Xref: news.cs.tut.fi rec.radio.amateur.misc:48393 rec.radio.info:4399 Path: news.cs.tut.fi!news.cc.tut.fi!news.funet.fi!news.tele.fi!sunic!EU.net!howland.reston.ans.net!wupost!gumby!newsxfer.itd.umich.edu!nntp.cs.ubc.ca!alberta!ve6mgs!wvanhorn From: wvanhorn@magnus.acs.ohio-state.edu (William E Van Horne) Newsgroups: rec.radio.amateur.misc,rec.radio.info Followup-To: rec.radio.amateur.misc Subject: Ham Digest - QST March 1993 (Long - 39k) Date: Tue, 15 Mar 1994 04:06:57 -0700 Organization: The Ohio State University Lines: 796 Message-ID: <2m44sh$l2m@charm.magnus.acs.ohio-state.edu> Approved: rec-radio-info@ve6mgs.ampr.ab.ca Lines: 791 HAM DIGEST -- QST, March, 1993 Following are digests of articles printed in the March, 1993 issue of QST. Such digests are being prepared for each issue of QST, and posted periodically. Subsequent issues will be posted one per week until they "catch up" to the current date in mid-1994, thereafter monthly. 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. Worldwide communications are getting better and better. The time has come to make the world's ham press available to all hams throughout the world! 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 own 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. _________ TABLE OF CONTENTS (line number in parentheses - counting from CUT HERE line) TECHNICAL ARTICLES (TA) TA1:The NRY: A Simple, Effective Wire Antenna for 80 Through (68) 10 Meters TA2:Automatic R.F. Power Control for AMTOR Operation (128) TA3:Transmitter Power: What It Is, What It Does, and How to Use It (175) TA4:Predicting Trans-Atlantic 50-MHz. F-Layer Propagation (212) TA5:An Easy, On-Glass Antenna With Multi-Band Capability (272) PRODUCT REVIEWS (PR) PR1:SSB Electronic SP-70 Mast-Mount Preamplifier (325) PR2:Down East Microwave DEM432 No-Tune 432-MHz Transverter (350) PR3:Down East Microwave 432PA 432 MHz. Amplifier Kit (371) HINTS AND KINKS (HK) HK1:Updating the Hy-Gain HDR-300 Rotator (401) HK2:Receiver Muting for Vacuum-Tube Transmitters (423) HK3:When Your SWR Meter Acts Like a Field-Strength Meter (440) HK4:Selective Mike Muting During Data Operation With Some Kenwood (457) Transceivers TECHNICAL CORRESPONDENCE (TC) TC1:Revisiting the 12-Volt Power Supply (479) TC2:More on Elevated Radials (491) FEEDBACK (FB) FB1:Calibrating the Signal Generator in the Sky - QST Nov 1992 (524) NEW HAM COMPANION (NHC) NHC1:Bicycle-Mobile Antennas (548) NHC2:The Paper Chase (560) NHC3:Better Than a Rubber Duck (569) NHC4:The Doctor is IN (586) NHC5:The Day the Repeater "Broke" (597) NHC6:I Passed My Code! Now What? (612) GENERAL INTEREST ARTICLES (GI) GI1:Return to the Arctic and on to the Pole (626) GI2:Packet for Lunch (658) GI3:The Lure of Classic Radio (675) GI4:Crossband-Repeater Operation (705) GI5:K1CE's Secret Oscar-20 Station (733) ------------------------------------------------------------------------ TECHNICAL ARTICLES (TA) Title> TA1:The NRY: A Simple, Effective Wire Antenna for 80 Through 10 Meters Author> Olsen, Rick - N6NR Source> QST Mar 1993, pp. 22-24 Abstract> Describes an HF antenna made of two stacked Extended Double- Zepp antennas fed in phase with open-wire lines. When cut for the 20- meter band, it can be used effectively on all bands from 10 through 80 meters, using an antenna tuner. Digest> Mr. Olsen lives in the State of Washington among a number of fir trees that stand 160 feet tall. Understandably, he makes use of them as antenna supports. He selected a well-known antenna, the Extended Double-Zepp, as the basic building block of an array to erect, and stacked two of them in a "lazy H" fashion, one above the other. He cut them for the 20 meter band and fed them with 300-ohm open-wire line so that he could use tuned feeders and operate them on all bands from 80 through 10 meters. The array that he designed is comprised of two dipoles, one at 100 feet above ground and the other 43 feet, 5 inches below it. Each dipole is 86 feet, 10 inches long, with an insulator in the center. From each side of the center insulator in the top dipole to those of the bottom runs a 43 foot, 5 inch length of lightweight twin-lead in a straight run, not twisted. In the center of that twin-lead, half way between the two dipoles, the main lead to the shack is connected. It is also made of 300-ohm twin-lead. The array is suspended from