Digest of Articles - QST Oct 95 (Long - 49k)

Digest of Articles - QST Oct 95 (Long - 49k)

Post by W. E. Van Hor » Tue, 28 Nov 1995 04:00:00

Following are digests of articles printed in the October, 1995 issue of
QST.  Such digests are being prepared for each issue of QST, and posted
periodically.  They are archived, beginning with the January, 1993
issue, and available by ftp from:
(USA) oak.oakland.edu/pub3/hamradio/arrl/infoserver/digests
and
(Europe) ftp.funet.fi/pub/ham/arrl/infoserver/digests

It is hoped that other hams 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.

The major value of digests 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 national
ham organizations, sometimes translated into their own languages.
-------------------------------CUT HERE---------------------------------

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.
                              _________

                          QST October, 1995
                          TABLE OF CONTENTS

        (line numbers indicated - counting from CUT HERE line)

TECHNICAL ARTICLES (TA)

TA1:The Offset Multiband Trapless Antenna (OMTA)                      71
TA2:Spectacular 1995 Transatlantic Sporadic-E Season                 126
TA3:Hot-Rod Your ICOM IC-725 - Series Transceiver  -  Part 2         165
TA4:Twisted-Pair Controls Switchable, Remote Loading Network         232
TA5:A Patch Antenna for the Global Positioning System                271

PRODUCT REVIEW (PR)

PR1:QST Compares:GPS-Compatible TNCs                                 319
PR2:QST Compares:Antenna-Modeling Software                           383

TECHNICAL CORRESPONDENCE (TC)

TC1:More On Selective Calling Systems and Repeaters                  496

HINTS & KINKS (HK)

HK1:The Revisited WD0O Timer at K6TGA                                531
HK2:Simple Timer Counts Up to 2-1/2 Hours                            548
HK3:Refelctive Tape for Easier Equipment Retrieval                   564
HK4:Checking the Performance of a Questionable Beam Antenna          576
HK5:Installing Ground Rods in Heavy Clay                             591
HK6:"Super" Glue Cures Transformer Buzz                              611

FEEDBACK (FB)

FB1:"Transmission Line Characteristic Impedance and Losses",         628
        QST Aug 95
FB2:"Bring 'Em Back Alive", QST Aug 95                               642

NEW HAM COMPANION (NHC)

NHC1:The Way We Were: Amateur Radio in the '50s                      671
NHC2:VHF/UHF Mobile in a Late-Model Corvette                         693
NHC3:The Doctor is IN                                                722
NHC4:Build Your Own 2-Meter Beam!                                    739
NHC5:A Townhouse Dipole                                              775
NHC6:Outerspace and ***space: Following Mir-18 From the            792
        Dominican Republic

GENERAL INTEREST ARTICLES (GI)

GI1:The 1995 Special Olympics World Games                            812
GI2:20 Years of ARRL DX Contesting From the Foot of the              831
        Swiss Alps
GI3:Propagation Pioneers: The ARRL - Bureau of Standards             853
        Experiment
GI4:Heroes Under Siege                                               915
------------------------------------------------------------------------

TECHNICAL ARTICLES (TA)

Title>TA1:The Offset Multiband Trapless Antenna (OMTA)
Author>Wilson, Robert - AL7KK
Source>QST Oct 95, pp. 30-32
Abstract>Describes a vertical antenna with 3 radiators: 1/4-wavelength
on 40-meters, and 1/2 wave on two higher bands.  Only the 40-meter
element is driven; the others are e***d parasitically.

Digest>AL7KK's antenna design is made up of three vertical aluminum-
tubing elements for three bands: either 40-, 20-, and 15-, or 40-, 20-,
and 17-meters.  They are erected close together, somewhat like the three
vertical members of a triangular tower, about 8-inches (20-cm.) on each
side.  They are held in place by four triangular spacers made from
1/2-inch (13-mm.) thick plastic carving boards.  At the base, three
floor flanges are fastened to a base plate, made of either wood or
carving board material.  A pipe adapter, that makes a mechanical
transition from the***thread of the flange to a compression fit on a
short length of PVC pipe, is screwed into each.  The tubing forms a base
insulator and the elements are fastened inside it with machine screws.
The assembly is guyed using three lengths of nylon rope fastened near
the top of the shortest element.

Only the 40-meter element is directly driven.  The other two are
electrically isolated and obtain drive through inductive coupling from
the driven element.

The 40-meter element is a quarter-wave monopole with four quarter-wave
radial wires strung along, or underneath, the ground.  The feed
arrangement is unusual; power is applied not at the base junction
between the radiator and radials, but instead, at a point 14-feet,
9-inches (4.50-m.) up from the base.  At that point, the element is cut
and separated by about an inch (25-mm.), inside a piece of PVC tubing
used as an insulator.  The shield braid of the coax is attached to the
lower piece, and the center conductor to the upper piece, of the
element.  At the base, the element is directly connected to the four
radials.

The 40-meter element is 36-feet (11.0-m.) long, in the author's case,
but must be tuned to exact resonance through pruning to a length
dependent upon the immediate surroundings.  AL7KK recommends that
pruning be done in 3-inch (76-mm.) increments.  His dimensions for the
higher-frequency elements are as follows: 20-meters: 33-feet, 2-inches
(10.11-m.); 17-meters: 26-feet, 1-inch (7.94-m.); 15-meters: 22-feet,
5-inches (6.70-m.).  All act as half-wavelength dipoles.  The author
assembled all his elements using 12-foot (3.65-m.) stock lengths of
tubing, spliced together with 8-inch (20-cm.) lengths of smaller
diameter tubing slipped inside and held in place with screws.

