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Newsgroups: rec.radio.amateur.misc, rec.radio.info Followup-To: rec.radio.amateur.misc Approved: rec-radio-info@ve6mgs.ampr.ab.ca DIGEST OF ARTICLES -- QST, June, 1993 Following are digests of articles printed in the June, 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>A Comparison of Solid-State and Tube-Based Receiver Systems (80) Using CAD TA2>Home-Brewing a 10 GHz. SSB/CW Transverter - Part 2 (133) TA3>A Small Loop Antenna for 160 Meters (157) TA4>An Introduction to Amateur Television - Part 3 (222) PRODUCT REVIEW (PR) PR1>QST Compares: Dual-Band Mobile FM Transceivers (265) HINTS AND KINKS (HK) HK1>Grid-Current-Trip Circuit With a Ten-Tec Linear Amplifier (355) HK2>No Guess-Work Method for Finding the Correct Length for (375) 1/4-Wavelength Stubs HK3>Corona, Anyone? (413) HK4>A Ground-Radial Installation Tool (429) HK5>Tracking a Defective Transformer (443) HK6>A Dummy-Load/Power Indicator (451) TECHNICAL CORRESPONDENCE (TC) TC1>Getting to the Core of the Problem (473) TC2>Conductivity in the Cold, Cold Ground (490) LAB NOTES (LN) LN1>Curing Interference to Non-Radio Equipment (515) FEEDBACK (FB) FB1>Build It Yourself from QST - Part 3; QST Jun 92, pp. 42-45 (533) FB2>A High-Dynamic-Range Receiver Front End, QST Feb 93, pp. 23-28 (538) NEW HAM COMPANION (NHC) NHC1>Get Ready for Field Day! (559) NHC2>Tall Stacks '92 Special-Event Station (570) NHC3>Pack-in-the-Box (593) NHC4>Your Information Connection: The ARRL BBS (615) NHC5>The Doctor is IN (637) RADIO TIPS (RT) RT1>What's Your RST? (653) GENERAL INTEREST ARTICLES (GI) GI1>Roving for VHF Gold in the Colorado Rockies (694) GI2>The Rise of Frequency Modulation (718) GI3>The Radio is My Passport (739) GI4>Phase 3D: A Satellite for All (755) ------------------------------------------------------------------------ TECHNICAL ARTICLES (TA) Title>TA1:A Comparison of Solid-State and Tube-Based Receiver Systems Using CAD Author>Rohde, Ulrich L. - KA2WEU/DJ2LR/HB9AWE Source>QST Jun 1993, pp. 24-28 Abstract>A study of how much improvement in performance has resulted from modern developments in solid-state components and design. Tests were made of 1960's era vacuum-tube receivers compared with modern ones. For frequencies under 150 MHz. it was found that the best receivers from the 1960's performed practically as well as modern ones, but higher frequencies require modern GaAs components for top performance. A contribution to the improvement even more important than new hardware has been modern techniques for designing low-noise mixers. Digest>The author reports the results of a study he made regarding whether, and by how much, modern solid-state VHF and UHF receivers have been improved over the vacuum-tube models of a generation ago. Specifically, although noise-figure and sensitivity have been greatly improved, some still argue that the dynamic range divided by the noise floor has not really been that much improved. To answer the questions, he obtained some equipment that represented the state-of-the-art design of the 1960's, made thorough laboratory measurements, and compared them with similar measurements made on current equipment. Then he modeled the circuits of both types on a computer and calculated performance data using a modern software program which is one of the best available in the field of computer-aided design (CAD). Since the results of the computer calculations matched the test results very closely, he was confident that he could expand the study over a wider range of variations using the computer than would be possible in the laboratory. His article represents a highly technical, though non-mathematical, version of the complete report which was published in QEX, April, 1993. He shows print-outs of many graphs representing a very thorough analysis of operating performance of various circuits over the range of 100-200 MHz. If the technical background of the average ham can be defined as that of the ARRL Handbook, it is probable that many will not understand all the technical discussion of this article. However, they will have no difficulty understanding the author's findings. He discovered that with the best vacuum tubes of the day, it was possible to get good low-noise amplifier performance up to about 150 MHz.; but to extend that performance into the microwave region requires modern gallium-arsenide FETs. In his investigation, he came to realize that the biggest failing of vacuum-tube receivers 30 years ago was in the design techniques of mixers, rather