondering why i took a few
months off. It's simple. Orie. 1 was try-
irtg to put together the Amaleur Radio
Child Search organiZ3ti<Ki thai I wrote
about back in Febn^ary (more on this
later). Second. I stmply ran out of
things to say. Sure. I could have put
together a coupie of puff pieces to gel
me over the last few months> but
frankly t have more respect for you
than IhaL Judging froiti my mail, most
of you who read '"Random Output" at
least have a pulse. Many of you can
actually write a decent letter and form
a logical argument, either agreeing
with me or disagree irg with me (more
on this later, too). I figured you would
be able to tell thai i was spinnnirvg my
wheels so, unlike many of the writers
in this field (no names mentioned,
please), I simply decided to say noth*
Ing, since f had nothing to say,
I don't write this cotumn to feed my
ego (corttrary to what some of my cfft-
ics say), r write this column because I
think ham radio ought to be more than
chasing DX and giving out signal re*
pofts. I think hams should be involved
and concerned atx>ut their hobby and
about the world ancHjnd them. I try to
send out sparks in this column, and
hope that at least one person will give
some thought to whatever topic I bring
up. I don't wan I you to agree with me.
but I do want you to think and develop
youf own opinion aiiKXlt tJ^ngs. Jt noth*
ing else, I hope my column can pro*
vide something to talk about during a
QSO, other than the make and model
of your store*bought rig.
Amateur Radio Child Search
To pick up where we ieft off a few
months ago, you'll recall that I re-
quested those of you who were Inter-
ested in assisting in the formation of
Amateur Radio Child Search to drop
me a note so I could gauge whether or
not the idea could get off the ground.
I received three letters telling me
why \ shouldn't even try to do this. }
think you can figure out where I told
those naysayers to go. I received a
phone call at my home on a Sunday
affernoon, and the caller got angry
with me when t suggested that it
would be more appropriate if he con-
tacted me during business hours at
my office. I even received a call from a
high-level employee of a well-known
national service organization, outlining
a possible funding source \ asked him
to send me some info so that t couki
prepare a proposal for his or^niza-
tion, but he never did. t don't have this
gentleman's phone number (I know,
that's my fault), so that avenue turned
imo a dead ertd (at least so far). TT^t
was disappointing, because a single
source of funding would have made
this idea an Immediate reatityH I was
{and am) willing to do all the organiz-
ing worit, travel, and whatever else it
takes to get this going, but a commit-
ment o( funding from a major organi-
zation sura wouHd make tl a lot easier.
When you take out the flakes.
kooKs and nuts, I received approxi-
mately 60 responses from people all
across the country, pledging their sup-
port. Over 100.000 people cast their
eyes upon these pages every mkonth
(if you believe the research that Shows
most magazines are read by at feast
two people). Even if you only take our
paid circulation figures, at least
50.000+ people had the magazine in
their hands. Sixty responses out of
50.000 p&(^ie is not what I woukj caJt
an overwhelming outpouring of sup-
port. In fact, I'd call it downright em-
barassing.
To those who responded, I regret to
telt you that il doesn't look like thfs
idea is going to get off the ground. I
would urge you to think about formirig
a local group, or making it a club ser-
vice project to contact local law en-
forcement and set up something like
what I suggested- You don't have to
make it fancy. Just be prepared to pn>
Vkte an organized ar>d trained search
group for whenever your local law en-
forcement agency needs it. If you
need my help, give me a call (at my
office, please). I am keeping a
database o{ all of you who wrote to
me. If a funding source does present
itsetf. t'lf be in touch.
Out-of-Band Radios
My column on the use and owner-
ship of radios capable of out-of-faand
transmissions generated the most re-
sponse of anything I've written in the
last threfi*and-a-ha]f years. Unfortu-
nately, the reading comprehension
level Of some people isn't what it
should be. Either thai or many of you
didn't bother to read the whole artJde
(the lact that the dosing parngraph of
my original text got chopped off with-
out my knowledge didn1 help, either)-
Many of you sighted the regulations
giving us permission to use any
means at our disposal to save life or
property. Many of you simply thought I
was trying to confiscate your radios, f
got accused of being a socialist (which
Continued on page 80
Propagation
Humber 29 on your fewtoack card
Jim Gray WIXU
210 East Chateau Circle
Payson A? 8554 1
As I write these words (late April), the
month of July does not k>ok partk^ulaity
good for HF band propagatton. There
are several reasons for this: generally
declining sunspoi activity; htgher daytime
absorption of signals during the summer:
probable violent magnetic field storms
which would adversely affect the iono-
sphere, hence Hf band propagation dur-
ing several days surrounding the 10th.