a catenary rope stretching from one tree to another. Short pieces of twine attach the center insulator and the two end insulators of the top dipole to the catenary. The twine from the rope to the center insulator is approximately 12 inches long and hangs straight down. The pieces of twine supporting the end insulators are somewhat longer and are attached to the rope about ten inches beyond the end insulators. This support tends to put enough tension on the wire to keep it approximately horizontal. >From each end insulator on the top dipole to those of the bottom dipole run 43-foot, 5-inch support ropes. The bottom dipole is held taut by anchor ropes that run from the lower end insulators diagonally downward to the respective tree trunks, thereby keeping tension on both the support ropes to the upper insulators and also the lower dipole itself. The author analyzed the array using Elnec antenna software. On 20 meters, using a height of 100 feet over real ground with coefficients common in the Pacific Northwest, it indicated the antenna's gain to be about 14 dBi. This is more than 11.5 dB. over a half-wave dipole. With his antenna tuner, he uses this antenna on all bands. On 80 and 40 meters, it radiates approximately like a half-wave dipole. On the higher bands, it works better than a dipole. On the 17-meter band, and higher, it develops several major lobes in the manner of long wires, but it performs well on all bands. Mr. Olsen put up two of these antennas, one aimed at Europe and the Middle East, the other at the Caribbean. He reports that they both are very effective. _________ Title> TA2:R.F. Power Control for AMTOR Operation Author> Gregory, Carl D. - K8CG Source> QST Mar 1993, pp. 25-27 Abstract> The AEA PK-232 TNC, when operating in AMTOR mode, provides a signal representing "signal received". This signal is used to cause the input power to be automatically reduced when present, or increased when absent. The result is automatic control of average power at the lowest practical level for prevailing propagation conditions. Digest> Part 97 of FCC regulations, which applies to amateur activities, requires that minimum necessary transmitter power be used at all times. In older operating modes, the transmitting station has no way of knowing how strong the signal is from moment-to-moment at the receiving station, so there is no way to adjust the power output to compensate for fading. In AMTOR "A" (ARQ) mode, twice each second the receiving station sends a signal indicating whether the last three letters were, or were not, successfully received. This nearly continuous feedback signal can be used to increase or decrease the transmitted power. The author operates AMTOR using an AEA PK-232 TNC which provides an electrical signal corresponding to the "signal received" acknowledgement fed back by the receiving station. His transceiver, a Kenwood TS-440, has an ALC (Automatic Level Control) input which can be used to turn the power up or down by varying the d.c. voltage applied to it over a range of about -4.0 to -9.0 volts. He designed and built an interface to take the signal from the TNC, average it through a long time-constant circuit or integrator, and use it to control the power output of the transceiver. His first design was a simple circuit with only seven components. It worked well enough to prove the principle, but was not fully automatic. His final design is still simple, with only 15 components, but is completely automatic. He gives wiring diagrams as well as detailed construction details. Since board layout is not at all critical, he suggests that the circuit be built on "perf-board". Mr. Gregory reports amazement at how little power is required to maintain reliable communications in a great many cases. Since, under automatic control, the power is always edging upward or downward a bit, it tends to keep the error rate, that is the percentage of 3-letter groups that are not successfully received, running around 10 or 15 percent. The same is true under very good band conditions, when the power is turned down to exceedingly low level, or under poor conditions when it is run up to the maximum. _________ Title> TA3:Transmitter Power: What It Is, What It Does, and How to Use It Author> Martin, Diehl - N5AQ and Newkirk, David - WJ1Z Source> QST Mar 1993, pp. 28-31 Abstract> General