than in the hardware. He states that it was possible at that time to build a receiver with a third-order input intercept of 30-dBm., but very few achieved that level. _________ Title>TA2:Home-Brewing a 10 GHz. SSB/CW Transverter - Part 2 Author>Lau, Zack - KH6CP Source>QST Jun 1993, pp. 29-31 Abstract>Descriptions of the pre-amplifier, mixer, and power amplifier complete the two-part article. Also discusses antennas. Digest>This article completes the description of the 10 GHz. Trans- verter begun in last month's issue. In this part, The author covers the pre-amplifier, mixer, and power amplifier, completing the system. He finishes with some recommendations regarding antennas. The receive- and transmit-amplifiers are identical in construction. The only difference is that the bias current is adjusted to be three times higher in the transmitter. The wiring diagram shows relatively few parts and most of those are strip-lines etched onto the board. For antennas, Mr. Lau recommends building a low-gain horn and mounting it in front of a parabolic dish. The parabola need not be precise, everything from trash-can lids to snow-sleds have been used successfully. The author reports that he has made contacts over distances in excess of 120 miles with his unit. _________ Title>TA3:A Small Loop Antenna for 160 Meters Author>Mozzochi, Charles J., pp. 32-34 Source>QST Jun 1993, pp. 32-34 Abstract>Describes a single-turn "magnetic" loop antenna for 160 meters 80-feet (24 meters) in circumference, made of 1-inch (2.5 cm.) diameter copper pipe. Quarter-wave radials are buried under the loop, but not connected to it. Mentions, but does not describe, the motorized main tuning capacitor. Digest>This article describes a loop antenna designed for use on the 160-meter band. The radiator is made of 8 pieces of 1-inch (25 mm.) copper pipe, each 10-feet (3 m.) long, connected together by 45-degree elbows. This forms an octagon approximately 24-feet (7.3 m.) in diameter, and it is mounted vertically, suspended from a rope between two trees. The bottom side is horizontal, one-foot from the ground, and is cut in the middle so that a tuning capacitor can be inserted. The author used a 200 pf. variable vacuum-capacitor, but suggests that a split-stator capacitor could be used instead. Other references have cautioned that in such a case, every piece of the capacitor must be soldered or welded together. Small loop antennas have such exceedingly low radiation-resistance that every effort must be made to reduce the ohmic resistance of the metal components to the minimum possible. Conventional capacitor construction with simple compression joints would cause such high loss that it would destroy the effectiveness of the antenna. To feed the antenna, a small loop is mounted in one of the lower corners, in a parallel plane approximately 10-inches (25 cm.) away from that of the octagon. The feed line is connected to it and power gets transferred to the large loop by inductive coupling. The smaller loop is made of 5/8-inch (16 mm.) soft copper tubing, 15-1/2 feet (4.7 m.) in circumference. It is bent into a circle approximately 5-feet (1.5 m) in diameter. Like the main loop, the small loop is opened at the bottom; a fixed capacitor of 1000 pf. is soldered between the ends. The author makes up the 1000 pf. by connecting ten 100-pf. "doorknob" capacitors in parallel, tied together with copper strap. The coax feedline is soldered to the small loop on each side of the capacitor; the shield soldered to it directly and the center conductor through a 740 pf. doorknob capacitor. Underneath the antenna, Mr. Mozzochi installs 12 quarter-wavelength radials, connected together at the center. They are not attached to the loop electrically, but they appreciably reduce ground loss. If full-size quarter-wavelength radials cannot be accommodated, ground wires as short as twice the loop's height (50-feet, or 15 m., long) can be used and should be oriented parallel to the plane of the loop. To adjust the antenna, the author suggests that the small loop be mounted near one of one of the lower corners of the outer loop, and parallel to it, but about 20-inches (50 cm.) from the plane. The main tuning capacitor should be adjusted to get minimum SWR, then the smaller loop physically moved to reduce the SWR to near 1:1. Each movement of the loop's position may require retuning the main loop to resonance. Once a low SWR position is found, it should allow operation over the entire 1.8-2.0 MHz. band at very low SWR. The author points out