DIGEST OF ARTICLES - QST March, 1995 Following are digests of articles printed in the March, 1995 issue of QST. Such digests are being prepared for each issue of QST, and posted periodically. 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 numbers indicated - counting from CUT HERE line) TECHNICAL ARTICLES (TA) TA1:A "Rope Ladder" 2-Meter Quagi 70 TA2:An Audio Break-Out Box 97 TA3:A High-Performance Hybrid Frequency Synthesizer 118 TA4:Try Building Your Own Equipment 174 PRODUCT REVIEW (PR) PR1:ICOM IC-820H VHF/UHF Multimode Transceiver 217 PR2:Azden AZ-61 6-Meter FM Hand-Held Transceiver 263 PR3:Dunestar Model 600 Multiband Bandpass Filter 292 TECHNICAL CORRESPONDENCE (TC) TC1:Receiver Design Comments 328 TC2:Toroid Coupling Feeds Compact Transmitting Loop 354 TC3:Pin Diode Information - Free! 380 TC4:Null Steerer Neatly Nulls Noise 394 LAB NOTES (LN) LN1:Mobile Installations and Electromagnetic Compatibility 411 HINTS & KINKS (HK) HK1:A CW Interface for Commodore C64 and VIC-20 Computers 451 HK2:An Audio Limiter for Use With DSP Filters 473 HK3:Two Hints for the Kenwood TS-850S Transceiver 503 NEW HAM COMPANION (NHC) NHC1:Listen to Learn 545 NHC2:Otherwise Occupied 576 NHC3:Getting Your Club Started in Transmitter Hunting 592 NHC4:The Doctor is IN 628 NHC5:Put Your Pencil Away... 642 NHC6:HF DXing - A Beginner's Primer 683 RADIO TIPS (RT) RT1:The DC-to-Daylight Receiver? 703 RT2:The Automatic Packet Reporting System 729 GENERAL INTEREST ARTICLES (GI) GI1:A Journey to the Center of Asia 757 GI2:Gypsy Hams Go North 785 GI3:The San Bernardino Microwave Society Turns 40 805 ------------------------------------------------------------------------ TECHNICAL ARTICLES (TA) Title>TA1:A "Rope Ladder" 2-Meter Quagi Author>Ford, Jim - N6JF Source>QST Mar 95, pp. 25-27 Abstract>Describes a 35-element 2-meter Quagi beam. Elements are held on 2 parallel ropes, 100-feet long, stretched between posts. Measured gain is 20.6-dBd. Digest>This article is a description of 35-element 2-meter quagi antenna. Its equivalent boom length is 100-feet (30.5-m.), but there is no boom; instead, the quad driven element, the quad reflector, and the 33 rod-type directors are all supported on two ropes stretched between posts. The author constructed the antenna for temporary use, but it could easily be permanently installed. In designing the antenna, he started with the element dimensions shown for an 8-element quagi described in the ARRL Antenna Book. Then he added 27 more directors, cutting them 1/16-inch (1.5-mm.) shorter than the shortest one shown in the book, and spacing them the same as in that antenna. The performance of the long antenna is exceptional; the gain was measured as 20.6-dB! This represents more than 100:1 power gain. It would be an excellent antenna for any point-to-point communication problem, such as accessing a very distant repeater. _________ Title>TA2:An Audio Break-Out Box Author>Spencer, Ben C. - G4YNM Source>QST Mar 95, pp. 28-29 Abstract>Build a box with single, high-impedance input and 5 outputs, four of which have high impedance and one low impedance. Digest>A audio break-out box allows one to feed a single input signal to a number of different loads. For example, a receiver output can be connected simultaneously to a TNC, an external digital signal processor (DSP), and a loudspeaker, with separate gain controls for each output, adjustable from 0- to 20-dB. The unit designed by G4YNM uses a quad op-amp to provide four high-impedance outputs, and an audio power amplifier to provide one low-impedance power output. The entire system is built on a single circuit board and requires a 12-volt d.c. supply. An etched and drilled PC-board is available from FAR Circuits, 18N640 Field Ct., Dundee, IL for $7.50, including domestic shipping. _________ Title>TA3:A High-Performance Hybrid Frequency Synthesizer Author>Rohde, Ulrich L. - KA2WEU Source>QST Mar 95, pp. 30-38 Abstract>Description of PLLs and DDSs used in frequency synthesizers. Suggests a hybrid design of PLL for coarse, and DDS for fine, adjustments. Digest>This is the latest of a series of articles by Dr. Rohde that have been published in QST describing and analyzing various aspects of modern receiver design. The author is a recognized expert in receiver design, in general, and frequency synthesizers, in particular. Among his many publications is a text: DIGITAL PLL FREQUENCY SYNTHESIZERS - THEORY AND DESIGN, published by Prentiss-Hall, Inc., 1983. This