QRZ! Ham Radio 4/QRZ Ham Radio Callsign Database - Volume 4.iso/files/arrl/qst/qstdig01.93

Internet Message Format | 1994-11-20 | 38KB

From: [e-mail] (William E Van Horne)
Newsgroups: rec.radio.amateur.misc
Subject: Digest of Articles - QST Jan 1993 (Long - 38k)
Date: 1 Mar 1994 11:56:01 GMT
Organization: The Ohio State University
Lines: 746
Message-ID: <2kvagh$[e-mail]>
NNTP-Posting-Host: bottom.magnus.acs.ohio-state.edu

Starting with the January, 1993 issue, digests of articles published
in QST Magazine are being prepared, and will be posted on this
newsgroup.  They will appear approximately one per week through the
1993 issues and until they "catch up" with the current 1994 month.
Subsequent issues will be posted monthly, as published.

It is hoped that others will volunteer to post similar digests of the
other ham technical publications such as QEX, CQ, 73, COMMUNICATIONS
QUARTERLY, RTTY JOURNAL, et al.  Especially desirable would be digests
of publications in other countries, such as the RSGB RADIO COMMUNICA-
TIONS and ham magazines in Europe, Japan, Australia, and other countries
around the world.  We English speakers would especially enjoy them if
they were translated into our language, but they would also be valuable
additions to the world's knowledge if they were posted in the language
of origin.  Who knows?  Some bi-lingual ham somewhere might translate
them into English and re-post them.

Worldwide communications are getting better and better.  The time has
come to make the world's amateur press available to all hams throughout
the world!

The major value of digests or abstracts is to give readers sufficient
information to decide whether to obtain a copy of the full text.  If any
U.S. reader wants a copy of an article in QST, please inquire of other
hams in your own neighborhood.  Many have collections of back issues.
Anyone who is unsuccessful in finding a fellow ham with a collection
should try every library in the area, especially those at universities
and technical colleges.  If all else fails, a copy can be obtained from
the ARRL Technical Department, 225 Main St., Newington, CT 06111-1494
USA for a fee of $3.00 per copy.  Remember, it is both cheaper and
quicker to obtain one locally.

Readers in most other countries can obtain copies from their own
national ham organizations, sometimes translated into their own
languages.

For those who intend to build an archive from the following digests, the
first block of each article contains four items: Title, Author, Source,
and Abstract.  Ahead of the title is a two- or three-letter code to
indicate which kind of article it is; e.g. "TA" for Technical Article,
"HK" for Hints and Kinks, etc.  They are structured to be easily
captured by a computer program without human intervention.

-------------------------------CUT HERE---------------------------------

HAM DIGESTS -- QST, January, 1993
                               _________

COPYRIGHT NOTICE: Copyright to all the following material from QST
Magazine is held by the American Radio Relay League (ARRL), effective on
the date of issue.  Permission is granted for redistribution of the
following in its entirety, or in part, provided that this copyright
notice is not removed or altered and that proper attribution is made to
ARRL as publisher of QST, to the authors of the original articles, and
to W. E. "Van" Van Horne, W8UOF, author of this compilation.
                               _________

TECHNICAL ARTICLES (TA)

Title> TA:Slow-scan TV - It Isn't Expensive Any More!
Author> Langner, John - WB2OSZ
Source> QST Jan 1993, pp. 20-30
Abstract> Slow-Scan Television (SSTV) is described and its history
related.  Relatively inexpensive equipment is available to send and
receive SSTV according to standards now accepted by hams.  The author
offers an interface, in kit form, to link a computer with a transceiver
to exchange SSTV images using any of the currently popular modes.  It
includes both hardware and the necessary software.

Digest> Slow-scan TV is a name given to a mode of transmission used by
many hams to send single images to each other on the amateur bands,
primarily the HF bands.  In one sense, it is more akin to facsimile than
to television in that it requires a substantial amount of time to send
the image, such as a photograph or diagram.  The system requires: (1) a
source of the image in digital form, (2) the radio link, and (3) the
receiving equipment that can convert the signal to a picture on a TV
screen and/or some type of printer.