that a change of frequency of more than 2- or 3-KHz. requires retuning of the main capacitor, hence recommends motor-drive with remote control from the shack, but does not indicate what type of drive he uses. _________ Title>TA4:An Introduction to Amateur Television - Part 3 Author>Taggart, Ralph E. - WB8DQT Source>QST Jun 1993, pp. 35-41 Abstract>Completion of the 3-part series. Discusses practical operating practices and activities. Discusses range and power output required. Digest>This is the third, and final, part of this article. Mr. Taggart opens with a discussion of group activities and suggests that local hams interested in ATV should set up an informal schedule to meet at a regular time on the air. If most ATV work is on the 70-cm. band, the 2-meter band can be used for coordination of activities. When first establishing contact with another station, one should start out transmitting large, high-contrast block images, such as a black-on-white call sign. Once good reception is achieved with high-contrast images, more complex and subtle colored images can be explored. For reaching longer distances, power amplifiers should be considered. Commonly called "brick" amplifiers, a wide range of choices are available. The best choice may be a final amplifier mounted at the antenna, saving the losses that would otherwise be incurred in the transmission line from the shack. Use of any power amplifier brings with it some complications, which the author discusses. In areas where there is a reasonable concentration of ATV-active amateurs, repeaters are in use which expand the range for all participants, just as in the case of conventional radio repeaters. If a single-band repeater is established, as opposed to cross-band operation, it will make use of Vestigial Sideband (VSB) mandatory. VSB modulation has other desirable characteristics, as well, although this is subject to some controversy. The author finishes the article by suggesting that anyone who is interested in learning more about ATV consider subscribing to AMATEUR TELEVISION QUARTERLY. The publisher can be reached at 1545 Lee Street, Des Plaines, IL 60018-1950. ------------------------------------------------------------------------ PRODUCT REVIEW pp. 66-71 conductor: James W. Healy, NJ2L Sr. Asst. Technical Editor _________ Title>PR1:QST Compares: Dual-Band Mobile FM Transceivers Author>Healy, James W. - NJ2L Source>QST Nov 1993, pp. 66-71 Abstract>A review of specifications and operation of six dual-band VHF/UHF FM Transceivers: Alinco DR-600T, Icom IC-2410H, Kenwood TM-732A, Standard C5608DA, and Yaesu FT-5100. Digest>This is a summary review of six different dual-band transceivers from five different manufacturers: Alinco, Icom, Kenwood, Standard, and Yaesu. Six ARRL Headquarters staff members performed the reviews. All six of the rigs provide some features in common, including remote control and frequency entry from the microphone, cross-band repeating, small-size for dashboard mounting, operation from 13.8 volts plus/minus 15 percent, and other obvious features. The units reviewed are as follows: Alinco DR-600T. The reviewers found this unit to be solidly built and attractive. Both transmitter and receiver audio are of good quality; the loudspeaker delivers sufficient sound for most normal operation at highway speeds. Two minor annoyances are: first, the dual concentric knobs that control volume and squelch settings are too close together for easy operation. Second, the amount of force to hold the push-to-talk button closed is a bit too much for comfortable long operating. Icom IC-2410H. This is one of the smallest of the radios reviewed. It provides DTMF remote control and simultaneous dual-frequency receive. Both transmitted and received audio are clear. Programming it is complex. Icom offers, as an optional extra, a voice synthesizer which speaks the display data so that mobile operators need not take their eyes off of the road for tuning. Icom IC-3230H. This unit is very similar to the IC-2410H except that it does not provide the dual frequency reception that the other does. The reviewers found the 3230H somewhat easier to program. Kenwood TM-732A. This unit is also very small, approximately the same size as the two Icom radios. It provides dual-frequency receive capability, and also has a timer that can be set to cut off the transmitter after a given period length of time. Its transmitting and receiveing capabilities are good. The reviewers were critical over the difficulty of programming the radio and also