discussion of output power, received signal level, signal-to-noise ratio, intelligibility, and FCC regulations. Digest> In this article, the authors give a basic discussion of the relationship between transmitter output power and receiver input signal at the other end of the link; and also the relationship between signal received, band-width, and signal-to-noise ratio. They point out that all radio reception includes noise: noise that is generated in the receiver itself; noise that is generated locally from electrical appliances, etc.; noise generated in the atmosphere; and noise that comes from the cosmos. To extract the intelligence that is contained in the received signal, the signal has to be sufficiently stronger than the total of all noise sources. One way to increase signal-to-noise ratio is to increase transmitted power, but that is the poorest way. Using more power than necessary to do the job not only wastes power, it also causes unnecessary interference to others using the channel. It is far more efficient to reduce the noise to the lowest possible level and then transmit the minimum power. Not only is it the most efficient way, it is required by law. As pointed out in the preceeding article, FCC rules require amateurs to use the "minimum transmitter power necessary" at all times. The authors also make good points about maximizing the effectiveness of one's transmitter power. First, a directional antenna can radiate a beam in the desired direction that has several times the effectiveness of the same amount of power transmitted by an omni-directional antenna. Second, use the appropriate band. Every amateur on HF knows the differences in propagation of the different bands over different distances and at different times. _________ Title> TA4:Predicting Trans-Atlantic 50-MHz F-Layer Propagation Author> Pocock, Emil - W3EP Source> QST Mar 1993, pp. 32-34 Abstract> Report of a study correlating geomagnetic A-Index values with transatlantic propagation at 6-meters as compared with theoretical calculations. Hypothesizes that results may show that propagation, when it occurs, is via one hop. Digest> During the winter months of years when the sun-spot cycle is near its peak, the 6-meter band provides frequent openings between New England and Western Europe. Attempts at forecasting when they are likely to occur have not been very effective, even though the methods used work well on the lower bands. The author relates his efforts toward the development of a more effective forecasting procedure. He decided to try to correlate empirical data on past openings, contained in the operating logs of five very active 6-meter operators in the Boston area, with the solar flux and geomagnetic A-Index values which are recorded routinely by the U.S. National Geophysical Data Center in Colorado. The data analyzed were from the periods of November through February in 1988-89, 1989-90, and 1990-91. The five hams were all equipped with multi-element Yagis, favorable locations, and used transmitters with 500- to 1000-watt output power. They are among the ones who are most often listed in European reports of 6-meter DX. Mr. Pocock reduced the accumulated data to a graph with solar flux on the horizontal axis, and percent of days in which propagation was observed on the vertical axis. It indicates that band openings were observed occasionally when the solar flux was as low as 130 and occurred on 50 percent of days when the flux reached about 220 or above. As the flux increased beyond 220, the curve tended to level off, indicating that band openings were observed on between 50 and 70 percent of those days. A surprise was that geomagnetic disturbances did not seem to have much effect except during geomagnetic storms when the A-Index was 30 or higher. Even then, the band was still open about 25 percent of the days. Comparison was made with the predictions that were made by the popular computer programs "Miniprop" and "Ioncap". Both greatly under- estimated the number of openings that were likely. The author knew that those programs assumed that the Atlantic could be spanned only with a minimum of two hops, but he was aware of studies that had demonstrated single-hop paths longer than the 5300 kms. between New England and Western Europe. Accordingly, he used both programs to estimate the openings