Radio Technique
A LEADER RETIRES. Bob Aberle-past chairman of the AMA Frequency Committee, prolific model designer/builder/tester, and Technical Editor of Flying Models magazine for the past 15 years-has retired from writing for model magazines. He has not retired from working for a living as a manager in a large aerospace firm. Bob is one of my best friends, and I can testify that he put more time and effort each and every week into being FC chairman, writing, and photography than most people put into the jobs that pay their way through life. That's what filled a file cabinet at AMA HQ, and made his writing good enough to earn the McEntee medal from the WRAMs.
Radio Technique
A COUPLE of the clubs I met on my trip to Alaska were good enough to give me their patches, the appearance of which I will share with you now. Too bad this isn't in color, because some of these are real beauties. I haven't made a practice of collecting club patches, but these are special to me. Which reminds me: When you head north, take along something characteristic of your home area. People will be extending courtesies to you, and it is always nice to be able to reciprocate. Your club patch might suffice for the RCers you meet, but how about those who aren't RCers? Alaskans are readers (long winter nights, you know), so books about your home state, local histories, aviation histories, maybe a book about the company you work for, etc. might be just what you want. Try to bring something personal.
Radio Technique
BY WAY of review, there are four types of battery chargers for nickel-cadmium batteries: Fast (recharges in one hour or less), Quick (three to six hours), Overnight (10 to 15 hours) and Trickle (forever). Caring for Ni-Cd batteries: Part 4-Trickle chargers. Each type of charger has its own purpose. Trickle chargers keep a charged battery ready for immediate use. No "memory" will develop as a result of using a trickle charger. Batteries left idle will slowly discharge themselves. Since electrical charge is held by a chemical imbalance, and since chemical activity is a function of temperature, the warmer the storage temperature, the quicker the self-discharge. Conversely, storage at low temperature retards the chemical activity that causes self-discharge. Self-discharge at room temperature takes place at rates from C/50 to C/100 (C = rated cell capacity-e.g., 800 mAh). Another way to say it is that a fully charged battery will discharge itself completely in 50 to 100 days at room temperature (75ºF).
Radio Technique
Narrow-band systems available now: Airtronics, Inc. offers a new line of super narrow-band Gold label receivers for the U.S. and Canada. Airtronics is also the first manufacturer to submit independent laboratory test results to AMA HQ which demonstrate that both the new receiver and transmitter modules meet and/or exceed the AMA Guidelines for narrow band (1991 and later) performance. The best part is that these narrow-band receivers and matching transmitter modules are being made available to owners of existing wideband Airtronics equipment. (Isn't that what I predicted last year?)
Radio Technique
WHAT'S AHEAD? This is part two of the discussion I began last month: Bob Aberle, George Steiner, and I have seen, and tested in various ways, some DC (dual-conversion) Rx, including the new Airtronics receivers, Futaba 1024 PCM, Polk's Challenger 720, World's Expert, Ace, R/C's Model 91, and the old Kraft KPR-8FD. They show some interesting characteristics: 1) Adjacent-channel interference is insignificant to the new dual-conversion (DC) receivers. Gold-sticker transmitters at 20 kHz channel separation (the 1991 situation) have less effect on these new receivers than Silver-sticker transmitters at 40 kHz separation had on the old receivers (the 1983-1987 situation).