the fact that it uses a unique microphone connector similar to current American telephone plugs. The reviewers question the durability and lack of easy availability of replacement plugs. They found the unit overall to be attractive and solidly built, and fairly easy to use. Standard C5608DA. This unit provides one function which none of the others offers: a full-function remote-control microphone including frequency display, power switch, and audio-gain control. The rig is larger in size than the others which, in turn, makes the front panel larger so that the knobs and buttons are more convenient. Receiver coverage is the widest of any of the reviewed radios, giving access to the aircraft band starting at 118 MHz. and also a good bit of the UHF spectrum starting at 320 MHz. Its performance is good in both transmitting and receiving. Yaesu FT-5100. This unit received good remarks from the reviewers on a number of items, including the transmitted audio quality, easy operation, "vast number" of memory channels, and automatic display dimming. It is the only one of the six that, when scanning, always stops on the center frequency of a signal. All others tend to stop to one side of the center of frequency. Another feature is dedicated jacks for interfacing a packet TNC. Some reviewers criticized the front-panel ergonomics, finding the controls a bit harder operate than on some of the others. The reviewers' summary indicated that all six units delivered good basic performance. The one that was found to have the most good features and versatility was the Yaesu FT-5100. The larger Standard C-5608DA was thought to be a better choice for a home-station, FM only, radio. Because of their small size and resulting necessity of using small speakers, it was felt that all units would benefit from the use of external, larger, loudspeakers. They also noted that only the Yaesu FT-5100 manual included instructions for connecting a TNC to provide packet operation. The others were criticized for that omission. The review ended with advice to prospective buyers: decide the features that are most needed; read the manuals for each radio under consideration; inspect each of them closely at a dealer's display before buying. ------------------------------------------------------------------------ HINTS AND KINKS conductor: David Newkirk, W1JZ Sr. Asst. Technical Editor _________ Title>HK1:Grid-Current-Trip Circuit With a Ten-Tec Titan Linear Amplifier Author>Gow, Harry - G3LAG/I2HGY Source>QST Jun 1993, p. 74 Abstract>Describes a modification to the Ten-Tec Titan amplifier so that excessive grid current will automatically cause shut-down, protecting the tube from damage. Digest>The Ten-Tec Titan linear comes equipped with a bright red LED that lights up when too much grid-current flows, but does not automatically take corrective action. The author was not comfortable with the lack of protection and designed a simple circuit that opens a relay, putting the amplifier in stand-by, any time the LED comes on. This, then, requires the operator to reset the relay manually to get the amplifier back on the air. A wiring diagram is included. _________ Title>HK2:No Guess-Work Method for Finding the Correct Length for 1/4-Wavelength Stubs Author>Healy, Rus - NJ2L Source>QST Jun 1993, pp. 74-75 Abstract> Digest>This item shows a diagram and explains a method of using the station transmitter to provide a direct measurement that allows a quarter-wave coaxial stub to be cut to a precise dimension on any band on which the rig can transmit. The output of the transmitter is connected through an SWR meter to a coaxial "Tee" connector. On one side of the Tee, a 50-ohm dummy load is connected. The other side goes to the coaxial stub under test. At the beginning of the test, the stub is deliberately cut too long and a short is placed across the far end. The transmitter is set to emit a small amount of power, just enough to actuate the SWR meter, and the SWR is measured. Presumably, it will be something greater than 1:1, unless by accident the stub is already cut to 1/4 wavelength. If it is not, a bit is pared off the end, it is re-shorted, and re-measured. This procedure is repeated until the indicated SWR is reduced to 1:1. At that point, the input impedance of the stub is nearly infinite and the transmitter "sees" only the dummy load. The Hints and Kinks editor has appended a comment pointing out that the described technique works only on cables of the same impedance as the system they are used with, i.e. 50-ohms. But it can