of a hop of only 3850 kms. centered on the path across the North Atlantic. Programmed for the shorter distance, both programs estimated openings about 50 percent of the days, which matches actual experience. Consequently, the author believes that this shows the openings to be actually single-hop all the way! When the next sunspot cycle again makes conditions favorable, further research may show that forecasting 6-meter openings may be made more reliable by modifying the programs to allow for longer single-hop distances. _________ Title> TA5:An Easy, On-Glass Antenna With Multi-Band Capability Author> Rumbolt, Robin - WA4TEM Source> QST Mar 1993, pp. 35-37 Abstract> Construction article. Building a VHF antenna for windshield- mounting from commonly-available materials. Digest> The author describes an effective VHF antenna which he designed and built around a piece of heat-sink material that he found at a hamfest, a piece of brass welding rod, and some brass stand-offs that are similar to ones available from Radio Shack. It is likely that most hams would find it possible to assemble a unit of similar design whether or not identical materials can be found. The antenna base was made from a piece of extruded aluminum heat-sink material composed of a flat slab with parallel fins rising from it. The clearance between adjacent fins is approximately 1/4 inch and the author cut a small piece of the material, removing all but two adjacent fins to hold the whip antenna. He drilled a single hole through the two fins and inserted a 6-32 screw across the gap, held in place with a lock-washer and nut. The screw, then, was used as a pivot pin. To hold the small diameter whip, he used a common type of stand-off pillar used as hardware in electronic construction. Made of either aluminum or brass, these are fabricated from hexagonal rod, with 1/4-inch dimension from flat-to-flat across the width. Usually they have a longitudinal hole with an internal 6-32 thread, so the author threaded the end of the brass rod to match and screwed it into the hex pillar. Then he drilled a cross-wise hole through the pillar large enough to clear a 6-32 screw. Mounting this on the pivot pin between the fins of the antenna base completes the part of the antenna outside of the car. The antenna base is attached to the outside of the windshield using adhesive foam. On the inside, a steel plate cut to the same dimensions as the antenna base is mounted on the glass. This forms one plate of a capacitor, the other of which is the antenna base; the dielectric is the glass. The installation is completed when the center conductor of a coax cable is connected to the steel plate and the braid to the frame of the automobile. The author gives a table of lengths for cutting the whip to different bands from 45 to 1296 MHz., including 880 MHz. for cellular telephones. He also shows that, by making the base somewhat longer, he can mount two whips on the same base, cut for two different bands, thus accommodating dual-band VHF/UHF transceivers. ----------------------------------------------------------------------- PRODUCT REVIEW (PR) conducted by: James W. Healy, NJ2L Sr. Asst. Technical Editor _________ Title> PR1: SSB Electronic SP-70 Mast-Mount Preamplifier Author> Jansson, Dick - WD4FAB Source> QST Mar 1993, pp. 63-64 Abstract> Performance review of a German-made preamplifier for the 70-cm. band. The reviewer found it effective. Digest> SSB Electronic is a German company that manufactures a broad line of well-made gear. The SP-70 is a low-noise preamplifier for the 430-440 MHz. band. It features automatic switching between receiving and transmitting modes. The amplifier has a noise figure of 0.9 dB. and its gain is adjustable from 10 to 20 dB. The same manufacturer also makes preamplifiers with noise figures as low as 0.3 dB. without built-in switching. The higher noise figure of the SP-70 is a result of the compromise between high performance and convenience. The reviewer's opinion is that the slightly higher noise figure will be an insignificant handicap for all except moon-bounce operations. The unit self-switches from receive to transmit for power levels up to 100 watts output. For signal levels between 100 and 500 watts, it will work well but requires an external sequencer. It is not rated for power outputs over 500 