article is a guide to design, not a construction article. It will be a valuable guide for a reader who is directly involved in designing receivers and who is quite familiar with state-of-the-art practices in phase-locked loops (PLLs) and direct-digital synthesizers (DDSs). It illustrates what can be accomplished using presently available integrated circuits (ICs), greatly simplifying and economizing high-performance synthesizers for MF, HF and VHF use. However, the author makes no compromises for the benefit of readers whose understanding and familiarity with PLLs and DDSs are hazy, at best. If such readers want to understand thoroughly the lessons that this article teaches, they should review other texts about PLL, DDS, and phase noise. A good place to start is recent editions of the ARRL Handbook. In addition, it would be very helpful to have data sheets describing the various integrated circuits that are used and shown on block diagrams in this article, but not otherwise described. The most important performance characteristics of synthesizers are (1) stability, (2) resolution, (3) settling time, (4) phase noise, and (5) spurious outputs. Stability is obtained from that of the crystal- controlled reference oscillator. The other characteristics are all affected by design decisions involved in the selection of multi-PLLs or DDSs. To some extent there are trade-offs between resolution and settling time. The author points out that by using multi-loop PLLs, designers can obtain very small-step resolution which is indistinguishable from that of a continuously-variable tuned oscillator. But this approach can result in an objectionally long settling time. He makes a persuasive case that a hybrid system using a single PLL for coarse adjustment in steps of tens or hundreds of KHz., combined with a DDS for fine tuning steps, can provide optimum performance. The rest of the article describes, in block-diagram form, a hybrid system that provides excellent performance and uses relatively inexpensive, commonly available components. Included are test results in the form of chart records of phase noise and spectral purity compared with other, much more expensive synthesizers. _________ Title>TA4:Try Building Your Own Equipment Author>Diana, Gary M., Sr. - N2JGU Source>QST Mar 95, pp. 39-42 Abstract>Presents the case for amateurs to build their own equipment. Digest>N2JGU makes a very good case for the pleasure that an amateur can get from building and operating a piece of his own radio equipment. His first construction project was putting together a kit. Next, he decided to build a QRP 40-meter CW transceiver, called "The Ugly Weekender", that had been described in QST Aug 81. He obtained an etched and drilled PC-board that was clearly marked with identification for each component, bought a set of components per the parts list, assembled them onto the board and soldered them. But when he applied power, the unit did not work. At the point, he had learned his first lesson: Assemble a complex board a little at a time, testing each subsection before going on to the next. After considerable frustration, he finally discovered that one of the components, a bypass capacitor, was faulty. When he replaced it with a good one, the system worked. This was his second lesson: Never assume that a component is good, even though it is new. After his second board was finished and operating, he was unable to find an enclosure that he liked so he made his own from pieces of single-sided, undrilled PC-board material. He made a rectangular box keeping the copper face on the inside, assembled the box and soldered the edges of the four sides and the bottom. To provide a removable lid, he attached threaded stand-offs in each of the four corners, held in place with hot-melt glue. Then he cut the top to size and drilled matching holes at the four corners so that the lid can be screwed in place. Since his initial succeses, N2JGU has built a number of pieces of QRP gear using the same construction techniques. A photograph with the article illustrates the attractive final results. ------------------------------------------------------------------------ PRODUCT REVIEW (PR) Conductor: Mark Wilson - AA2Z Editor, QST _________ Title>ICOM IC-820H VHF/UHF Multimode Transceiver Author>Ford, Steve - WB8IMY Source>QST Mar 95, pp. 80-83 Abstract>Review of operation of the IC-820H transceiver, recommended for all uses except satellite operations. Digest>The