also be used with feedlines of any other impedance with appropriate transformation. He also points out that the same technique can be used in cutting cables of any electrical length by determining the frequency at which the desired length is 90-degrees. As an example, a 49-degree length at 7.0 MHz. is 90-degrees at 12.85 MHz. If the transmitter can be made to emit power at that frequency, the stub can be adjusted as described above. This is not illegal operation so long as the dummy load does not radiate appreciable power. _________ Title>HK3:Corona, Anyone? Author>Thurston, George L., III - W4MLE Source>QST Jun 1993, p. 75 Abstract>How the variable inductor of an antenna tuner should be connected. Digest>Mr. Thurston points out that, often, antenna tuners are built with a tapped- or roller-inductor. In some of them, one end of the coil is left open-circuited. When it is operating with the contact far down on the coil, very high voltages can develop at the open end and corona discharge can result. The solution is not to leave the end of the coil open-circuited; use the tap-switch or roller to short out the unused portion of the coil. _________ Title>HK4:A Ground-Radial Installation Tool Author>Hoyt, Emerson M. - WX7E Source>QST Jun 1993, p. 75 Abstract>Describes a convenient way to bury radial wires in the ground. Digest>When installing radial wires underneath the turf, the author cuts a slit through the sod with an edger or spade, opening a vee-shaped trench by rocking the blade back and forth. He lays the wire in the trench and pushes it down with a tool having an inverted vee notch in the end. The tool that he finds useful is a Stanley No. 10T nail remover. _________ Title>HK5:Tracking a Defective Doorbell Transformer Author>Schneider, Roger - WB9OJR Source>QST Jun 1993 Abstract>Describes a case of RFI which was found to be caused by a doorbell transformer in the complainant's house. _________ Title>HK6:A Dummy-Load/Power Indicator Author>Klaus, George H. and Forster, Robert M. - W2DVG Source>QST Jun 1993 Abstract>Describes a dummy load with a power meter attached for QRP transmitter measurements. Digest>The authors show a diagram of a low-power dummy load and power meter they fabricated from 12 one-watt resistors of 620-ohms each, wired in parallel. To measure power dissipated, they measure the voltage that is developed across the parallel resistances using a circuit that includes a 0-1 milliamp d.c. meter with a .01 mfd. by-pass capacitor across it. The meter is wired in a circuit in series with a rectifying diode and a 12,000-ohm, 1/2-watt resistor. The series circuit is attached across the resistor bank and, in effect, measures the voltage developed across the load when the transmitter is operating. ------------------------------------------------------------------------ TECHNICAL CORRESPONDENCE conductor: Paul Pagel, N1FB Associate Technical Editor _________ Title>TC1:Getting to the Core of the Problem Author>Czuhajewski, Michael A. - WA8MCQ Source>QST Jun 1993 Abstract>Wire size has very little effect on the inductance of toroidal inductors. Digest>The writer takes issue with statements in an article written by Zack Lau, KH6CP/1 in April, 1992 QST. Mr. Lau, describing the winding of toroidal inductors, suggested that changing from No. 22 to No. 28 wire would cause a significant increase in inductance of a particular coil. Mr. Czuhajewski suggested that the difference Mr. Lau found was likely caused by a difference in the toroidal cores, and that the change in wire size is inconsequential so long as the dimensions and number of turns remain the same. _________ Title>TC2:Conductivity in the Cold, Cold Ground Author>Lewallen, Roy - W7EL Source>QST Jun 1993, p. 73 Abstract>Freezing weather conditions usually has little effect on ground conductivity. Digest>Mr. Lewallen replied to a question received from a reader about what happens to the performance of a grounded vertical antenna when the ground freezes. He reported that, whereas the conductivity of water drops on the order of 100 times when it freezes, that of soil changes much less. If the grounded antenna uses radials, the conductivity of the wire is electrically in parallel with that of the ground, so the change in overall conductivity is correspondingly much less. Finally, unless the ground freezes to a depth of several feet, even a large change of conductivity in the frozen layer would not make that much difference. In most areas of the USA, the soil never freezes to that