watts. _________ Title> PR2:Down East Microwave DEM432 No-Tune 432-MHz Transverter Author> Healy, Rus - NJ2L Source> QST Mar 1993, pp. 64-66 Abstract> Construction and performance review of a kit for building a transverter to operate on the 70-cm. band with a 10-meter transceiver. Digest> The reviewer offers his opinion that, for an amateur who already has an HF transceiver that covers the 10-meter band, using a transverter is the least expensive way to put a 432-MHz. station on the air. He recommends the reviewed unit as one that "gives top-notch performance at a bargain price." It is supplied as a kit for home construction, or as a completed unit. The reviewer built the kit and relates his experiences in doing so. The output of the transverter when transmitting is limited to 50 milliwatts. As a practical matter, most hams will want to follow it with a power amplifier. The following review evaluates a matching amplifier supplied by the same manufacturer. _________ Title> PR3:Down East Microwave 432PA 432-MHz Amplifier Kit Author> Healy, Rus - NJ2L Source> QST Mar 1993, pp. 66-67 Abstract> Construction and performance review of a 15-watt amplifier designed as a companion with the transverter reviewed in the preceding article. Digest> Mr. Healy followed his construction of the transverter reviewed above by building the matching amplifier kit. It produces 15-watt output when driven by the 50-milliwatts from the transverter. The kit comes with an etched pc board, all required small parts, and some wire for winding r.f. chokes. The builder must supply the case, heat sink, connectors, and feed-through capacitors. The reviewer found that the kit went together easily and that construction required only 30 minutes, not including the prepartations of the case and heat-sink. His summary opinion is that "the 432PA produces enough output for most uses....Never has getting 23 dB. of 70-centimeter gain been so easy and inexpensive." ------------------------------------------------------------------------ HINTS AND KINKS conductor: David Newkirk, WJ1Z Sr. Asst. Technical Editor _________ Title> HK1:Updating the Hy-Gain HDR-300 Rotator Author> Harbach, Allen B. - WA4DRU Source> QST Mar 1993, pp. 68-69 Abstract> Two modifications to improve the performance of a rotator, one to the brake and the other to the direction indicator. Digest> Mr. Harbach made two modifications to his Hy-Gain antenna rotator. First, he added delayed braking. An antenna has considerable rotational inertia and when the motor stops driving, it will continue to turn for a few seconds before coming to a stop. To apply the brake before it stops puts a considerable twisting torque on the mechanism and also the tower. The author's circuit uses a resistor-capacitor time constant to keep the brake held open for some 5- to 8-seconds after the motor voltage is shut off, giving the rotator time to coast to a stop. His second modification was an indicating meter to show the heading of the beam. Circuit diagrams and parts lists for both are included with the letter. All parts are listed by value, and also by catalog number from Radio Shack, and other suppliers. _________ Title> HK2: Receiver Muting for Vacuum-Tube Transmitters Author> Wescott, Tim - KG7LI Source> QST Mar 1993, pp. 69-70 Abstract> Describes an improved method of applying cut-off bias to receiver tubes when transmitting. Digest> Mr. Wescott observes that most vacuum-tube receivers are muted by having a high negative bias applied to the tubes; most of the others by having the cathodes ungrounded. He has developed circuits to apply negative 60-volts to the grids or positive 60-volts to the cathodes to accomplish the same effects. They both include optical isolation that keeps the high voltage confined inside the receiver cabinet. The control is accomplished by low voltage. Two wiring diagrams are included to illustrate both circuits. Only 5 components are used in either circuit. _________ Title> HK3: When Your SWR Meter Acts Like a Field-Strength Meter Author> Samuelson, Robert K. - KA0CLV Source> QST Mar 1993, p. 70 Abstract> The MFJ207 SWR Meter indicator responds to broadcast-band signals giving false high readings. Digest> The author, using an MFJ207 SWR Analyzer with his vertical antenna, was surprised to find that the instrument showed resonance at the proper frequencies, but