IC-820H is a dual-band (144/430-MHz.) rig designed for home station use. It operates in FM, CW, SSB and packet modes. Physically, it is very small, less than 10- x 10- x 4-inches (25- x 25- x 10-cm.), weighing 11-pounds (5-kg.), not including power supply. It contains two VFOs for each band and allows either to be selected as the main band, with the other becoming the sub-band; it will both transmit and receive on the main band, but only receive on the sub-band. The reviewer found its performance in terrestial use to be excellent in practically all respects. It really shone in terrestial packet at 9600-bits/s. For satellite operations, the IC-820H has some very good features, and some that are not so good. One feature is useful when one is using the SSB and CW transponders on Oscars 13 and 20. When one is tuning the band looking for contacts, the change of frequency on the main band causes an exactly corresponding change on the sub-band. This is fine at the beginning of a QSO, but soon Doppler shift requires a change to the transmit frequency without changing the receive frequency, or vice versa. The procedure for doing so is so awkward that the reviewer was unable to use it and fell back on two totally independent frequency dials. When he tried operating satellite packet at 1200-bits/s, he found it impossible to follow the Doppler shift without losing data and the throughput suffered greatly. The worst problem occured when he tried to use 9600-bits/s packet. He soon discovered that operating in that mode required that a number of obscure switches be set in a combination that caused the received audio to be cut off. The rig would not operate! A modification to the rig was devised by G3RUH that partially overcomes the problem and makes it possible to operate with the 9600 bits/s Oscars 23 and 25. However, any operator who is seriously interested in satellite operations will probably want to investigate other rigs. The manufacturer's list price for the IC-820H is $1999. The matching power supply is $345 and the hand-held microphone with built-in key pad is $82. _________ Title>PR2:Azden AZ-61 6-Meter FM Hand-Held Transceiver Author>Ford, Steve - WB8IMY Source>QST Mar 95, pp. 83-85 Abstract>Review of an excellent 6-meter hand-held transceiver. Digest>The AZ-61 is a hand-held rig very similar to the same company's 2-meter rig, the AZ-21A. It is small, weighs 1.2-pounds (0.55-kg.) including battery pack, and rugged. Unique for amateur equipment, it carries a 2-year warranty. Six-meter repeaters are becoming more and more popular because of the congestion on 2-meters in many areas. The band has the added advantage that, a few years from now when the next sunspot cycle is in its rising phase, DX contacts will become possible with QRP equipment, such as this HT. The rig's power output can be switched from 0.5- to 5-watts, which makes it capable of accessing rather distant repeaters. It is designed to provide a repeater offset of 500-Hz., which conforms to the most recent ARRL band plan. However, many existing repeaters have not yet changed over from the former standard split of 1.0-MHz. and the AZ-61 cannot be reprogrammed to that split. This limitation, though annoying, can easily be overcome. One only needs to program a memory channel to accommodate any repeater that is still using the old standard. The manufacturer's recommended list price is $379. _________ Title>PR3:Dunestar Model 600 Multiband Bandpass Filter Author>Straw, R. Dean - N6BV Source>QST Mar 95, pp. 85-86 Abstract>Operation review of a bandpass filter for transmit/receive use at a multiple-transmitter site, to avoid mutual interference. Digest>The Dunestar 600 is an in-line filter that works on both transmit and receive. It covers all bands from 160- to 10-meters, but not including the WARC bands. It is bandswitched electrically by remote control. The unit is designed for use at a multi-transmitter site, such as a Field Day, contest, or emergency operation, to prevent interference from and to other nearby transmitters. The filter is rated at 200-watts output, intermittent duty. The reviewer found that that rating is perhaps over-reaching; operating 200-watts with a 40-percent duty cycle for 10-minutes destroyed one or more of its capacitors. A more conservative rating would be more like 100- to 125-watts. The unit was subjected to a number of different tests and its performance was excellent with all of them. It successfully reduced crossband