This article presents a basic description of slow-scan TV as practiced
by the Ham community.  It tells the history from the beginning in 1958,
when a group of amateurs developed a black and white system capable of
transmitting and receiving rather coarse monochrome pictures and
displaying them on surplus radar cathode-ray tubes.

Years of ham development culminated in the mid-1970's with a system
manufactured by Robot Research Company and called their Model 1200C Scan
Converter.  It was called that because it converted the electronic
signal transmitted on the ham bands with a bandwidth limited to 3000 Hz.
to the home-TV standard video signal so that it could be displayed on a
common color-TV set.  It provided a full-color image with 120 lines
vertical resolution transmitted in eight seconds, but the cost was $1300
for the scan-converter alone.

The author notes that many hams who are interested in operating SSTV
today are driven away with the belief that this mode is still very
expensive.  He shows that with the availability of computers in many, if
not most, hamshacks and the development of much lower cost interface
hardware, slow-scan TV is in the price range of a much larger segment of
the ham community.

Through the years a number of different SSTV modes have been developed,
to be set up in computer software.  They range from the original Robot
120 line black/white mode up to the highest resolution one now in use,
known as AVT 188.  It uses a 400-line RGB (for red, green, and blue) CRT
display scheme.

The author describes in considerable detail the various functions that
are required to transmit and receive the SSTV images.  At the
transmitting end, the image must be in digital form; either it is
obtained in that form by downloading it from a computer source, or it
must be developed by a TV camera, or optical scanner, plus a digitizer.
This will break the picture into pixels, comparable to the dots on a
newspaper photograph.  Then each pixel is encoded as an audio tone
between 1500 to 2300 Hz. and transmitted in sequence over conventional
ham radio gear.

At the receiving end, the audio tones must be decoded into color and
intensity values for each pixel and converted into a video signal for
display on a TV screen.  Most of the necessary digital processing can be
done by a conventional home computer with the addition of a plug-in
interface board.

The author describes an interface board and is offering it in kit form.
He calls it the Pasokon TV Interface.  The word is a Japanese-English
abbreviation for "personal computer".  The kit sells for $199.95 and
includes the necessary software for processing any of the popular SSTV
modes which utilize vertical resolution ranging from 120 to 400 lines.

The horizontal resolution is determined not by the transmitter, but
rather by the receiver, to fit the requirements of the display device.
Since the Pasokon is designed for use with an IBM-compatible computer
containing a VGA display, it uses 320 pixels per line for all modes.

Any hams who are already equipped with HF station and IBM-compatible
computer using 80286 or later CPU, at least 640 kilobytes of RAM and
VGA displays, can get started by simply adding the Pasokon plug-in
boards.  They will be able to transmit images they have created on their
own computers or obtained in computer form from other sources, and
receive any image that has been transmitted to them.

To be able to send photographs taken by themselves or captured from a TV
screen, they will need TV-cameras or scanners, and digitizers. The
article lists a number of commercially available video digitizers, the
prices of which vary with the speed at which one complete image can be
processed.  The fastest one, capable of capturing the real-time rate of
video programming, 30 frames per second, sells for approximately $2000.
At the other extreme, a kit is available for $89.95 that will process a
limited-resolution image with a limited number of different colors in
eight seconds.
                               _________


Title> TA:High-Performance, Single-Signal, Direct-Conversion Receiver
Author> Campbell, Rick - KK7B
Source> QST Jan 1993, pp. 32-48
Abstract> Described is an improved direct-conversion receiver that
offers single-signal performance.  It eliminates the audio image by
the phasing method of cancelation.

Digest> This same author wrote a similar article: "High-Performance
Direct-Conversion Receivers", in QST's August, 1992 issue.  That was a
construction article that described a DC receiver, called the R-1.  It
has been duplicated by many hams who have reported excellent
performance.

        The present article gives construction details of a similar
receiver, the R-2, that includes the added feature of "single-signal"
performance.  It overcomes the most important remaining shortcoming of
the earlier receiver compared with superheterodynes.  That is, it
eliminates the "audio image" inherent in the basic direct-conversion
process.  In that process there is no intermediate frequency (i.f.); the
local oscillator operates at signal frequency and converts the modulated
r.f. directly to audio.  So, when listening to a single-sideband signal,
for example, the oscillator is at the frequency of the suppressed
carrier and will convert to audio not only the desired SSB signal but
also any interference that may appear where the other side band would
be.  In contrast, a single-signal system like the one in this article
responds only to signals on one, selectable, side of the oscillator
frequency.