the indicated SWR did not drop below 3:1. Yet the SWR indicator on his transceiver showed 1.1:1 SWR. Upon investigation, he found that the meter is so sensitive that it was responding to the signal strength of a local broadcast station that was being captured by the vertical antenna. _________ Title> HK4: Selective Mike Muting During Data Operation With Some Kenwood Transceivers Author> Sittner, Dave - N0DET Source> QST Mar 1993, pp. 68-69 Abstract> Describes a simple modification to Kenwood transceivers to allow them to operate normally on SSB while connected to a TNC. Digest> Mr. Sittner reported that on Kenwood TS-940's and TS-440's, if a TNC is connected to operate digital modes via AFSK by plugging the TNC lead into the "Accessory 2" input socket on the rear panel, the rig cannot be used in SSB mode. When the plug was removed from the accessory socket, the rig operated normally. To overcome the problem, he designed and installed a simple circuit that inserts a diode in one of the wires in the TNC connecting cable. A circuit diagram is included. ------------------------------------------------------------------------ TECHNICAL CORRESPONDENCE (TC) conductor: Paul Pagel, N1FB Associate Technical Editor _________ Title> TC1:Revisiting the 12-Volt Power Supply Author> Oscarson, Ed - WA1TWX Source> QST Mar 1993, pp. 71-72 Abstract> Tutorial of design details for power supplies. Digest> Mr. Oscarson gives a review of power supply design methods. He includes the formula for calculating the value of the filter capacitance required to reduce the ripple voltage to a desired level, taken from the ARRL Handbook; also information about the sizes of heat sinks and practical hints about pass transistors. _________ Title> TC2:More on Elevated Radials Author> Christman, Al - KB8I Source> QST Mar 1993, p. 72 Abstract> Report of study showing that with a vertical antenna, 4 elevated radials perform as well as 120 buried in the ground. Digest> This letter contains information of interest to all users of vertical antennas. The writer reports that research on broadcast towers has shown that a few radial wires elevated above ground level perform as well as the "standard" 120 buried radials! He extended the work to ham radio frequencies using the computer program NEC. He discovered that as few as four radials, elevated from the ground, produce results that are as good as with 120 buried in the ground. In his computer model, he used a ground-mounted but insulated tower fed with coax. The shield of the coax was connected to four radial wires near ground level at the base of the antenna; each radial rose at a 45-degree angle to the top of a mast that supported one end of the radial. The other end was also supported by a mast of similar height. He found that the radials can be as little as 4 or 5 feet from the ground (on 80 meters), although a slight addition to signal strength results from raising them to 10 feet or more. The length of the radials should be 1/4-wave plus the radial's height above the ground. For complete information on the research supporting this development, he cites: Christman and Radcliffe, "Using Elevated Radials With Ground- Mounted Towers", IEEE TRANSACTIONS ON BROADCASTING", September, 1991, pp. 77-82. ------------------------------------------------------------------------ FEEDBACK _________ Title> FB1:Calibrating the Signal Generator in the Sky, QST Nov 1992, pp. 42-45 Author> Shuch, Dr. H. Paul - N6TX and Wilson, Paul M. - W4HHK Source> QST Mar 1993, pp. 72 Abstract> Correction of mislabeling of a graph and the caption on a photograph. Digest> In the graph relating solar radiation versus frequency, the horizontal axis was mislabeled. It should have read: Log Frequency (GHz). Since log(1 GHz) = 0, at any frequency below 1 GHz, the log is negative and above that frequency, positive. The caption of Figure 1 states that the diameter of W4HHK's 5.5 meter dish is 17 feet, but 5.5 meters is 18 feet. ------------------------------------------------------------------------ NEW HAM COMPANION (NHC) This is a regular section of QST devoted to articles of primary interest to newcomers to ham radio. _________ Title> NHC1:Bicycle-Mobile Antennas Author> Cerwin, Steve - WA5FRF and Juhre, Eric - K0KJ/5 Source> QST Mar 1993, pp. 52-53 Abstract> Using 2-meter HTs on bicycles. Digest> This