The combination of the offset feed to the driven element and the
inductive feed to the other elements provides a 50-ohm load that is
remarkably flat across all three bands.  The end result is a very
effective multi-band antenna that also makes a neat and attractive
appearance.
                               _________

Title>TA2:Spectacular 1995 Transatlantic Sporadic-E Season
Author>Pocock, Emil - W3EP
Source>QST Oct 95, pp. 33-37
Abstract>A systematic study of transatlantic sporadic-E propagation
during June-July, 1995.

Digest>Sporadic-E propagation is caused by clouds of ionized air that
intermittently form in the E-layer of the upper atmosphere, and reflect
radio waves at HF and VHF frequencies.  Unlike normal F-layer
propagation, these ion clouds are not strongly correlated with sunspot
activity.  Their appearances in time and space are almost completely
random, except they are most numerous around the summer solstice; in
June and July in the Northern Hemisphere.

Mr. Pocock - W3EP, who is the conductor of the regular QST department:
"The World Above 50-MHz", has been making detailed studies of amateur
sporadic-E communication for 15-years, or more.  The successful trans-
Atlantic communications that occurred during the summer season of 1995
represented the greatest number of contacts and the greatest distances
registered so far.

The normal limit to the distance covered by sporadic-E propagation in a
single hop is about 1430-miles (2300-km.)  Many of the QSOs registered
this year between North America and Europe spanned such a distance that
they clearly required four hops.  Many of these were from Eastern USA to
Eastern Europe, or Mid-Western USA to Western Europe.

Within the last few years, 6-meter DX contacts by this means of
propagation have increased greatly.  Much of the reason is that the band
is open to amateurs in many countries where it was previously forbidden.
Also, more high-power stations with large antennas have been coming on
the air.  It is not possible, yet, to determine whether the explosion of
activity during this year's peak season was due only to those causes, or
whether there was some phenomenon occurring in the atmosphere that made
this season so much more active than ever before.  Only continuing
studies in future years will begin to sort out the different factors.
                               _________

Title>TA3:Hot-Rod Your ICOM IC-725-Series Transceiver - Part 2
Author>Vermasvuori, Jukka - OH2GF
Source>QST Oct 95, pp. 38-41
Abstract>Describes modifications and additions to the IC-725 to overcome
shortcomings described in Part 1 of this article.

Digest>Part 1 of this article, in QST Sep 95, described OH2GF's findings
of performance shortcomings in his ICOM IC-725.  Among the factors that
he found most deficient in receiving were the Automatic Gain Control
(AGC), the wide apparent bandwidth of strong signals, and the automatic
level control (ALC); in transmitting, the lack of r.f. speech
processing.  In this article he describes the design and construction of
additions and/or modifications to make the rig perform the way a modern
transceiver should.  Each modification or addition is illustrated by a
schematic diagram and parts list.

The first is a simple "hang" AGC system.  This kind of AGC differs in
the following way.  When a standard AGC circuit receives an incoming
signal, it generates a proportional control voltage; after the signal
ceases, the control voltage gradually decays to the no-signal level.  In
the "hang" type, the control voltage responds to the onset of the signal
in the same way, but holds constant for a preset length of time, then
quickly drops to the no-signal level.

The wide apparent bandwidth is an effect that is most annoying when one
is receiving weak signals through a continuous line noise.  Like almost
all modern transceivers, the IC-725 has a noise limiter that is quite
effective in reducing pulse-type line noises.  However, if a strong
signal appears outside the i.f. bandwidth but within a few KHz. of the
desired signal, often the line noise is perceived to be surging to high
values in sync with the modulation of the unheard strong adjacent
signal.

This effect is caused by the fact that the filter in the first i.f. is
15-KHz. wide, to allow for reception of wide-band FM.  But the signals
fed to the noise-blanker circuit are derived from the first i.f., so a
strong signal even 5-KHz. away from the desired one, in effect
deenergizes the blanker.  Since OH2GF did not intend to listen to FM, he
replaced the "roofing" filter with a narrower one.  The one he selected
is a replacement part available from ICOM, their Part No. FL-116.

ALC in the transmitter is essentially the same function as AGC in the
receiver.  The ALC system in the IC-725, as manufactured, contains
certain time constants that cause unwanted phase shift resulting in
audio distortion.  The author improved the situation by changing certain
resistor and capacitor values, which he describes in detail.

In his final modification, he overcame the serious lack in the IC-725 of
a speech processor.  Modern information theory shows that the human
voice is a very inefficient "code" for transmitting information.  When
raw, unprocessed speech is used to modulate an SSB transmitter, the
ratio of peak-envelope power (PEP) to average power is some 15-dB.;
hence, when one is transmitting SSB at 100-watts PEP, the average output
power is 3.2-watts!  By clipping the audio 20-dB., one can raise the
ratio by about 6-dB., four times the power.  Then the average power
output is 12.8-watts, a very significant increase although still far
below the level of CW or digital modes.  Accordingly, Mr. Vermasvuori
designed and built an r.f. speech clipper on a small circuit board and
installed it in the rig.