        The circuit used to perform this function is the familiar one
that was used years ago in "phasing-type" SSB transmitters.  This
principle requires splitting the r.f. input into two separate channels
with two mixers; the local oscillator signal to one mixer is shifted 90
degrees in phase from that to the other; the phase of the audio signal
in one channel is also shifted by 90 degrees and the outputs of the two
channels are combined in a summing circuit.  The result is that the
audio signals in one sideband add, and those in the other subtract to
near zero signal level.

        The article gives detailed construction parameters for operation
on amateur bands from 3.5 Mhz. to 222 Mhz. and has designed a two-sided
printed circuit board that contains all components except for those that
are frequency-specific.  The r.f. input circuits, including
pre-amplifiers recommended for bands above 7.3 Mhz., and local
oscillators, are mounted separately.

        The printed circuit board is available for $20.00 from Applied
Radio Science, P.O. Box 225, Houghton, MI 49931.  A set of etching
template and parts-overlay diagrams is available for an SASE from the
ARRL Technical Department.

        Mr. Campbell reports the results of tests that he made on a
40-meter model and compared them with measurements made on two
commercial superhets: a modern solid-state transceiver with 2.4 Khz.
i.f. filter and an old Collins 75S-3C with its mechanical filter.  He
discovered, to his surprise, that the suppression of the unwanted
sideband in the R-2 is actually the best of the three.

        A similar 40-meter version of the R-2 was tested at ARRL
Headquarters by Mark Wilson, AA2Z.  He reports having used it during the
CW Sweepstakes with excellent results.  He even stated that the lack of
AGC, which he expected to be an annoyance, was no problem to him.  His
final summary was: "This home-brew receiver holds its own, even under
demanding conditions....I like projects you can build and enjoy without
apologies.  This is one of those projects."
                               _________


Title> TA:Introducing METCON, A New Remote Control and Telemetry System
Author> Newland, Paul - AD7I
Source> QST Jan 1993, pp. 41-47
Abstract> Tucson Amateur Packet Radio (TAPR) is offering a control
package to provide telemetry and control signals through conventional
communication links, including radio.  Included are three types of input
modules for a variety of transducers.  Reliable verification procedures
prevent unauthorized persons from taking control.

Digest> This article describes a system developed by Tucson Amateur
Packet Radio and now being offered for sale in kit form.  It designed to
operate at a remote location connected to the home base via a
communications link which can be telephone, continuous radio link,
packet link, or any other convenient method of signal transmission.

The system performs two types of functions: (1) measurement and
telemetry, and (2) automatic control.  Measurements are made by means of
inputs from transducers and can represent temperature, power
consumption, liquid level, wind velocity, number of times a motor has
run over a time period, or any other of myriads of real-world variables.

METCON provides three basic ways that such variables can be represented:
(1) a static value, such as temperature or battery voltage; (2) rate
(pulses per time interval); and (3) total pulse count.

Automatic control is done by means of switch closures.  The basic METCON
board contains eight SPST relays with isolated contacts that can be used
to actuate a.c. or d.c. circuits up to 24 volts above or below ground
and with contact current not over .25 amps.

To facilitate the use of many different kinds of transducers, the
manufacturer provides three kinds of input modules.  The first of these
is a voltage- or temperature- to-frequency module.  It can be configured
for full scale input ranges of 0-1, 0-10, or 0-100 volts d.c. Its output
produces a continuous pulse train over the frequency range of 0-10 Khz.
directly proportional to input voltage.  In addition to accepting
voltage input, it also can measure temperature with an on-board
temperature-to-frequency transducer.  Jumpers in the module can be set
to configure conversion in either degrees Celcius or Fahrenheit.

Another module is an analog-to-digital converter.  This provides an
8-bit output for each of 8 analog inputs. The input voltage ranges can
be adjusted by means of jumpers and/or resistor substitutions for each
input, independently.