16!h, and 29th; and possible other geo-
physical events such as hurricanes, vol-
canic eruptions and earthquakes. That is
not to say they iv/W occur, or that— if they
do — they will happen in the U-S.A. How-
even my records taken over a perkxl of
ahout 1 6 yea rs indicate a very high prob-
ability ol such events taking place when
the sun*s disturbances cause strong
magnetic field disruptions on earth.
On the positive side of the ledger, it is
interesting to note tl^t when HF bands
are the poorest it^ VHF bands are often
the t>est , . . and that can happen durtng
this TTx>nth. Theie will be meteor shower
propagation (delta Aquahds peaking on
the 29ih), and a possibility of
strong auroral and sporadic E
ionization on or around the dates
given above. Sporadic E propa-
gation via fast- moving ion clouds
often results in sfiort contacts on
10, 6 or 2 meters with very k?w
path loss and high signal tevets.
The band-by-band situation
looks very much like last month's
forecast.
Jim Gray WIXU
30 and 40 Meter Bands
fsiighttime DX between local sunset
and sunrise ought to be good- to-excel-
lent on days marked Good (G) on the
chart, and often on Fair {f] days. Thun-
derstorm activity usually abates several
hours after sunset, but QRN will ob-
scure weak signals. Day and night shori
skip will occur on many days, with day-
time skip averaging up to 1,000 miles
and nighttime skip up to 2,000 miles.
Beware of high absorption levels around
k^catnooa
SO and 160 Me^BtfKJs
Forget any daytirrte activity, but when
conditions are Good (G) you may well
discover occasional DX at night, espe*
cially when QRN from thunderstorms
isn't present. There will be few. H any,
really good OX contacts on 160 or aO
during July. Shofi skip at night, however,
can be pretty good out to about 1^000
miles or so,
Always listen to WWV arxJ the propa-
gation forecasts at 16 minutes after any
hour, when up*!o-date reports of Boul-
der K and A indexes are given along
with solar flux readings.
10 arKi 12 Meter Bands
Sporadic E during daylight
hours on many Good days (G),
with strong skip signals from 500
to 1 .500 miles, and with abrupt
tefmir^ation of contact as the ion
doud moves out ol range.
IS and 17 Meter Sands
Good sporadic E contacts be-
tween 300 and 1,300 miles on
most Good (G) days. Also, you
may find trans-equatorial skip in-
to the Southern Hemisphere,
with decent but not outstanding
signal strength.
20 Meter Sand
Consistent DX to most parts
of the world on Good (G) days
during daylight hours, and
on particularty favorable days,
often until midnight local time.
This band will be your DX
workhorse .
EASTERN UNITED STATES TO:
OMTT := s CJ » » -: t] u Fl <i 3: 33
AUiSKA
u; = - ' ^
JiOCWTWN, ' 3£ 2£ 3C <
; 1 S 1 R
■4 'S 1 ! lU
AysnwuA B S i E
«
* _ K
1
CAftA.2Dl«
4
« « <
«'
m
l-i
^^^
«
Ewauuci
[gjf 4Q
^'zr'jaijs'is.el
H/w*n
»
4
Jd
INDIA
JAPAN
P
w
WEXiCO <i «
«
«
ig'
m
-3
"?
ti
ttt
'IJ
0^ll_|Cl^J^p^y^^i (
! ff •
njC^TiO ^SCQ f ■ C ! 4 1 «£
« '
C -5 -4 't • 1 1 -J
tOl^THjy^vO «
C
* 1 * 1 t I *
USSR < 1
1 r I z! [ 1^1
iftrg^coAsr ;: c « c
c*
r|
CENTRAL UNtTED STATES TO:
flLflSXA
L i n
^5r
1
^
?o
AnOElNTINJI,
, if 1 :c
<3
_
sa
3!i
11 a i i|^
AUSTRAL^
14 1 K 1 ?fl JS
4£
M
: a
! a
C*MAL30Sl£ i s s t:
r« C ; ft ' E ' ■!
tHBUim £ « r
sz z: M s rr\
rmmn ' 4 ! 13 ' x ^ ic
S
m K a 1
L 1
P«M t
1 I 1
I
JAPAN ' ' S ?:
, ]^l^'
Nienco is n . xi
JH" 1
ill 1 Ki ' ia ^
II
Tl
1S-
'6
PMIUPPJNES
ID
Hi
^« 23
PUERTO RrCO
11
s
P
3P
«'
«[^
s
ii
If
11'
nr
SOUTH AFfllCA
1"
sEMti
US^R
i
^ ^
s^ 1
WESTERN
ur
JIT
EE
f STATES TO: i
HJn&Ui. • S. . S. '
1 i*
AAOCNtlNA ^^ ' 29 ^ ^ ' «
m
' \v\»
i I
AUSTRALIA !E . K S
S '
c f c' ! ! a
i 1
CAHAt»NE 1 'l~\ IS 1 »
ic
*c
4
. a ! «
li ^ 15 1)
tNaiAND j n 1
s m
jfl
HAWAII 1 10'
Ifi
11
o
»
j^
«'
a JO
S
zs
<'''J^iA . . S
. -^i
-AfAH, 1 \3H »\
^
*
1
v£Mca j -$ :| ^ ' £ ' s'
c'
« ^ =
»J9
*|3
^f
PjE:rx smi -!