article describes the way many hams are using 2-meter FM hand-held rigs to operate mobile on their bicycles. Although most hams seem to use the HTs with only the "rubber duck" antenna, the authors strongly recommend that a resonant 2-meter antenna be mounted on the bike for use when operating the radio. ________ Title> NHC2:The Paper Chase Author> Ford, Steve - WB8IMY Source> QST Mar 1993, pp. 54-55 Abstract> Award certificates. Digest> This article summarizes operating awards and illustrates a representative number of award certificates. _________ Title> NHC3:Better Than a Rubber Duck Author> Kleinman, Joel P. - N1BKE Source>QST Mar 1993, pp. 56-57 Abstract> Superior substitutes for "rubber duck" antennas. Digest> This article does a good job of explaining the "rubber duck" antennas that are standard equipment with most hand-held VHF or UHF rigs (HT's). They are actually helically-wound monopoles designed to resonate on the respective bands but be physically very small. Necessarily, their performance is compromised in order to obtain compactness. Whenever extreme compactness is not required, use of a better antenna will expand the horizons of anyone operating on VHF or UHF. The author describes several options. _________ Title> NHC4:The Doctor is IN Author> Various Source> QST Mar 1993, p. 58 Abstract> Questions and answers. Digest> This feature answers questions frequently asked by new hams. This month, the quesetions discussed had to do with: 2-meter beam antennas, 2-meter packet radio, autopatches, and illegal activities on the ham bands. _________ Title> NHC:The Day the Repeater "Broke" Author> Wolfgang, Larry - WR1B Source> QST Mar 1993, pp. 59-60 Abstract> Description of Continuous Tone-Coded Squelch Systems (CTCSS). Digest> CTCSS is a method of controlling access to the repeater, preventing unauthorized or accidental access. To access a repeater equipped with CTCSS, the transmitting station must transmit a continuous tone of an appropriate frequency assigned to him. There are 42 standard tone frequencies that range from 67 to 254.1 Hz. Most VHF/UHF FM radios have a built-in tone encoader. If a particular unit does not have one, it can probably be added as an accessory. _________ Title> NHC6:I Passed My Code! Now What? Author> Bowles, Chester S. - AA1EX Source> QST Mar 1993, pp. 61-62 Abstract> Basic operating procedures. Digest> This article is directed to new hams who are about to conduct their first QSOs. It explains basic operating procedures, what to expect, and what to say, when. ------------------------------------------------------------------------ GENERAL INTEREST ARTICLES _________ Title> GI1:Return to the Arctic and on to the Pole Author> Gleason, Robert - W3KW Source> QST Mar 1993, pp. 19-21 >Abstract The author was an Arctic explorer in 1929. Recently he returned as a passenger on a Russian icebreaker. Digest> Mr. Gleason was the radio operator on the schooner Nanuk on a voyage into the Siberian arctic in 1929. The ship was caught in the ice and forced to winter near North Cape (now named Cape Schmidt) south of Wrangell Island. Now, after 63 years, he took a summer voyage on a Russian icebreaker that went not only to the same Arctic coast where he spent the winter locked in ice so many years ago, but also north through pack ice to the exact spot of the North Pole! The article relates his adventures in 1929 when, although they were locked in ice, they were far from isolated. Aircraft flew several times out to them from Alaska and landed on the ice near the ship! Today's voyage, however, was a remarkable contrast because the conditions aboard the Russian ship were luxurious. The author was fascinated by the ship which uses two nuclear reactors driving steam turbines to generate 60,000 kilowatts of electricity. Three big propellers, each 18 feet in diameter and driven by its own huge motor, can be reversed from full speed ahead to full speed astern in 90 seconds! The hull of the 20,000 ton ship uses extra thick steel plate and "cruises" at between 7 and 13 knots crashing, banging, and shuddering through heavy Arctic ice. In addition, it is fully equipped for carrying passengers in comfort. During the author's voyage, there were a total of 91 passengers aboard. _________ Title> GI2:Packet for Lunch Author> Larsen, Carol - KA9HFA Source> QST Mar 1993, p. 