Although his modifications were designed and built for the IC-725, there
are few modern transceivers that would not benefit from one or more
similar modifications.  As he stated: "...the fundamental radio
performance of even our best transceivers (is) poorer than it should
be".
                               _________

Title>TA4:Twisted-Pair Controls Switchable, Remote Loading Network
Author>Lee, Mitchell - KB6FPW
Source>QST Oct 95, pp. 42-43
Abstract>Construction details of an antenna with remotely-controlled
switchable loading network for tuning to several bands.

Digest>In this article, KB6FPW describes the antenna that he uses to
operate on the bands from 160- to 30-meters.  It is an inverted "L" with
essentially no feed line.  The single conductor begins at the output
terminal of his antenna tuner inside the shack, passes out via a
feed-through insulator to the outside, and upward to the base of a
20-foot (6-m.) steel TV mast on the peak of his roof.  At the top of the
mast is a plastic housing that contains loading coils and a remotely-
activated switch to select various taps on the coils.  From there, the
antenna continues as a horizontal wire, 33-feet (10-m.) long, to an
elevated support.

The remotely-activated switch is a Guardian IR-705-12P-12D Rotomite
stepper relay.  It contains twelve contacts selected by a wiper that
indexes ahead one position each time the coil current is pulsed.  Since
the author has no indicator in his shack showing its position at any one
time, he wired a beeper to be activated by the twelfth switch position.
In changing settings, he pulses the switch until the beeper sounds, thus
"zeroing" the switch, then counts the number of times that he presses
the activating button to select any particular position.

To run the control system, he needs three leads carrying 12-volts d.c.
to the top of the mast.  He uses the mast and the antenna wire for one
of the conductors, and runs a single twisted pair up the inside of the
tubing for the other two.  From the base of the mast down to the shack,
the twisted pair is run together with the antenna wire.

He uses two loading coils, wired in series, with taps.  One has
100-microhenry inductance, and the other 7.  Both coils are used when
tuning 160-meters; for 80-meters, only the 7-microhenry coil is in the
circuit; for 40- and 30-meters, intermediate taps are used.
                               _________

Title>TA5:A Patch Antenna for the Global Positioning System
Author>Ward, Harold R. - W1GE
Source>QST Oct 95, pp. 44-45
Abstract>Construction details of a simple antenna for GPS signals.

Digest>The Global Positioning System (GPS) is coming into use by
amateurs for various purposes, including the Automatic Packet Reporting
System (APRS) which was described in QST Jul 93 by WA1LOU, and in other
articles.  Also, the Product Review of this issue contains relevant
material.

W1GE describes a small and unobtrusive antenna that he built and
attached to the roof of his car to receive GPS signals while it is
moving.  It is a simple device that forms a circularly-polarized
antenna.

The antenna is made of two small pieces of sheet aluminum, or plates,
separated a fixed distance by nylon spacers, and held onto the roof by
four magnets.  A length of RG-58 comprises the feedline to the inside of
the car.

The two plates are known as the groundplane and the patch.  The
dimensions of the latter are very critical; those of the groundplane
considerably less so.  Five holes are drilled through both plates; four
at the corners for the supporting bolts, and one precisely located for
attaching the center conductor of the feedline.  Its location causes the
antenna to exhibit right-hand circular polarization.

As assembled, the patch is held to the ground plane with No. 8 nylon
bolts and nuts, and the separation between plates is determined by the
thicknesses of three No. 8 nylon washers stacked on each of the bolts.
The shield braid of the feedline is connected to the underneath side of
the groundplane and the center conductor is fed upward through both
holes to the top of the patch where the conductor is attached.

Four magnets, at the four corners of the groundplane, hold the antenna
to the roof of a vehicle.  They must be thick enough to raise the
groundplane sufficiently to allow the cable to pass between it and the
car roof to reach the feedpoint.  To avoid scratching the paint on the
roof, the magnets are coated with silicone tub calk.
------------------------------------------------------------------------

PRODUCT REVIEW (PR)
        Conductor: Mark Wilson - AA2Z
                   Editor, QST
                               _________

Title>PR1:QST Compares: GPS-Compatible TNCs
Author>Ford, Steve - WB8IMY
Source>QST Oct 95, pp. 68-71
Abstract>TNCs compatible with GPS signals can be used to send packet
reports of the precise location of vehicles automatically.  This article
reviews such units made by AEA, Kantronics, and PacComm.

Digest>The Global Positioning System (GPS) is the satellite system that
is now available for private use that gives users their exact locations
anywhere on the face of the earth, to an accuracy of 200-feet (60-m.),
or better. Recently, the Automatic Packet Reporting System (APRS) has
been developed by amateurs.  It makes it possible for a vehicle,
equipped with an amateur packet transmitter, a GPS receiver, and a TNC,
to send automatically, by packet, frequent reports of its location.
This review describes several TNCs that include the GPS function along
with normal packet functions.

AEA PK-12

The first unit tested was the AEA PK-12 equipped with Version 7.1
firmware.  It is a 1200-baud, full-featured packet TNC, including
mailbox and node functions as well as KISS and HOST modes along with the
capability of handling GPS data.