The third module offered is an elapsed-time pulser that generates a
pulse for each unit of time that its input is energized, from one pulse
per second adjustable down to one pulse for every two minutes.  By
totalizing these pulses, one can obtain the total running time of a
particular motor, for example.

As an example of a way the system can be used, the article describes a
monitoring system for a boat anchored remotely in a harbor. In the
owner's home would be a personal computer, a TNC, and a 2-meter
transceiver.  On the boat would be a 2-meter transceiver, a TNC, and a
METCON system with transducers and modules.  Under program control, or
on demand, the owner could check to be sure that the boat is not filling
with water, has not moved more than a specific distance from its
anchorage, has not been broken into, and the like.  Transducers proposed
are a liquid-level float for bilge water, a pulser totalizing the number
of times the bilge pump has run, entry switches on the hatch cover(s),
and the like.

METCON also provides an elaborate authentication procedure so that no
unauthorized person can take control of the system.  Even if a would-be
intruder should repeatedly record the owner's signals accessing the
monitor over the air, it would not be possible to derive the accessing
key.

Information and kits for METCON and the modules are available from
Tucson Amateur Packet Radio (TAPR), P.O. Box 12925, Tucson, AZ 85732,
phone [phone].
                               _________


Title> TA:A $5 Headset Mike
Author> Brede, Doug - W3AS/7
Source> QST Jan 1993, pp. 48-49
Abstract> Construction details for a simple, inexpensive microphone.

Digest> This is a construction article describing a very simple, small,
and light-weight mike made from an electret element available from Radio
Shack.  The author mounts the tiny element on one end of a 6-inch piece
of stiff wire and, on the other end, a spring-loaded battery clip.  He
attaches a length of RG-174 miniature coax cable to the mike and
encloses cable and support wire in a length of shrink tubing.

In operation, the spring clip is used to hold on to the support band of
a headset and the wire is bent to place the mike at a convenient
location in front of the user's mouth.  The user then can carry on QSO's
with both hands completely free and the mike always in position.

The tiny microphone element contains within it a preamplifier which
requires supply voltage between 1 and 10 volts at less than 1 milliamp.
The author's rig, like many modern ones, supplies d.c. voltage on one
pin of the microphone connector, so he does not need a separate battery.
If such voltage is not available, small penlite (size AAA) batteries
will supply the required power.  Battery life will be a year or more, in
most cases.  A wiring diagram is included.

The author reports that this simple and very inexpensive microphone is
not only very convenient to use, but also its audio quality is very
good.  In using it, he had no problems with r.f. feedback in his shack.
Using other mikes, he has had persistent problems due to the poor r.f.
grounds, which are the best that he can obtain at his location.

------------------------------------------------------------------------

PRODUCT REVIEW (PR)
     conductor: James W. Healy, NJ2L
                Sr. Asst. Technical Editor
                           _________

Title> PR:Ten-Tec Omni VI MF/HF Transceiver
Author> Healy, Rus - NJ2L
Source> QST Jan 1993,pp. 65-68
Abstract> Specification and performance review of the latest version of
Ten-Tec's Omni Transceiver.  New features are DSP, built-in keyer, dual
serial ports.  Reviewer calls it the "easiest to use" of all new
high-perfomance transceivers.

Digest> The Omni VI is the latest upgrade of the Omni line of
transceivers.  It has been specifically designed in accordance with the
opinions and recommendations of DXers and contesters.

Among the many new features that this model contains, one of the most
significant is Digital Signal Processing.   The DSP system built into
this rig duplicates many of the functions that are now being offered by
the outboard DSP packages that are coming into fairly wide use on the
ham bands.  Included are the automatic notch filters that eliminate all
heterodynes within a passband without reducing the fidelity of the
underlying audio signals.  Also provided are a wide selection of
band-pass filters for use on CW, FSK, and SSB.

A built-in keyer is provided, with front-panel speed control and
adjustable weighting.  Also included are: FSK mode with a fixed 170-Hz.
shift; separate receive antenna jack with a front panel selector button
and indicator; and a reset button to clear the RIT and XIT offset
without having to center the control knob.