interference to such an extent that there was no noticeable effect on weak signal reception, except when the receiver was tuned to a harmonic of the interfering transmitter. The manufacturer's list price is $229. ------------------------------------------------------------------------ TECHNICAL CORRESPONDENCE (TC) Conductor: Paul Pagel - N1FB Associate Technical Editor _________ Title>TC1:Receiver Design Comments Author>Sabin, William E. - W0IYH Source>QST Mar 95, p. 72 Abstract>Supplementary information to article by Rohde in QST Jun 94. Explains practical constraints on design engineers in commercial manufacturing. Digest>This letter contains supplementary information to the article by Dr. Ulrich Rohde - KA2WEU in QST Jun 94. In that article, Dr. Rohde cited a paper that had been published some years earlier by Mr. Sabin that contained a block diagram of a receiver front end that Sabin had designed. In this letter, Mr. Sabin describes the situation in which the receiver design was made. It was not a design made from scratch; it was a modification to an existing design which had been in production for some time. The purpose of the new design was to make the receiver operate to considerably higher performance specifications under a wide range of ambient temperatures. Furthermore, the allowable addition to the selling price was severely limited. The main point of the letter is to illustrate the practical constraints that design engineers face in commercial production. _________ Title>TC2:Toroid Coupling Feeds Compact Transmitting Loop Author>Hirschberg, Ken - K6HPX Source>QST Mar 95, pp. 72-73 Abstract>An improved method of feeding power to a transmitting loop antenna. Digest>K6HPX describes a compact transmitting loop antenna that he has built using a unique feed method. Most such loops that have been described recently in ham literature feed the main loop by inductive coupling from a physically smaller loop standing along side it. The author feeds his loop using a 1:1 ferrite transformer. His main loop is made of 1-inch (25-mm.) diameter copper pipe. Threaded on the pipe is a ferrite core made of two Amidon FT-240-61 toroids side-by-side. The coax feedline from the transmitter is also threaded through the core. The end of the center conductor is soldered to the shield braid some distance back from the end to form a single turn. Finally, a string of 50 ferrite beads, Number FB-73-2401, are strung on the coax ahead of the loop as a current balun. K6HPX finds that, when he operates his loop on 160-, 80- and 40-meters, he sees an SWR of nearly 1:1 at resonance, without using an antenna tuner. _________ Title>TC3:PIN Diode Information - Free! Author>Katz, Steven D. - WB2WIK/6 Source>QST Mar 95, p. 73 Abstract>Describes a free handbook for circuit designers using PIN diodes. Digest>The Microsemi Corporation, 580 Pleasant Street, Watertown, MA 02172 is offering a free booklet: PIN DIODE DESIGNERS' HANDBOOK, Publication No. PD-600. It is a 40-page booklet including fundamentals of PIN diode design and applications. It will be a valuable aid to any amateur designer using PIN diodes. _________ Title>TC4:Null Steerer Neatly Nulls Noise Author>Olberg, Stirling M. - W1SNN Source>QST Mar 95, p. 73 Abstract>Null steerer is highly successful in suppressing strong radio noise emanating from a nearby high-voltage power line. Digest>W1SNN lives with 140-kV. power lines running through his property. They produce noise on all HF bands continuously, sometimes reaching as high as 10-dB. over S-9 on his receiver. Since he built a null steerer in accordance with W7XC's article in QST Jul 94, he has been able to phase out the noise to the extent that it is almost gone! ------------------------------------------------------------------------ LAB NOTES (LN) _________ Title>LN1:Mobile Installations and Electromagnetic Compatibility Author>Hare, Ed - KA1CV Source>QST Mar 95, pp. 74-75 Abstract>Questions received by the ARRL lab from amateurs installing radios in vehicles, and their answers. Digest>KA1CV, ARRL Laboratory Supervisor, wrote the article: "Automotive Interference Problems: What the Manufacturers Say" in QST Sep 94. In it he reported the results of his survey, including questionnaires and interviews with automobile and truck manufacturers, to determine their attitudes toward customers' installing radio equipment in their vehicles. This article is comprised of questions typical of those that Mr. Hare has received since his