The unit comes with all necessary software, and also an excellent and
comprehensive manual that contains a veritable packet tutorial.  When
used with GPS, it does not even need a computer; it will automatically
transmit packets at preset intervals.

The manufacturer's list price is $129.

Kantronics KPC-3

Next reviewed was the Kantronics KPC-3 with Version 6.0 firmware.  This
unit was reviewed for general packet use in QST Dec 93.  Its power
requirements are so small that it can be powered by a standard 9-volt
battery.

To initiate GPS operation, it is necessary to give it a command from a
computer, but then it can be disconnected, placed in a vehicle, and
operated with no further computer connection.  The KPC-3 is a
full-featured packet TNC and comes with all necessary software,
including a copy of PacTerm, HostMaster, plus everything necessary to
monitor WEFAX weather maps and G-TOR conversations.

Its suggested list price is $119.95.

PacComm TINY-2 MK-2

The TINY-2 MK-2 is not only a TNC, but it also includes a built-in GPS
receiver.  Like the Kantronics KPC-3, the TINY-2 MK-2 was reviewed in
QST Dec 93, but at that time did not have the built-in receiver.

The current model includes a round magnet-backed patch antenna,
2-3/8-inches (60-mm.) in diameter, and also a plug-in power supply
module for use on a.c. power.  The one major drawback of this unit is
the inadequate operating manual.  The 1993 review strongly criticized
that lack, and the present manual is even worse, since the GPS and APRS
information is especially inadequate.

The manufacturer's list price is $629.
                               _________

Title>PR2:QST Compares: Antenna-Modeling Software
Author>Straw, R. Dean - N6BV
Source>QST Oct 95, pp. 72-74
Abstract>Describes antenna analysis software based on the Numerical
Electromagnetics Code (NEC) offered by Roy Lewallen - W7EL and Brian
Beezley - K6STI.

Digest>A number of years ago, a U.S. Government agency developed a
mainframe computer program, the Numerical Electromagnetics Code (NEC),
that would calculate antenna performance.  A few years later, a
simplified version for personal computers was created, called Mininec.
Now, with modern PCs equalling, or even surpassing, the power of
former mainframes, the full NEC has been adapted to operation on
machines using Microsoft DOS or Windows operating systems.

The original Mininec and NEC programs are awkward to use, so two
amateurs: Roy Lewallen - W7EL, and Brian Beezley - K6STI, developed
versions, first of Mininec and now of NEC, featuring clarified and
simplified controls so that any ham can readily learn to use them.

W7EL called his Mininec version "Elnec", and it became popular with many
hams.  Now, he has issued his NEC version, that he calls "Eznec", using
mostly the same commands and screen displays previously used in Elnec,
but with expanded capabilities.

To calculate the performance of an antenna, one must "model" the antenna
in the computer.  This means the entering into the computer the
measurements of each wire in three coordinates: x, y, and z.  Once the
wires are all specified, the locations of one or more feedpoints is
entered; any "loads", such as loading coils, traps, or resistors, can be
described; the type of ground specified; and the operating frequency
selected.  Then the computer will calculate essentially all operating
variables and will plot radiation patterns in both azimuth and
elevation.  The azimuth pattern can be calculated at any elevation
angle.  Current flow at every point in the antenna can be listed, as
well as input impedance and SWR at the feed point(s).

Mininec was, and continues to be, a highly useful program for many
applications.  However, it has some limitations that make it unusable
for certain types of antennas.  For example, it cannot be used to
analyze open-wire transmission lines which are integral parts of certain
kinds of antennas, such as log-periodic dipole arrays (LPDAs).  Also, it
has difficulties with sharp corners, such as those in cubical quads and
rhombics.  Furthermore, horizontal arrays within 0.2-wavelengths of
ground cannot be analyzed properly.  NEC overcomes most of these
difficulties, is more accurate, and often is faster, as well.

Specifying the wire dimensions is a tedious chore and, once it is
completed, it is almost a necessity to look at a diagram showing the
antenna as specified.  Often a user will find that a mistake of one
number makes a wire to go off at an odd angle.  The "View Antenna"
command in Eznec provides an isometric view that includes all the wires,
loads, and sources.  It can also show a graphic representation of the
current flow in each wire, as well as an overlay of the azimuth and/or
elevation plots of output radiation.

Elnec and Eznec also provide a single command that causes the antenna to
be analyzed at specified increments over a range of frequencies.  The
results of the calculations, as well as the antenna patterns, can be
tabulated and saved to disk.

Eznec can be obtained directly from the author: Roy Lewallen - W7EL, P.O.
Box 6658, Beaverton, OR 97007, for the pricd of $89.00 postpaid in the
USA/Canada; add $3.00 for other destinations.

K6STI's NEC/Wires 2.0 essentially duplicates the analyses offered by
Eznec, although without some of the niceties that Eznec provides.  But,
in turn, his programs offer some advantages over W7EL's.  For one thing,
K6STI has developed a simpler way of specifying antenna dimensions, and
he has made more use of assembler language sub-routines to speed up his
programs.