Unique among available transceivers, the Omni VI provides two serial
ports.  One is a conventional RS-232 port that can be used for computer
control, or other accessory control.  The other port has a 1/8" jack
compatible with ICOM's CI-V interface.  Through both ports, it supports
the ICOM command set, hence ICOM software should also work.

A wide variety of optional filters, including one dedicated specifically
to FSK, are provided.  Also a voice synthesizer and ALC annunciator are
available for vision-impaired operators.

The Omni VI is not available with an automatic antenna tuner.  Also it
does not provide general coverage reception or a transmitted-audio
monitor.

Mr. Healy states that Ten-Tec is known for its excellent full-break-in
(QSK) keying, and the Omni VI carries on this tradition. It operates in
QSK mode all the time; the operator selects only the rate at which the
receiver recovers; rapid for break-in, slow for semi break-in.

The reviewer's opinion is that the Omni VI is exceptionally well
designed for convenient and efficient control under demanding conditions
in DX pileups or in rapid-fire contest operation.  He says flatly that
"Of all the truly high-performance radios currently on the market, the
Omni VI is the easiest to use....Ten-Tec's approach to designing and
testing this radio shows their commitment to demanding users."
                               _________


Title> PR:PacComm PacTOR Multimode Controller
Author> Ford, Steve - WB8IMY
Source> QST Jan 1993, pp. 68-70
Abstract> PacComm's newest TNC, designed for PacTOR; also operates in
AMTOR, RTTY, CW.  Reviewer finds performance superior in PacTOR,
adequate in other modes.

Digest>This is a review of a new PacComm TNC specifically designed
for PacTOR use.  In spite of that fact, it is a fully-versatile
multimode TNC and operates well also in the AMTOR, RTTY, and CW modes.
As an extra-cost option, it can also be provided with HF packet mode.

The reviewer's opinion is that the performance on PacTOR is exceptional.
One unique feature is automatic selection of PacTOR or AMTOR.  When one
calls CQ on either mode, an answer may be received either by a PacTOR or
an AMTOR ARQ station.  If the reply to a PacTOR CQ comes back in AMTOR
ARQ, the PacComm controller automatically switches to AMTOR!

The reviewer found AMTOR operation to be "relatively smooth, aside from
a few quirks".  However, he rates performance on RTTY "only average".

The one item about which the reviewer is most critical is the
deficiencies of the Owner's Manual.  He feels that it gives a good
discussion of theory and "fairly clear" set-up instructions, but falls
down badly on the details of how to use the various modes.  It seems to
be written more for hams who already are well experienced with digital
modes.  His summary opinion is: "The unit is a good value for the money.
Its PacTOR and AMTOR performance is excellent, and you get a CW keyer
and RTTY operation in the bargain".
                               _________


Title> PR:K1EA Software Digital Voice Processor
Author> Healy, Rus - NJ2L
Source> QST Jan 1993, pp. 71-72
Abstract> A plug-in card for IBM-compatibles.  Digitizes, records, and
plays back audio.  Especially useful in contests.

Digest> The reviewed processor is a new piece of hardware being
manufactured by Ken Wolff, K1EA, who is the author of the CT Contest
Software.  Its concept is simple: It takes audio input from a radio or a
microphone, digitizes it, and stores it on your computer's hard disk. On
demand, it plays it back, driving a transmitter or headphone, or both.

The unit is specfically designed to work with the manufacturer's CT
software in contest operations.  It allows the operator to record
libraries of CQ, QRZ, call sign, contest exchanges, and many other kinds
of messages for automatic playback during the contest period.  In
addition, it can record audio in increments from 5 seconds to 30 seconds
so that if one misses a call sign during the "heat of battle", it can be
instantly replayed it while simultaneously the device is continuing to
record what is coming in through the radio!

All this is being done with very high fidelity.  The digital sampling is
being done at 9600 samples per second with a 12-bit resolution in the
A/D converter.  The reviewer reports that replaying the audio after it
has been digitized, recorded, and restored to audio through a D/A
converter, the result is indistinguishable from the live audio!

The reviewer's final summary expresses the opinion that: "If you're
serious about voice contesting, you should consider adding a DVP to your
station".