article was printed, along with his answers. Most of the questions relate to problems that hams have had in getting information from their dealers, and individual troubles they have encountered in trying to install and operate mobile radios. Some of the common-sense advice the author gives is for the car buyer, before he buys a vehicle, to insist on assurances from the dealer and the manufacturer that what he wants to accomplish can be done and that it will not affect the manufacturer's warranty. As to how the equipment will work once it is installed, his advice is to make a trial installation before buying. If the vehicle is already owned, be sure to follow the manufacturer's guidelines precisely in making an installation. Finally, be conservative. Especially with late-model vehicles that are loaded with electronics used in their operation, do not try to install a high-power amplifier unless the manufacturer has very specific guidelines concerning how that can be done. ------------------------------------------------------------------------ HINTS AND KINKS (HK) Conductor: David Newkirk - WJ1Z Sr. Asst. Technical Editor _________ Title>HK1:A CW Interface for Commodore C64 and VIC-20 Computers Author>Bartlett, F. A. - W6OWP Source>QST Mar 95, p. 70 Abstract>Construction details for a CW interface to use Commodore computers to send and receive Morse code. Digest>The venerable Commodore C64, and its younger cousin, the VIC-20, are still useful in amateur radio applications. W6OWP gives construction information to build a keying interface that will allow one to use the computer and its keyboard to send and receive Morse code. The interface is very simple; it uses a single IC, two transistors, three diodes, and a half-dozen passive components. It can be conveniently built on a small piece of perf-board. In operation, tuning a received CW signal is sharp. When it is properly tuned, an LED flashes in step with the code. The author advises that best copy usually occurs at the lowest audio volume setting that is compatible with fading conditions. _________ Title>HK2:An Audio Limiter for Use With DSP Filters Author>East, Larry V. - W1HUE Source>QST Mar 95, p. 71 Abstract>Construction details of an audio limiter to prevent input signal from saturating a digital signal processor. For effective operation of a digital signal processor, the audio volume must be set so that the received signal strength approaches, but does not reach, the upper limit where saturation occurs. Many digital signal processors (DSP) in use, including the popular W9GR unit, use 8-bit technology and are consequently limited in dynamic range. A common experience in round-table QSOs, in which a number of stations participate, is that signal strengths vary enormously between stations. When the audio gain is adjusted to an optimum for one station, the next station is very apt to be so strong as to saturate the DSP, or so weak that DSP is not effective. To overcome the need for continuously adjusting the gain, W1HUE built a limiter to be inserted between the audio output of the receiver and the input to the DSP. It is a simple circuit requiring only two diodes and a half-dozen resistors and capacitors. With the limiter in use, one tunes in a strong signal and turns up the audio volume until the DSP saturates, then adjusts the threshold control on the limiter until the extreme distortion caused by saturation goes away. From then on, it will be possible to adjust the receiver audio gain without worrying about saturation. _________ Title>HK3:Two Hints for the Kenwood TS-850S Transceiver Author>Shelhamer, Mark - WA3YNO Source>QST Mar 95, p. 71 Abstract>How to remove the broadcast band signal attenuator and also how to prevent excessive operation of transmitter-output-filter relays. Digest>The first of the two hints in WA3YNO's letter has to do with signal attenuators that are automatically switched into use when the radio is receiving on the standard AM broadcast band. Such attenuators are common in modern receivers; their purpose is to avoid intermodulation distortion caused by very strong local broadcast stations. The author provides detailed instructions to allow one to remove the attenuator completely. The editor has inserted a note advising readers who follow this suggestion to use a sharply-peaked, tunable preselector to avoid the IMD that may result. The second suggestion in the letter involves what he considers to be excessive operation of the