Mr. Beezley also offers several other antenna programs. An interesting
and unique one is AO 6.5, the Antenna Optimizer.  This program uses the
same type of antenna specification as NEC/Wires and automatically
runs the calculations repeatedly, adjusting the parameters incrementally
to find the optimum values.  The user must specify which variables are
to be optimized: (gain, F/B ratio, or SWR), and the frequency range over
which it will be used.  In addition, the parameters that are to be
adjusted must be selected.  For example, it can optimize the F/B ratio
and SWR bandwidth by varying the lengths of the first director and
driven element in a Yagi.  The program will work for as long as
necessary to identify the exact set of parameters for peak performance.
However, AO is based on Mininec and, once its results are obtained, it
may be wise to check them using NEC/Wires.

A somewhat similar program is YO 6.5 Yagi Optimizer, which optimizes
Yagi antennas, only.  Being dedicated to the one type antenna, it does a
more thorough job of calculating all related variables than would be the
case if AO were used on the same antenna, and also is much faster.

Another program that Mr. Beezley supplies is TA 1.0, a Terrain Analyzer.
It is a ray-tracing program that analyzes the reflection and diffraction
that will affect beams of radio energy from a specific antenna that has
been modeled as with NEC/Wires, in a particular azimuth direction, over
terrain that must be specified using data read from a USGS topographic
map for the specific QTH.  The resulting radiation pattern will be a
more realistic indication of results than an antenna, only, study.

The price of any of K6STI's programs is $60 each, or $40 each for three
or more on one order.  Prices include postage in USA.  Add $5.00 for
international shipping.  They are available from: Brian Beezley - K6STI,
3532 Linda Vista, San Marcos, CA 92069.  Note that, in the past, all of
K6STI's programs were copy protected; but he has now dropped that
requirement.
------------------------------------------------------------------------

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

Title>TC1:More On Selective Calling Systems and Repeaters
Author>Newland, Paul - AD7I
Source>QST Oct 95, pp. 77-78
Abstract>Continues discussion of the utility of DTMF and CTCSS tones
when transmitting through repeaters.  Suggests that most repeaters could
handle DTMF, if the Sysop desired it and/or users knew how to enable it.

Digest>In Technical Correspondence QST Jul 95, Gary Bell - KA1OMA
discussed: "DTMF and CTCSS - How Well Do They Really Work?".  This
letter is a response.  KA1OMA's letter observed that most repeaters do
not repeat either DTMF or CTCSS tones at all, or not with sufficient
fidelity that they can be used at the receiving end.  In this letter,
AD7I suggests that most repeater controllers could pass DTMF tones if
the proprietor wanted it that way, and suggests that users should simply
request that they do so.  In other cases, repeater controllers are
programmed to pass DTMF tones only if a DTMF character "D" is
transmitted ahead the regular DTMF signals.

A different situation prevails regarding CTCSS tones.  These are of such
low frequency that most repeaters attenuate and/or distort them so badly
in retransmission that they are not usable.  Mr. Newland recommends that
mobile transmitters be equipped with a six-dB. per octave rise in
deviation over the audio range of 300- to 3000-Hz.  With such an audio
characteristic, users would find that they could operate through many
repeaters without losing the CTCSS tones.  He admits, however, that
there are other factors affecting some repeaters that would still make
it impossible for CTCSS signals to get through.
------------------------------------------------------------------------

HINTS AND KINKS (HK)
        Conductor: Bob Schetgen - KU7G
                   Asst. Technical Editor
                               _________

Title>HK1:The Revisited WD0O Timer at K6TGA
Author>Tordoff, John - K6TGA
Source>QST Oct 95, p. 75
Abstract>Add a vocal message to the K6TGA timer for ID reminder usage.

Digest>WD0O described an electronic 10-minute timer for identification
reminder in QST Feb 91, and an improvement in QST Jun 94.  K6TGA has now
made a further improvement by adding a "Chip Talker" as described by
K5FOG in QST Dec 91 and QST Sep 92.  Now, when the 10-minute interval
expires, instead of a noisy buzzer, his wife's voice speaks, saying:
"Johnny, it's time to ID".  Hams at the other end of the QSO think that
his wife is sitting beside him, reminding him of the time.

The modifications are described in a circuit diagram with parts list.
                               _________

Title>HK2:Simple Timer Counts Up to 2-1/2 Hours
Author>Premena, S. - AJ0J
Source>QST Oct 95, p. 76
Abstract>Circuit diagram, parts list, and instructions for a simple
electronic timer.

Digest>Described is an electronic timer using a single CMOS IC plus a
half dozen passive components.  It gives an electronic signal at the end
of an adjustable timing period that can range up to as much as 2-1/2
hours.  The CMOS chip draws only about 0.5-milliamps, so the power
supply can be nothing more than a 9-volt transistor battery.

A schematic diagram and full parts list is included.
                               _________

Title>HK3:Reflective Tape for Easier Equipment Retrieval
Author>Kanitra, David R. - WB2AZE
Source>QST Oct 95, p. 76
Abstract>Make identification stickers of reflective tape for use in the
dark.

Digest>Reflective tape, sold by auto parts stores, is excellent for
identifying pieces of equipment that might be used in Field Day, or
other activities that might last into hours of darkness.
                               _________

Title>HK4:Checking the Performance of a Questionable Beam Antenna
Author>Leeson, Dave - W6QHS
Source>QST Oct 95, p. 76
Abstract>How to check a used beam antenna for corrosion problems.