------------------------------------------------------------------------

HINTS AND KINKS (HK)
     conductor: David Newkirk, WJ1Z
                Sr. Asst. Technical Editor
                               _________


Title> HK:1-Watt In, 30-Watts Out With Power MOSFETs at 80-Meters
Author> Wyckoff, Jim - AA3X
Source> QST Jan 1993, pp. 50-51
Abstract> Construction article.  Build a power amplifier for 80-meters
using two common MOSFETs.

Digest> Mr. Wyckoff shows a wiring diagram and a photograph of a class-B
linear amplifier that he built using inexpensive IRF-511 power MOSFETs.
It is a push-pull amplifier designed for the 3.5-4.0 MHz. band and uses
an adjustable bias circuit to balance the operating characteristics of
the two transistors.

The author reports that the amplifier performs well and its stability is
excellent.  He does not advise attempting to operate the amplifier on
the higher bands since the output power diminishes as the frequency
increases.   The amplifier delivers full 30-watts output with 1-watt
drive on 80-meters, but on 10-meters its output is only 10-watts.
                               _________


Title> HK:A Light-Operated Switch for Solar Panels
Author> Harbison, Lawrence - N7HRN
Source> QST Jan 1993, p. 51
Abstract> Construction article.  Build a light-operated controller to
open-circuit a solar panel used to charge batteries.  Protects batteries
from discharge.

Digest> The author lives in sunny Arizona and had available a 2.0-amp
solar panel that he wanted to use as a power source to charge a deep-
cycle battery.  In such use, it is necessary to protect the battery from
discharge when the sun goes down.

The simplest solution is to put a diode in the lead from the solar cells
to the battery, but this sacrifices some 3- to 6-percent of the charge
capacity due to the voltage drop.  As a result, he designed a circuit
that uses a cadmium-sulphide photoresistor to detect when the light
becomes dim and opens a relay, isolating the battery.

A wiring diagram and photographs are included with the article.
                               _________


Title> HK:Curing RFI in the Ham IV Control Unit
Author> Pataki, George - WB2AQC
Source>QST Jan 1993, p. 51
Abstract> Using by-pass capacitors to eliminate r.f. interference.

        Mr. Pataki's ham transmitter has a 400-watt output and, when
his beam was directed toward his house, the modulation on his signal
caused the meter on the rotator controller to fluctuate.  He found
the effect annoying but was able to correct it by installing by-pass
capacitors from each end of the rotator's direction-sensing pot to
ground.  He used .047 mfd. capacitors but indicates that any value from
about .01 to .1 mfd. should work well.  The capacitors should have a
working-voltage rating of at least 25-volts d.c.
                               _________

Title> HK:Take Notes With a Camcorder
Author> Jones, Clark - N7RPQ
Source>QST Jan 1993, p. 52
Abstract> Use a camcorder to record, in video and audio descriptions,
details of work done on electronic gear.

Digest> The author reports his success in recording on a camcorder his
experiences working on electronic gear.  He mounts the camera in a fixed
position having a clear view of the work surface and dictates a
commentary as he goes.  When the job is completed, he puts a label on
the tape identifying the gear.

Although he uses standard, not high-quality tapes, he cautions against
using inferior tapes that might deteriorate in time since he expects to
keep them for long periods.
------------------------------------------------------------------------

TECHNICAL CORRESPONDENCE (TC)
     Conductor: Paul Pagel, N1FB
                Associate Technical Editor
                               _________


Title> TA:Touch-Control-Lamp RFI
Author> Wiley, James B. - KL7CC
Source> QST Jan 1993, pp. 53-54
Abstract> Describes RFI from "touch-control" lamps.  They contain
oscillators at 150-200 KHz. with no filtering.  Recommends ways to
locate offending lamps and what to do about them.

Digest> This letter regards a relatively new type of RFI problem many
hams are now experiencing.  It usually appears in the form of a
broadband, slowly drifting, a.c.-modulated signal.  The sources are
touch-controlled lamps.  They operate on the capacitance-relay
principle; each has a sensing contact that one touches to turn the light
on or off.  It is connected to a tuned circuit that controls an
oscillator.  Touching it adds capacitance which detunes it, resulting in
a drop in the signal level to a built-in detector that then open or
closes a relay, or in some cases adjusts brightness level up or down.