38 Abstract> Coax cable nearly gnawed through by a rabbit. Digest> This article describes the time that the author's 2-meter packet station almost completely stopped working. Only the closest neighboring station could be heard, and/or contacted. Upon investigation, it was found that the coax cable had been almost completely chewed apart by a rabbit. The problem was solved when the author replaced the cable and covered it with split-loom tubing. _________ Title> GI3:The Lure of Classic Radio Author> Drift, Marty - WB2FOU and Musgrove, Jim - K5BZH Source> QST Mar 1993, pp. 39-42 Abstract> Operating antique equipment. Digest> This an article describing the activities of many hams who are collecting, overhauling, and operating vintage vacuum-tube-based radios. _________ Title> GI4:Crossband-Repeater Operation Author> Witmer, Bob - W3RW Source> QST Mar 1993, pp. 43-46 Abstract> Ways of operating cross-band repeaters. Digest> Most dual-band UHF/VHF transceivers for mobile or home-base provide for cross-band repeater (CBR) operation. In other words, the radio is set up to transmit on one band and receive on the other. The author points out that if one has such a transceiver and also a hand-held UHF or VHF rig, the two can be used together in several handy ways. For one thing, a home-base station will likely be able to access repeaters that cannot be reached using the HT. If the base station is put into CBR mode and set to the same frequencies of the remote repeater, the user will be able to access the repeater using his HT from any location within hand-held range of home base. A second, similar usage might make it possible to access that same remote repeater from inside a partially-shielded office building, or a location where there is a great deal of electrical noise. If a ham parks the car in a parking lot outside their office and leaves the mobile transceiver set on the remote repeater's frequencies, it will be very easy to access the car through the window and thereby contact the repeater. A third option is the case of repeating on transmit only. Many times, it is possible to receive a remote repeater but not access it using an HT. Again, if one's base station or car is within range, then it can be set up to repeat the transmission. In that case, the author recommends that the transmit side of the CBR transceiver be attached to a dummy load so as to avoid unnecessary interference. The author describes several other variations on the theme of using an HT to access a distant repeater through a CBR rig, then discusses certain precautions necessary before commencing CBR operation. First, due attention must be paid to the current drain on the vehicle's battery if the CBR is in a car. Second, care must be taken in selecting the simplex frequency for the communication between the HT and the CBR transceiver, to avoid interference. He recommends that any frequency selected be monitored for a considerable period of time to be sure that it is relatively clear. He advises at least a few weeks' monitoring. Finally, before undertaking such activities, one must be completely familiar with the special FCC regulations that apply to all repeaters. _________ Title> GI5:K1CE's Secret OSCAR-20 Station Author> Ford, Steve - WB8IMY Source> QST Mar 1993, pp. 47-50 Abstract> The Fuji-OSCAR-20 satellite is very easy for hams to use. Digest> This is a tongue-in-cheek article, the sub-title of which is: "Working OSCAR-20 Is Easy, But Don't Tell Anyone!" The pretense is that the author has discovered that Fuji-OSCAR-20 is a very easy satellite to contact and use, but the ham community at large is not aware of it due to the "satellite mystique", the idea that satellite operation is extremely expensive and technically too arcane for the average amateur. He wants to keep it secret so as to have it all to himself. The real point of the article is, of course, to describe what Fuji- OSCAR-20 is and what modest equipment can be used to access it. In fact, it has an exceptionally sensitive receiver and powerful transmitter; the result is that it can be worked with only 20-30 watts output and non-directional antennas. Most of the time it operates as a packet "mailbox" in space. But for several days each month it operates as an SSB/CW repeater! ------------------------------------------------------------------------