Digest>This letter recommends a way to check the operating condition of
a Yagi beam antenna using traps.  First, with an ohmmeter, check the
continuity across each trap and element joint.  Next, set up the antenna
only a few feet above ground.  Use an SWR bridge or an antenna analyzer
at the feedpoint and note the readings as someone runs their hands over
the elements from the center to the ends.  Erratic changes in indicated
SWR are often good indications of corroded joints, or other problems.
                               _________

Title>HK5:Installing Ground Rods in Heavy Clay
Author>Brown, Hugh - KC5EIY
Source>QST Oct 95, p. 76
Abstract>How to soften clay to ease the driving of ground rods.

Digest>For those locations where hard clay lies only a few inches
(1-inch = 25.4-mm.) below the surface of the ground, KC5EIY suggests
that one sink rods the "easy way".  Use a posthole digger to dig only
through the topsoil to the clay layer, then fill the hole with water and
let it stand for an hour or two.  The next few inches of clay will have
softened and can be removed with relative ease.  Then put 4- to 6-inches
(100-150 mm.) more water in the hole and let the time and water do half
the work.  Repeat as necessary to go down about 5-feet (1.5-m.).  At
that point, drive the last 2-feet (0.6-m.), or so, with a hammer, then
refill the hole with clay about 1-inch (25-mm.) at a time, tamping it
down before adding more.  This procedure increases conductivity between
the rod and true ground.
                               _________

Title>HK6: "Super" Glue Cures Transformer Buzz
Author>Hitt, John - N5JH
Source>QST Oct 95, p. 76
Abstract>Quieting slapping laminations.

Digest>Transformer noise caused by slapping laminations can often be
eliminated by the use of a few drops of cyanoacrylate adhesive ("Super
Glue") dropped on the edge of the laminations.  If the viscosity of the
adhesive is low enough, it will penetrate into the open spaces between
laminations and freeze them into place when it hardens.  Be sure to use
low viscosity glue.
------------------------------------------------------------------------

FEEDBACK (FB)
                               _________

Title>FB1:"Transmission Line Characteristic Impedance and Losses",
        Technical Correspondence, QST Aug 95
Author>Straw, Dean - N6BV
Source>QST Oct 95, p. 78
Abstract>Correction of mistake in a formula and title of table.

Digest>Equation 1 should have been:
        X(0) = (-a/b) * R(0)

The caption for Table 1 should have been: Comparison of
Transmission-Line Characteristics with Different Velocity Factors.
                               _________

Title>FB2:"Bring 'Em Back Alive!", QST Aug 95
Author>Hare, Ed - KA1CV
Source>QST Oct 95, p. 78
Abstract>Suggestions about methods of rehabilitation of old radio gear.

Digest>Mr. Hare, ARRL Lab Supervisor, provides several recommendations
and comments about the subject article which discusses rehabilitation of
antique radio equipment.  Figure 3 in the article showed a mis-wiring of
transformer T1.  Correct wiring is illustrated in a schematic diagram.
The diagram also shows the addition of a 0.5-amp fuse and an On-Off
switch.

The original article showed a meter to measure power supply current; it
was identified as a microammeter.  It should be a milliammeter with a
range of at least 50-milliamps.

The article and Figure 2 showed the addition of a 3-wire power cord, but
some older equipment uses AC/DC circuits that leaves the chassis "hot"
with 120-volt a.c.  Never modify such a circuit!

Also shown is the use of two 0.01-mfd. bypass capacitors in the
transformer primary circuit.  For such service, use only a.c.-rated
capacitors, such as the XY Series, or type GL capacitors.
------------------------------------------------------------------------

NEW HAM COMPANION (NHC)
                               _________

Title>NHC1:The Way We Were: Amateur Radio in the '50s
Author>Thomas, Ronald R. - W8QYR
Source>QST Oct 95, pp. 56-58
Abstract>Ham radio 40-years ago.

Digest>In this article, W8QYR tells what amateur radio was like 40-years
ago.  For many new hams, this was their grandparents' day.  He describes
the Novice license of that day, which was good for only one year and
allowed only CW activity using crystal-controlled transmitters, with
maximum power input of 75-watts, in very narrow segments of certain
bands.  Within the one year, it was necessary to develop a code speed of
at least 13-wpm in order to upgrade to General Class.   Hams who were
not successful lost their licenses.

All equipment used vacuum tubes, and much of it was home built.  During
the decade, amplitude modulation (AM) was gradually losing popularity in
favor of single sideband (SSB).  Amateur stations almost universally
used separate receivers and transmitters; transceivers became available
and popular only in later decades.
                               _________

Title>NHC2:VHF/UHF Mobile in a Late-Model Corvette
Author>Seybold, John S. - KE4PRC
Source>QST Oct 95, pp. 59-60
Abstract>How the author mounted a mobile rig in a Corvette without
drilling holes.

Digest>KE4PRC drives a 1994 Corvette and installed his mobile ham rig
without drilling any holes, at all.  For an antenna, he used a Comet
clip-on window mount, Model WS-1, with suction cups.   He attached it to
the passenger window and ran the coax feedline underneath the armrest
compartment door.  He notes that he must never forgetfully roll the
window all the way down with the antenna clipped on the glass!