depth. ------------------------------------------------------------------------ LAB NOTES conductor: Steve Ford, WB8IMY Asst. Technical Editor _________ Title>LN1:Curing Interference to Non-Radio Equipment Author>Hare, Ed - KA1CV Source>QST Jun 1993, pp. 64-65 Abstract>A tutorial on fixing problems of interference to consumer-electronics apparatus other than radios. Digest:Questions and answers concerning fixing problems of RFI with telephones and many other types of consumer electronic equipment. A number of points stressed are: diplomacy; FCC regulations that require manufacturers of consumer electronics to make them immune to lawful radio transmissions; the ARRL EMI/RFI Package and other help available; and the correct use of chokes and filters to cure stubborn cases. ------------------------------------------------------------------------ FEEDBACK (FB) Title>FB1:Build It Yourself from QST - Part 3, QST Jun 92, pp. 42-45 Author>Hale, B. Source>QST Jun 1993, p. 73 Abstract>In Fig. 11 on p. 42, labels for emitter (E) and collector (C) of Q1 are transposed. C should be left and E right. _________ Title>FB2:A High-Dynamic-Range MF/HF Receiver Front End, QST Feb 93, pp.23-28 Author>Makhinson, J. Source>QST Jun 93, p. 73 Abstract>The article contains the following errors: In fig. 9: The circled numbers 1,2,3,4,5 are in incorrect order. They should be 1,2,5,4,3. The designer of the Si8901 was not Robert Zavrel, but Ed Oxner. The spectrum display on the first page is confusing. Read p. 3 of the information package referenced in the article's Endnote 2. Transformers T3,T4,T7, and T8 need not be Model T1-1T. They can be Model T1-1 (without the "T"). ------------------------------------------------------------------------ NEW HAM COMPANION This is a regular monthly section of QST that contains articles of primary interest to newcomers to the hobby. _________ Title>NHC1:Get Ready for Field Day! Author>Ford, Steve - WB8IMY Source>QST Jun 1993, pp. 54-56 Abstract>A description of Amateur Radio Field Day: what it is, the range of activities that are included, the competitive aspects, and the system of earning points. The author strongly encourages everyone to participate. _________ Title>NHC2:Tall Stacks '92 Special-Event Station Author>DiGennaro, Paula - KA8HQJ Source>QST Jun 1993 Abstract>A Special-Event ham station aboard a river steamer during the "TAll Stacks" celebration. Digest>The author and her husband, Nelson, WB8VUU, established a 2-meter station aboard the Mississippi Queen paddle-wheel steamer during the Tall Stacks week-end on the Ohio River in 1992. They were permitted to set up their equipment on the sun-deck (top deck of the boat) on Sunday from 10:30 a.m. to 5:30 p.m. and arranged to use the Fairfield Amateur Radio Association's repeater at 145.19 MHz. It is linked with other repeaters and offers coverage as far north as the Ohio-Michigan border, east to West Virginia, west to the Indiana-Illinois border, and south as far as southern Tennessee. The operating time included the period of the great steamboat race between their ship and the Belle of St. Louis! The Mississippi Queen won the race. Their opertion was highly successful and they made a total of 210 contacts over 5-1/2 hours of operating, averaging 38 contacts per hour. _________ Title>NHC3:Pack-in-the-Box Author>Levin, John - KM6JV Source>QST Jun 1993 Abstract>Describes a complete 2-meter packet station carried in a small cardboard box while traveling. Digest>Mr. Levin is a 2-meter packet enthusiast and wants to be able to take a packet station with him when he travels. Accordingly, he assembled a complete 2-meter packet station in a small cardboard box that he can easily carry with him. His transceiver is a Yaesu FT-470 HT. As a terminal he uses a lap-top computer, a Sharp Wizard Electronic Organizer. In addition, he bought an RS-232 signal-level converter, which is a standard accessory for the Wizard, and a PacComm Handi-Packet TNC. He packed them all in a cardboard box, each fastened down with adhesive-backed Velcro or tie-wraps. He reports that he is very pleased with the way the system which he calls "Pack-in-the-Box" has performed. _________ Title>NHC4:Your Information Connection: The ARRL BBS Author>Ford, Steve - WB8IMY Source>QST Jun 1993, pp. 60-62 Abstract>A description of the resources available from the ARRL BBS, and how to access them. Digest>ARRL maintains a telephone bulletin-board system (BBS), named Hiram. It can be accessed by telephone any time of day or night through the use of a telephone modem and computer. The computer must