-s : E ] Jr
x^
«
r ! _ 1
tr i!i!il
fc&jT*, iFiUCA
4
a'
U*5fl ill'
■
i 1
EAfiT COAST B 1 « 1 « 1 «'
m-
to
^ I i»
■ ■. J^'wii-i, «? "Qni' [iuH
"■TJl
■-C
'■ill* ■
If "
r*'pj
rfl
oii;
iiKrJ 1
■ N
' Pi
IH*F-
SUN
WON
JULY 1994
TUE WED THU
FRI
SAT 1
1 P-F
2 P-F
3 F
4 F
5 F-G
6 G
7 G-F
8 F-P
9P~VP
10 VP
11 P
12 P-F
13 F
14 F-P
ISP'VP
16 VP
17 P
18 P
19 P-F
20 F-G
21 G
22 G-F
23 F
24 F^G
25 G-F
26 F
27 F-P
2B P
29 P-VP
30 VP
31 VP
88 73 Amateur Radio Today* July, 1^B4
/
"What a great fiefd radio.
Mobile, too! I couldn't afford ^.
an HF rig until now,"
<m
''What a great price!
Terrific features, high
performance - and
within nny budget."
**Yaesu did it again!"
ii
FT-840
Compact HF
■fransceiver
• Direct Digital Synthesis
{ODS)
• Frequency coverage:
RX: 100kH7-30MH2
TX: 160-10 m
• IF Shift
• 1 00 Memorv Channels
(independent TX/RX per
memory)
• Twin Band Stacking VFOs
• FM*' Repeater Operation
Automatic 10-Meter
Repealer Offset
w/Selectab(e CTCSS
Encode
• CW Reverse Feature
• Choice of Two Qptionai
Antenna Tuners:
FC-10 Matching Externa)
Antenna Tuner
FC-800 External Remote
Antenna Tuner
• Accessaries:
Contact your Dealer for
full detaJIs.
• Optional
W10*
MEtefl
f a -p
rffl***
vfo-*
STAfiT
SCAIJ
CLAf
^*»
pbwt
PHONES
rjtic ^^ pwfl
Ml"?
I /
sse
cW/**
aw^
iqcv.
CL>"
FI|KCTI0«
—ZT tfFOi^w
•^^Q/W
fAST
M^VFO
SH^Ft
bano
OOSW^
'■';3^'i^-
,f yoLiVe trading up from an older
rig, but have a budget, you want the
most you can afford in top-notch HE
' Tlien the FT-S40 is for yoiL It's right on
the money! Considering a mobile HF or
4 fteld radio and doubt the quality and
features of tiny WV rigs? Then the FT-
840 is for you. It won't disappoint you!
Built to handle rigorous field
operatioOt the new intense LCD dbplay
affords sharp \'isibility in bright sun-
light Die-cast heat sink and internal
thermally switched fan keep the IT-840
running cooL iVIoduIar design circuit
boards ensure operating efificiency —
manufacturing excellence youd expect
in much higher priced radios.
For high performance, the FT-840
features a low noise front end that uses
the latest in PliT RF amplifier design.
Two DDSs and magnetic encoder for
silent, smooth tuning and fast switch-
ing. Tv¥in band-stacking \TOs. And.
automatic M-m FM (optional) repealer
offeet with selectable CTCS& Even two
optional external antenna tuners to
customi;se your rig,
Tbp of the line quality and features
at a remarkably tow price. Just what
youil expect from Yaesu! For high-tech
performance, and a wealth of features
that won't break your budget ask your
dealer about the n^-840.
Performance without corfiprvmise.
sv
© 1993 Yaesu USA. 17210 Eti wards Road, Cerritos, CA 90701 (310) 404-2/00
Sc^ciTicatlons siibji^ct to change without notice. Specif fcaUons guaranieed only wilhin amateur bands, Soirte accessories and/or opllurs are standard in c&naln areas, ChecN' with your tocai Yaesu deafer for specific details.