relays controlling the transmitter-output- filter as he tunes across the radio spectrum during shortwave listening (SWL). He finds the clicking of the relays bothersome. He avoids this by putting the transceiver in split-frequency mode. In that condition, the transmitter band is not switched along with that of the receiver. ------------------------------------------------------------------------ FEEDBACK (FB) _________ Title>"A Function Generator With a Frequency Counter Digital Readout", QST Apr 94 Author>Spencer, Ben - G4YNM Source>QST Mar 95, p. 73 Abstract>In the article, on page 38, Figure 3, the ECG replacement part number for parts DS1 to DS3 should be ECG3075. ------------------------------------------------------------------------ NEW HAM COMPANION (NHC) _________ Title>NHC1:Listen to Learn Author>Keith, Larry - KQ4BY Source>QST Mar 95, pp. 56-57 Abstract>To learn customary practices in amateur radio operating, listen before transmitting. Digest>Operating practices vary greatly between the different modes of amateur radio, and even on different bands. The best way to learn customary operation is to listen and observe before transmitting. As an example, when one first operates on VHF/UHF using a repeater, there are a number of questions to which the answers must be found. The author suggests that, before beginning operations, one should make a notebook containing a number of items of information for each repeater. Essential items include: output frequency, frequency offset, location and callsign, whether or not tone access is required, and the tone frequency; autopatch access codes; time-out timer setting; whether it has a courtesy beep; whether it automatically signals time for ID; whether there are periods when the repeater is reserved for special use; and what types of activities are customary during the various times of day. Operating practices also vary, such as: how stations initiate contacts with each other; how they join a QSO already in progress; how they terminate a contact; and other such customs. Most newcomers want to avoid giving the impression of being neophytes. By listening extensively, one can quickly learn the informal rules of customary procedure that cause one to be recognized as a skilled operator. _________ Title>NHC2:Otherwise Occupied Author>Patterson, Dave - WB8ISZ Source>QST Mar 95, pp. 58, 60 Abstract>Do not let the amateur radio hobby become an obsession. Digest>Usually, the ham radio hobby is beneficial to the participant. It is pleasurable, relaxing, and gives one a respite from the cares of the working world. But in some cases, it can become an obsession. WB8ISZ, in this article, cautions everyone to keep a sense of proportion in our lives. We must never lose sight of the fact that other matters, such as family, home, and the various aspects of daily living are more important than a hobby. _________ Title>NHC3:Getting Your Club Started in Transmitter Hunting Author>Dunn, Si - K5JRN Source>QST Mar 95, pp. 59-60 Abstract>Hints for successful operation of club-sponsored transmitter hunts. Digest>Hidden transmitter hunts, usually referred to as "Fox Hunts", or "Rabbit Hunting", are activities that radio clubs can use for fun and for generating interest in the club among both active and prospective members. K5JRN reports on the Denton (Texas) County Amateur Radio Association hunt activities, and offers some worthwhile suggestions concerning how such hunts should be conducted. The amateur who is acting as the "fox" should not make it easy to find them, but also should not make it too hard. The least desirable outcome would be if all participants should become frustrated, unable to find the target. The prize should not be awarded to the person or group who first finds the "fox". Rather, it should go to the one who runs up the smallest number of miles getting from the starting point to the end of the search. This approach encourages careful deliberation and the most accurate possible direction finding. Most importantly, it does not encourage speeding or careless driving. The Denton club always starts their hunts from the town's central fire station and requires that the fox be located in a public place where the hunters can drive and enter without paying a fee. Ideally, they like to have the chase end in the parking lot of a restaurant where all participants can gather for fellowship and for comparing notes after the hunt is over. _________ Title>NHC4:The Doctor is IN