Most of these operate at frequencies in the 150 to 200 Khz. region, but
their outputs are typically very rich in harmonics. Interference from
such devices usually appears as broad-band, a.c.-modulated signals,
often appearing every 50 to 200 Khz. across the band.  They typically
drift slowly and consequently come and go.

This kind of interference sometimes can create problems as far as 1500
feet from the source.  In many cases, the interference is two-way; a
strong ham signal may actuate the lamp.  The author notes a case in
which he discovered the source of interference as a result of operating
his high-power station on CW.  The neighbor's offending lamp flashed on
and off with the code!

To locate the source of such interfering signals, the author suggests
the use of a portable short-wave receiver with a loop antenna. Even
approaching the service entrance wires of a home containing an offending
device is usually enough to get a noticeable signal.  If the owner will
permit entrance to his premises, the same radio can generally be used to
point out the offending lamp.

He reports that it is usually not possible to eliminate the interference
through the use of filters or other conventional RFI isolating
techniques, because of the fact that the exposed contact plate itself
acts like an antenna.  FCC regulations, Part 15, prohibit consumer
devices from interfering with communication services, but usually it
takes considerable diplomacy to convince homeowners to stop using a
device that they have bought and paid for.  The ARRL publishes a variety
of materials and guides. Anyone suffering from such interference is
strongly advised to obtain the ARRL "RFI Package".  It can be obtained
by sending a 9 x 12 inch SASE with $0.98 postage to the Technical
Department Secretary, ARRL, 225 Main Street, Newington, CT 06111.

------------------------------------------------------------------------

FEEDBACK (FB)

Title> FB/TC:Dipoles Above Real Earth, QST Nov 1992, p. 68
Author>Michaels, Charles - W7XC
Source> QST Jan 1993, p. 54
Abstract> Error in a mathematical statement.

Digest> There is an error in the sentence "...to the feed point by a
factor 1/sin2L, but..."  It should have read: "...to the feed point by a
factor 1/sin^2L, but...", where "sin^2" means sine-squared.
                               _________


Title> FB/TA:A Dual Radio Speaker, QST Nov 1992, pp. 56-58
Authors> Ramhorst, Neil - KL7JGS and Cady, Fred - KE7X
Source> QST Jan 1993, p. 54
Abstract> Error in wiring diagram.

Digest> The wiring diagram showing the two-pole, 3-position switch is in
error.  The correct wiring is shown in this issue (January, 1993), p.
54.

------------------------------------------------------------------------

GENERAL INTEREST ARTICLES (GI)
                               _________

Title> GI:The Beat of a Different Drum:
Author> Booth, Rick - KM1G
Source> QST Jan 1993, p. 31
Abstract> Biography of Cop MacDonald, originator of ham SSTV.

Digest> Cop MacDonald, ex-W9OLS, who is now VY2CM, originated amateur
Slow-Scan TV (SSTV) in about 1953.  At that time he was in engineering
school and learned that Bell Laboratories was working on a way to send
signatures over telephone lines.  The method used was a scanner with a
scan-rate slow enough that the signal frequency did not exceed 3 KHz.
Mr. Macdonald realized that the same scheme could be used by hams to
send many different kinds of images over HF.

His first experiments used an oscilloscope with a phosphor that
had a persistence of some 7- or 8-seconds.  Hence, he designed a system
that would scan as much area as it could reach in 6- or 8-seconds
without exceeding the 3.0 KHz. frequency limit.

His first system used an AM subcarrier, with a 20-Hz. horizontal scan
rate and a 6-second frame repetition rate.  After a year or more of
experiments, he changed to FM with a 15-Hz. horizontal rate and an
8-second frame scan.

Other hams heard about his experiments and joined in, but it was not
until 1958 that QST published a comprehensive article on the new mode.
Meantime, Mr. MacDonald was enjoying a successful career in electronic
engineering and became the director of research for a company.  At that
point, he decided upon a change of life style and took a back-packing
trip around the world with his wife and daughter.  Since then, he has
moved to Canada and pursued other interests, including ecology, energy
conservation, and meditation.
                               _________


Title> GI:Excellence in Recruiting
Author> White, Rosalie - WA1STO
Source> QST Jan 1993, pp. 55-56
Abstract> How to interest newcomers to ham radio.