contain a terminal program that makes it possible for one to exchange information through the modem and telephone line with other computers. Hiram can communicate at any speed from 300 to 14,400 baud, or bits per second. Through the BBS, a caller can exchange messages with anyone at ARRL Headquarters, or download (that is, obtain a copy of) any of more than 500 files that the ARRL makes available, and to which they are adding all the time. Among the files available are packet software, W1AW bulletins, orbital elements for satellites, satellite images, a wide variety of software designed for amateur use, and many, many, other items. _________ Title>NHC5:The Doctor is IN Author>Various Source>QST Jun 1993, p. 63 Abstract>Questions and answers on topics of primary interest to newcomers. This month's column discusses WAS and WAC awards; replacing a monochrome monitor with a VGA color monitor on a computer; "custom" call signs; the difference between SSTV and FSTV; working the Oscar 13 satellite; and soldering PL-259 coax cable connectors. ------------------------------------------------------------------------ RADIO TIPS (RT) These are short items, scattered among the articles in the NEW HAM COMPANION section. _________ Title>RT1:What's Your RST? Author>Ford, Steve - WB8IMY Source>QST Jun 93, p. 62 Abstract>A description of the RST method of reporting c.w. received signal characteristics. Digest>The RST scales are as follows: Readability: 1 - Unreadable 2 - Barely readable 3 - Readable with considerable difficulty 4 - Readable with almost no difficulty 5 - Perfectly readable Signal Strength: 1 - Faint, barely perceptible 2 - Very weak 3 - Weak 4 - Fair 5 - Fairly good 6 - Good 7 - Moderate 8 - Strong 9 - Extremely strong Tone 1 - Very rough and broad 2 - Very rough 3 - Rough 4 - Slightly rough 5 - Noticeable hum or buzz 6 - Hum or buzz just audible 7 - Near perfect tone; slight hum or buzz 8 - Near perfect tone; trace of hum or buzz 9 - Perfect tone ------------------------------------------------------------------------ GENERAL INTEREST ARTICLES _________ Title>GI1:Roving for VHF Gold in the Colorado Rockies Author>Nerger, Paul - KF8EY Source>QST Jun 1993, pp. 21-23 Abstract>Operating in the Colorado mountains during the VHF QSO Party. Digest>This is a story of the experiences that the author and a ham friend (Bob Witte, KB0CY) had while roving around the mountains in southwestern Colorado during the June VHF QSO Party. Their activities were in the "Rover" category in Grid Squares DM-57 and DM-67. The pair took three antennas with them, a 3-element 6-meter beam, an 11-element 2-meter beam, and a 16-element beam for 432 MHz. They had power amplifiers giving them from 100 to 160 watts on all three bands and their vehicle was a Jeep. Their only power supply was the Jeep's battery which they kept charged by running the engine about once per hour. They moved to several different places, mainly high mountain passes at altitudes from 10,000 to over 12,000 feet above sea level. In all, they made some 60 contacts during the two days and gave many contesters contacts in grid squares that otherwise would have been difficult to contact. They both enjoyed themselves thoroughly. _________ Title>GI2:The Rise of Frequency Modulation Author>Hyder, Harry R. - W7IV Source>QST Jun 1993, pp. 42-45 Abstract>The story of Edwin Armstrong's development of FM broadcasting. Digest>This article recounts the story of the development of frequency modulation by Edwin H. Armstrong during the 1930's. In the early days of radio broadcasting, amplitude modulation was universally used. The biggest problem facing listeners was the high noise-level and fading that accompanied reception. Armstrong realized that a frequency- modulated signal could be nearly noise-free and set about in the early 1930's to develop such a system. He succeeded and formed a company to build the first FM broadcasting station and also to manufacture receivers. The author confines his article to a discussion of the system that Armstrong developed, its growth in popularity as a broadcasting medium, and its use in ham radio. _________ Title>GI3:Radio is My Passport Author>Sharma, Milind - VU2GOC Source>QST Jun 1993 Abstract>A student from India uses ham radio to link with home. Digest:This is a story written by a young lady from India who is a student at Lester Pearson College in Victoria, British Columbia. She had gotten the equivalent of a General Class amateur license in India at age 14. At college in Canada, she became very active in