NWOOD
Spend this summer vacation with the radio you always wante<
Q
TS-950SDX
TS-850S
□
□
TS-450S
TS-50S
Q
TM-241A
TM-733A
Q
□
TM-742A
TH^22AT
TH-42AT
TH78A
r
with great deals from KenwoodI
An industry first! 50-voft MOS FET final amplffier and DSP for superior
linearity, 150 watts output • AH-band HF transceiver with general
coverage recefver • Switehable AGC, sefectabie IF filters with memory, dual-
mode noise blankers. IF notch filter, CW reverse mode. CW pitch, SSB slope
tuning, JF and AF variable bandwidth tuning ■ Built-in CW memory keyer (DRU-2
voice keyer optionat)
Ad-band HF transceiver with general coverage receiver*. 100 watts -SSB
slope tuning, CW variable pitch and reverse controL IF notch, 1-Hz fine
tuning function* Superb receiver sensitivity and extremely quiet noise
floor * SSB HIGH BOOST furtction to bust through ttie pile-ups • Filter options
for botti first and second IF sections * Built in CW memory keyer (DRU-2 voice
keyer optionaJ)
All-band HF transceiver with general coverage receiver, 100 vi/atts
•Wonderfully easy to use, yet high-performance package
* Filter options for superb receiver performance
An exceptional compact, all-band HF transceiver, with 500lcHz to 30MHz
receiver •too watts -DDS with luzzy Logic" control • Kenwood's Advanced
Intercept Point (AlP) ensures top performance with reduced noise floor
Wide band receiver coverage • CTCSS encode built-in • Three power'
settings: 5. 10, and 50 W • 20 full-function memory channels store everything
you need • Multiple scannfng fuTictions
50 watt (144MHz). 35 watt (440MH2) with 5/10 watt settings •'O in V
multi-user programabie memory •72 memory channels • Dual RX on same
band • DTSS selective calfifig with page function ♦AIR for improved intermod
rejection • Quick release front panel •1200/9600 bps.packet compatibie * Wireless
cloning function • Buiit-in CTCSS encoder/optional TSU-8 decoder
2m, 50 watt/70cm. 35 watt modufar FM transcefver • 101 memory
channels for each band • CTCSS encode built-in • Wide band receiver
• Optional modules for 28, 50. 220, or 1200 MHz • Remote-mountabTe front panel
3 watt output from IWOS-FET power mcxiite and supplied 6-voll battery
(TH-22AT: approx. 3 watts, TH-42AT: approx. 2.5 watts), and 5 watt
output with optional PB-34 • Easy 12-volt operation with P6-2W or PG'3H
cable • Compact design: 2-3/16 x 4-5/8 x 1 in, • BuilHn DTMF keyboard with
monitor
Full ill0lx cross-band operation * CTCSS erfeotfsi/tfecDde built-in •
Alptia numeric display and message paging • Wide band receiver • 50
memory channels * Sliding keyboard cover and illuminated keypad
Cut Your Own Deal
TOOUf Ctl^JF^erS PRESCTT THE COMPlETtO COUPON AT THE IlME OF
PtPRCtUSTTO YOUR AUTHORIZED iCENWr^OO AMATEUR RADIO DEiy.ER H)R
TOUR DlSCOUMT. This coupon may be used ool)' for tne Kcf^wooa mode's usted
here, for tfie appropnatt discount indFcaifld. J\\& coupon is m\ QOOt for cs&h.
Qtrer good on^ at autriorized dealers.
To aulhorized Kenwood (^^^tf^rs: Indicate Ihe radio purchased ^nd discount
amount Send thJ^ coupon, abng wiLh a cop^ qI Lhe sal&s rec^eipi, to Kertvrood
Communic^lions Corporation. Antntion Summer Sale
HAJyg
ADDRESS
~l
Please check model purchased & discount
_TS-950SDX SlOOotf _™-733A S20off
.™-742A ^Ooft
m ^ VE
^ $50
_TS-&5CS'
_TS-450S"
_TS'&OS
_TM'241A
$ 50 Olf
$ 50 Oft
$ 50 o1f
$ 30 off
TH-22AT/42AT S20Dft
JH-7BA SaOoff
'mtiOrvmoutTwm
I
I CITY. STATE. ZIP^
PHONE
U
CALL SIGN
Coupon offer valid in USA onEy void where
prohibited This Eoupoti has rn) cash ^"alue COUPON
MUST BE FILLED OUT BY CUSTOMER ind
PRESENTED TO AN AUTHORIZED DEALER TO BE
V AL I D Not val i d wit h a ny ot h e r offers o r d i scou nts.
Coupon offer valid May 20 throDgh July 20, 1994
KENWOOD COMMUNICATIONS CORPORATION
Amateur Radio Products Group
P.O. Box 22745. 2201 E. Dominguez Street
Long Beach, California 90801-5745
eCopfffglt 1994 KEnwoocT Communications Corpcmtiofi
AH ngfrts rtservod
94AIUH3&I7
J