Digest> In this article, Ms. White discusses ways of interesting people
of all ages in amateur radio.  In 1992, the ARRL established a yearly
award to be given to a person most deserving of recognition for their
ability to attract "recruits" to the hobby.
                               _________


Title> GI:Tall Ships Pose a Tall Order for Boston Hams
Author> Booth, Rick, KM1G
Source> QST Jan 1993, pp. 73-75
Abstract> Boston hams organize activities around the "Tall Ships"
gathering.

Digest> In July, 1992, some 7-million people went to Boston to see the
"Tall Ships", the square-rigged sailing vessels that gathered in Boston
harbor to celebrate the 500th anniversary of Columbus' first voyage.
Boston hams offered their services and helped the Boston Emergency
Medical Service (EMS) care for the mass of visitors.  This is the story
of their experiences.
                               _________


Title> GI:A Good Day at Effingham
Author> Johnson, Tom - N4TJ
Source> QST Jan 1993, pp. 76, 78
Abstract> Fiction.

Digest> This is a fictional tale about a ham in the non-existent town of
Effingham, South Carolina who was also a news reporter.  It involved a
fire that started in an outhouse behind the county court house.  Rumors
of the fire spread, and grew, rapidly.  As the stories spread, they
became more exaggerated, which in turn caused them to be spread farther.
The end result was that they reached not only the state capital but also
to Washington, D.C., and there descended upon sleepy Effingham 28 fire
engines, 596 National Guardsmen, and helicopters carrying advanced
elements of the 82nd Airborne Division.
                               _________


Title> GI:Maritime Mobile, Love Boat Style
Author> Tinley, Hugh - K0GHK
Source> QST Jan 1993, pp. 79, 81
Abstract> Operating maritime mobile on a cruise ship.

Digest> Mr. Tinley tells the story of his Caribbean cruise aboard a ship
of Greek registry.  He found that, with the help of the ARRL, he had no
difficulty getting a Greek license to operate ham radio aboard the ship,
and was allowed to set up his rig on the sundeck, between the bar
and the swimming pool!  His rig put out 10-watts on 10-meters, and he
had an antenna on a fishing pole.  With this, he operated for six days,
during daylight hours.  After sundown, 10-meter propagation dropped off
and he was "forced" to pursue other activities on the ship during the
evenings.
                               _________

Title> GI:Life After Death: A New Beginning
Author> Wadsworth, Nat - WK1X as told to: Steele, Don - W1NFG
Source>QST Jan 1993, pp. 77-78
Abstract> A near-death experience.  Recovery was aided by ham radio.

Digest> Nat Wadsworth, WK1X experienced cardiac arrest and suffered
brain damage when his circulation stopped for 12-minutes.  Emergency aid
restored his heart and he lived, but was greatly impaired both mentally
and physically.  For a time, his memory was completely gone.  His first
recollections began when his wife told the physician, in Nat's presence,
that he had been a ham operator.  Little by little, his recollection of
radio operation and Morse code came back.  His recovery was accelerated
when he obtained a transceiver and returned to the air.  He is
continuing to improve and his doctors credit ham radio for much of his
progress.
                               _________


Title> GI:30-Years Between Novice Roundups
Author> Luetzelschwab, Carl - K9LA
Source> QST Jan 1993, pp. 80-81
Abstract> Ham radio nostalgia.

Digest> The author became a ham in September, 1961, when he was entering
the ninth grade in school.  He relates his experiences in getting a
station on the air and operating in the ARRL Novice Roundup competition
in February, 1962.

In January, 1992, he decided to repeat the experience using gear
identical to that he had used 30-years earlier.  He was able to buy an
old DX-20 transmitter and NC-60 receiver, two 40-meter crystals that he
could triple and also use on 15-meters, and put up an inverted vee
antenna at 25-feet height.  He enjoyed the experience thoroughly, but
admits that his score of 18 stations in 13 sections was not up to his
performance 30-years earlier, when he worked 42 stations in 18 sections.
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