Author>Various Source>QST Mar 95, pp. 61-62 Abstract>Questions and answers primarily of interest to newcomers. Digest>Questions considered in this issue include: computer-generated RFI; r.f. noise from light dimmers; household ground-fault interruptor (GFCI) circuit breakers tripped by nearby radio transmitters; the Farnsworth method of learning Morse code; amateur television (ATV); Universal Time; tapping d.c. power directly from the battery in a mobile installation; and handling CW DX pileups. _________ Title>NHC5:Put Your Pencil Away.. Author>Lee, Craig - AA3HM Source>QST Mar 95, pp. 63-65 Abstract>How modern transceivers and computers can automate many parts of amateur operating and logging. Digest>Most modern full-featured transceivers have computer interfaces available and many, if not most, hams have computers in their shacks. This combination of computers with transceivers makes much of ham radio operating susceptible to automation. The process of preparing an operating log can be almost completely automated. In the special case of operating digital modes, even entering the call sign of a station contacted can be done automatically. In other modes, the call sign must be entered manually but, from that point on, entering the rest of the information can be automatic. The date, time, mode, and frequency are automatically abstracted from the computer's internal clock and through the transceiver interface. If the computer is equipped with a CD ROM drive containing a call sign database, it can be used to provide automatically the name, street address, and QTH of the operator of the station contacted. For contest operating, the same logging program can provide duplicate checking, serial number generation, score calculation, and a calculation of the QSO rate. Station automation is not limited to logging; the computer can control the transceiver. For example, it can act as a memory keyer and automatically send prerecorded messages. In DX operation, it can calculate the beam heading and actually control the rotator to direct it toward the proper heading. It can also track progress toward awards, such as DXCC and WAS. The article finishes with instructions to build a computer-to-radio interface that is required to convert the output of the computer serial port to the TTL (transistor-transistor logic) level required by the radio. It is a simple device that can be built inside the shell of a DB-25 serial port connector. _________ Title>NHC6:HF DXing: A Beginner's Primer Author>Kamman, Alan - NW1S Source>QST Mar 95, pp. 66-69 Abstract>Describes basics of DX operating on HF bands. Digest>NW1S explains the basics of DXing. He describes how the ionosphere makes worldwide DX possible, propagation characteristics of the various HF bands, pileups and working split frequencies, call signs of different countries, the DXCC, and DX contests. He ends by referring readers to more complete information in THE ARRL OPERATING MANUAL, and YOUR DXCC COMPANION, by Jim Kearman, KR1S. ------------------------------------------------------------------------ RADIO TIPS (RT) These are short items, scattered among the articles in the New Ham Companion section, of interest to newcomers. _________ Title>RT1:The DC-to-Daylight Receiver Author>Phillips, Curt - KD4YU Source>QST Mar 95, p. 65 Abstract>Modern receivers that provide extremely wide operating bandwidth. Digest>The bandwidth of an idealized ultimate radio receiver might be defined as "DC-to-Daylight". Although these limits will never be achieved, there are now available scanners that cover from 100-KHz. to well past 1-GHz. One of the first of these was the AOR AR-1000, which was a tiny package only 6.7- x 2.6- x 1.4-inches (170- x 66- x 35-mm.) in size. Later, ICOM introduced their R-1, which is even smaller. It covers 100-KHz. to 1300-MHz. in steps as small as 500-Hz. Then the Japanese company, Yupiteru (Japanese-English for "Jupiter") introduced their Model MVT-7100, that covers 100-KHz. to 1650-MHz. in steps of 50-Hz! Finally, AOR brought out their Model AR-8000, which covers 100-KHz. to 1.9-GHz. in 50-Hz. steps. It also provides a 4-line alphanumeric display and a computer interface. Now, in accordance with a law effective in mid-1994, no scanning radio can be manufactured in, or imported into, the USA that covers the cellular phone frequencies between 800- and 900-MHz. A model of the AR-8000 is now available with those frequencies deleted. _________ Title>RT2:The Automatic Packet