The rig that he installed is a Kenwood TM-733A which has a detachable
faceplate.  He mounted the cabinet on the rear deck, with the faceplate
alongside the steering column.  Control wires were routed underneath the
carpet and along the bottom of the door jam.  Power leads make direct
connection with the battery in the engine compartment, then pass through
the accordian boot between the hinges of the door on the driver's side.

Once the installation was completed, the author found that he was
suffering from RFI that emanated from the Central Control Module (CCM),
which is in an ungrounded metal enclosure.  He had the enclosure
grounded by the dealer's shop, then reduced the remaining noise to a
tolerable level by bypassing the power leads to ground using 0.01-mfd.
capacitors.
                               _________

Title>NHC3:The Doctor is IN
Author>Various
Source>QST Oct 95, pp. 61-62
Abstract>Questions and answers of special interest to new hams.

Digest>In this issue, the questions discussed include: difficulties a
newcomer finds in entering conversations on repeaters; which bands are
good for short, medium, and long-range communications; cascading
down-converters to convert 2.4-GHz. first to 2-meters, then to
10-meters; trouble shooting circuits on a PC board; the ACRS
communication system used by airliners; a suitable power generator to
operate a Kenwood TS-450S transceiver in the field; hidden HF antennas;
limitations to the subject material allowed to be discussed in
international conversations in amateur radio; and other subjects.
                               _________

Title>NHC4:Build Your Own 2-Meter Beam!
Author>Botkin, Dale L. - N0XAS
Source>QST Oct 95, pp. 63-64
Abstract>Making a simple and inexpensive 2-meter beam antenna.

Digest> In order to access a distant repeater with his H-T, N0XAS built
a simple and inexpensive 2-element quad antenna that gives substantial
gain in the desired direction.

Using No. 12 copper wire, he formed two squares; 21-3/8 inches
(0.543-m.) on each side, for the reflector, and 20-5/8 inches
(0.524-m.), for the driven element.  The wire ends were positioned in
the middle of one side, soldered together for the reflector, but left
open for the driven element.  The coax feedline was attached by
soldering the shield braid to one of the open ends, and the center
conductor to the other end.

He then made a wooden frame to support the two elements configured with
two sides of each element parallel with the ground and the feedpoint of
the driven element in one of the vertical legs.  The elements are
supported on a boom, initially 9-inches (229-mm.) apart.  The coax lead
runs from the center of the one wire to the end of the boom supporting
that element, along the boom to its center where the mast is attached,
then down the mast to the transmitter.

If an SWR meter is available, the spacing between the elements can be
adjusted to set the SWR ratio to a minimum value.  It should be possible
to reduce it nearly to 1:1.

If the antenna is to be used outdoors, the wooden members should be
protected with preservative or several coats of varnish.  The antenna
boom should be aimed in the desired direction, with the driven element
in front and the reflector behind.
                               _________

Title>NHC5:A Townhouse Dipole
Author>Gress, Mark L. - N0OQC
Source>QST Oct 95, p. 65
Abstract>Suspend a dipole in the attic for a true "Stealth" antenna.

Digest>N0OQC lives in a townhouse where it is undesirable to erect an
outdoor antenna.  He found that the simplest solution to his desire for
an effective HF antenna was to mount a triband dipole in his attic.  He
suspended a Cushcraft Model D3 10-, 15-, and 20-meter dipole from the
rafters using nylon webbing as the support.  The coax feedline was fed
down between the studs, following the house wiring.

He reports excellent results and obtains good signal reports from all
points of the compass.
                               _________

Title>NHC6:Outer Space and *** Space:Following Mir-18 from the
        Dominican Republic
Author>Meara, Bill - N2CQR/HI8
Source>QST Oct 95, pp. 66-67
Abstract>Working the ham station in the Russian space lab Mir.

Digest>Mr. Meara works with the U.S. State Department and is stationed
at the U.S. Embassy in Santo Domingo, Dominican Republic.  From that QTH
he operates N2CQR/HI8.  In March, 1995, he contacted R0MIR, then
operated by Dr. Norman Thagard, an American who was a guest aboard the
Russian Mir Space Station, during several of its passes overhead.  He
describes several QSOs.

After Dr. Thagard had spent some three months aboard the space station,
the American shuttle Atlantis docked with Mir, then brought him home.
------------------------------------------------------------------------

GENERAL INTEREST ARTICLES (GI)
                               _________

Title>GI1:The 1995 Special Olympics World Games
Author>Battles, Brian - WS1O
Source>QST Oct 95, pp. 24-26
Abstract>Amateur activities during the Special Olympics.

Digest>The Special Olympics World Games were organized to allow mentally
retarded athletes from around the world to participate.  The 1995 games
took place in early July in New Haven, CT, centered on Yale University.
Some 7000 athletes from 140 countries competed and about 750,000
spectators attended.  The event was organized and managed by some 50,000
volunteers.

More than 500 amateur radio operators participated, setting up a
special-event station and booths to send free radio messages from anyone
who stopped by.  This article relates a number of anecdotes and
descriptions of amateur radio activities conducted during the games.
                               _________

Title>GI2:20 Years of ARRL DX Contesting From the Foot of the Swiss Alps
Author>Lava, Fabio - HB9AUS
Source>QST Oct 95, pp. 27-29
Abstract>Operating the ARRL DX Contest from the top of a Swiss mountain.