the college's ham club and introduced many other foreign students to the hobby. She recounts how ham radio has helped many students overcome some of their homesickness by allowing them to talk, in their own language, to friends and relatives at home. _________ Title>GI4:Phase 3D: A Satellite for All - Part 2 Author>Jansson, Dick - WD4FAB and Tynan, Bill - W3XO Source>QST Jun 1993 Abstract>Completes the two-part article by describing how the satellite will operate and how it can be used by all hams. Its primary purpose will be as a multiple transponder on several bands simultaneously. It will be fully usable by relatively modest ground stations. Digest:This is the second and final part to this article. In it, the authors discuss some of the design goals and specifications according to which the satellite is now being designed and built. The primary goal that everyone wants to achieve is to make the new satellite one that can be used by all hams. It should be possible to use it with relatively modest equipment used in ways that can be readily understood by all amateurs. As has been the case with the other "high-altitude birds", and many of the lower satellites that have been launched in the past, the primary functions of this satellite will be as transponders. That is, a ham on earth will be able to transmit to the satellite on one frequency band and the satellite will re-transmit that same signal on a different band back to earth. Hence, it will be possible for any two hams within sighting range of the satellite to communicate with each other. The satellite will carry high-powered transmitters, high-gain antennas, and highly sensitive receivers. The antennas will always be beamed at the earth. The high-gain antennas will make it possible for the satellite to receive signals from modest transmitters and re- transmit them with sufficient effective radiated power to make it possible for modest receiving antennas and gear to capture them. The 3D bird will carry antennas and transmitters to transmit (down-link) in the 144 MHz. ("V-Band"), 430 MHz. ("U-Band"), 2.4 GHz. ("S-Band"), and 10.5 GHz. ("X-Band"). Receiving (up-link) will be done in the 144 MHz. ("V-Band"), 430 MHz. ("U-Band"), 1.26 GHz. ("L-Band"), and 5.6 GHz. ("C-Band"). There will be computer logic and switching to implement almost any of the combinations of those bands for an uplink-downlink mode of operation. In the beginning, no doubt the V- and U-Bands will be the most popular. But the satellite is being designed for a long life and future operations. There is little doubt that, in the 21st Century, the microwave bands will become more and more popular and the satellite will be ready! Design engineering and manufacturing of such a sophisticated bird is requiring state-of-the-art technology. All power will be supplied by solar cells and the satellite will carry 44 square-feet of solar arrays which will produce 730 watts of power in the beginning. After 10 years of life in orbit, it is expected that the power available will be reduced by 40 percent, but that will still leave enough for the satellite to perform its assigned mission. To keep the bird oriented so that the solar cells are always facing the sun and the antennas facing the earth requires engineering of a high order. The computer will be able to turn the satellite in all directions by the use of reaction wheels. These are wheels, like those in gyroscopes, which rotate continuously and, when a wheel is accelerated or decelerated, its housing creates a reaction torque that will push the satellite in space in a controlled way. The high-gain antennas also present severe design problems. Long Yagi antennas with boom lengths sufficient to produce the necessary gain are out of the question when it is considered that they would have to be folded up and packed into a rocket, later to be discharged into space and unfolded in a reliable and controlled manner. Instead, a broad, flat, circular antenna called the "short-backfire" antenna is being built to do the job. This entire project is one that will benefit every radio amateur in every country where they exist. Its success will become a matter of pride to every ham. It needs our support. Funds are very short and every ham is encouraged to make a contribution. Address them to Phase 3D Fund, c/o AMSAT-NA, P.O. Box 27, Washington, D.C. 20044. AMSAT-NA is a non-profit organization and U.S. taxpayers may be able to claim a deduction for their contribution. ----------------------------------------------------------------