Reporting System Author>Horzepa, Stan - WA1LOU Source>QST Mar 95, p. 69 Abstract>The APRS allows tracking movements of mobile stations on a map. Digest>The Automatic Packet Reporting System (APRS) allows packet radio to track real-time events. It was developed by Bob Bruninga - WB4APR. APRS provides a graphic display of the location of stations and their movements on a map. Any packet station can add their latitude and longitude to their beacon transmissions; any station monitoring them, that is equipped with APRS software, will display the map with the station positions superimposed on it. Any mobile station that is equipped with a GPS receiver can transmit its position continuously as it is moving. This will allow others to track that movement remotely. The APRS is also an excellent tool to display triangulating bearings from several locations to spot a hidden transmitter. APRS software for IBM PC compatible computers is available from WB4APR, 115 Old Farm Court, Glen Burnie, MD 21060. A MacIntosh version is also available. ------------------------------------------------------------------------ GENERAL INTEREST ARTICLES (GI) _________ Title>GI1:A Journey to the Center of Asia Author>Langdon, Terry - W6/G3MHV Source>QST Mar 95, pp. 43-45 Abstract>Story of a ham's visit to the Russian Republic of Tuva in the center of Asia. Digest>Along the southern border of Russian Siberia, adjoining the north-western border of Mongolia, is the Russian Republic of Tuva, a part of the Russian Federation. The author had occasion to make a business trip through all of Russia, from Moscow to Vladivostok. While on it, he took a detour to visit this land. It is a large country, by European standards, four times the size of Switzerland, but has a population of only about 300,000 people. It is located at the exact center of the Asian continent. Tuva, with Mongolia, western China and Tibet, comprise CQ DX Zone 23. When he arrived at Kyzyl, the capital of the republic, he received a friendly and enthusiastic reception from several hams. With their help, he quickly was able to obtain licenses that allowed him to operate R0/KA6ZYF and R0/G33MHV. In addition, his new friends lent him the use of a transmitter and amplifier. With that rig, and a ground-plane antenna, he operated SSB on 20-meters and caused massive pile-ups from Japan to Europe. Propagation conditions at the time made contacts with the USA impossible. _________ Title>GI2:Gypsy Hams Go North Author>Stoner, Jeannie - WH6DZ Source>QST Mar 95, pp. 43-45 Abstract>Travelog of hams through Alaskan and Canadian arctic. Digest>This is a travelog describing the trip that the author and her husband made through the Canadian and Alaskan arctic in 1993. They drove through British Columbia and picked up the Alcan Highway in Dawson Creek. After traveling that highway, from one end to the other, they reached Tok, Alaska. From there they drove the Top of the World Highway into the Yukon Territory and up the Dempster Highway to Inuvik, Northwest Territory, crossing the Arctic Circle enroute. Inuvik is the northernmost place it is possible to reach on an established road. Their mobile home is equipped with HF and VHF rigs, a computer, TNC, a mobile antenna, and portable antennas that can be strung in trees. They used ham radio to make friends everywhere along the entire trip. _________ Title>GI3:The San Bernadino Microwave Society Turns 40 Author>Laag, David E. - WA6OWD Source>QST Mar 95, pp. 46-50 Abstract>History of the SBMS. Digest>The San Bernadino Microwave Society (SBMS) was formed by a small group of amateurs in San Bernadino County, California, in March, 1955. The primary founders were "Tommy" Thompson - W6IFE and Bill Baird - W6VIX. Individual experimenters had been active for ten years, since the end of WW2, and several of the members were active on the 9-cm. band. In 1957, the SBMS published its first Microwave Handbook, and a year later Dale Bredon - W6BGK wrote a QST article providing details of the San Bernadino 9-cm. gear. In the 1960's and '70's, activities grew; in the '80's microwave became accessible to all amateurs. In 1986, the first ARRL 10-GHz. Cumulative Contest was run and the four highest scores were run up by SBMS members. Now in 1995, the society is more active than ever, and remains committed to "an expanding role in helping guide the amateur microwave community". ------------------------------------------------------------------------ wvanho@infinet.com