Digest>The ARRL International DX Contest has been held each year for
more than 60 years (excepting the years of WW2).  It consists,
essentially, of everyone else in the world working the USA and Canada.
Mr. Lava first took part in the 1960's as part of a team operating as
HB9QD. They erected antennas on or near the top of a 1700-meter-high
(5500-ft.) mountain and operated for two successive weekends in
sometimes severe winter weather.

For the last 20-years, he and several mates from the earlier HB9QD team
have participated using his call, HB9AUS.  He recounts some of the heavy
snowstorms that sometimes tore down their antennas, and other
adventures.  The biggest change that has affected their contest
operation is the adoption of more and more powerful computers for
logging.
                               _________

Title>GI3:Propagation Pioneers: The ARRL - Bureau of Standards
        Experiment
Author>Welsch, Robert H. - N3RW
Source>QST Oct 95, pp. 46-49
Abstract>Describes a pioneering radio propagation study jointly
conducted by ARRL and the Bureau of Standards in 1920.

Digest>In 1920, six years had passed since the radio spectrum was
divided up and radio amateurs were required to confine their activities
to the relatively "worthless" wavelengths shorter than 200-meters.
Commercial radio had spanned the globe using low to very low
frequencies.  The longest-range stations operated even as low as
20-KHz., where the wavelength is of the order of 10-miles (16-km.)!
Using enormous antennas and extremely high power, they maintained
successful communications over very long distances.

In the meantime, amateurs had found that short waves, at times, provided
long-range propagation with very modest station equipment and antennas.
But the results were erratic, and contacts were subject to fading during
which received signal strengths ranged from very good to inaudible over
periods of seconds or minutes.  Scientists had no clear idea of why
these effects occurred, but they had begun to realize that the short
waves were not as worthless as had earlier been thought.

The US Navy, in particular, had great interest in radio communication
between ships. On April 7 of that year, ARRL President Hiram Percy
Maxim - 1AW met with a group of prominent scientists and they decided
that the US Bureau of Standards and the ARRL would cooperate in a
carefully-controlled test specifically to study the phenomenon of
fading.  The ARRL offered to recruit a number of active amateur stations
to seek their voluntary participation in cooperation with the ARRL
station 1AW, in Hartford, CT and the naval radio station NSF at
Anacostia, Maryland.  Note that no contracts, no federal government
grants, and no lawyers were involved!

In the next few weeks, five amateurs offered their cooperation and their
transmitting stations.  All the stations, except the Navy and
8XK in Pittsburgh, used 60-Hz. rotary spark gap transmitters.  Those two
were equipped with new vacuum-tube continuous-wave (CW) transmitters.
In addition to the transmitting stations, nearly 40 other amateurs
volunteered to listen and keep records of received signal strengths.
All the recorders, except one, were equipped with 3-tube regenerative
receivers.  Geographically they were scattered over most of the northeast
quarter of North America, from Quebec to Tennessee, and from Maine to Iowa.

Test transmissions were made on 250-meters (1.2-MHz.) during evening
hours, for six weeks from June 1 to July 17, 1920.  Each transmission
consisted of the alphabet transmitted 5 times at 18 words per minute.
The recorders listed the approximate signal strength of each letter as
it was heard.

The tests turned out to be among the most important early radio
experiments ever performed.  They clearly proved that fading is not
connected with weather conditions!  The hypothesis that short radio
waves were being reflected and/or refracted by some process not then
understood was strengthened.  Finally, it was clearly shown that
short-range propagation does not show fading effects, whereas longer
range propagation during the same time periods, does.  Thus the
difference between ground waves and sky waves was evident.
                               _________

Title>GI4:Heroes Under Siege
Author>Durakovic, Samir - T94ON
Source>QST Oct 95, pp. 50-52
Abstract>Describing the horrors of Sarajevo under siege, and ham
activities there.

Digest>This article was written by a Bosnian radio amateur in Sarajevo.
He wrote it in the Serbo-Croatian language in early 1995, while Sarajevo
was cut off from the rest of the world except by ham radio.  Several
months passed before he was able to find a way to get his letter taken
through the Serbian siege lines so that it could go to his friend,
Sharon Gartenberg - KC1YR.  She, in time, received it and, with the help
of Janko Gravner, translated it into English.

In it, the writer describes the terrible conditions in Sarajevo, the
capital of Bosnia-Herzegovina, which had a population of 600,000 before
the war began.  More than 10,000 people have been killed in the city,
including 1600 children, and a great many more have been wounded.

Early on, the Serbs severed all telephone connections, and for many
months the only contact with the outside world was via ham radio.
Before long, they learned to seek out and fire at anything that looked
like a radio antenna.  During the siege, a number of the author's ham
friends were among those killed or injured.

The active hams soon became known throughout the city and have been
treated as heroes ever since.  The author remembers, as the saddest
pileup of his life, handling the radio traffic that resulted, in
February, 1994, from the single Serb shell that killed 70 people, and
wounded 200, in a crowded Sarajevo market.  That night, he and a friend
worked on two different 80-meter frequencies throughout the night.

Conditions now are somewhat easier.  Somehow, telephone lines have been
put through to unoccupied areas in the country, and even a few to the
outside world.  Ham radio messages are still being sent, but not with
the urgency and under the pressure of before.
------------------------------------------------------------------------