Radio Technique
BY WAY of review: There are four types of chargers for Ni-Cd batteries: Fast, Quick, Overnight, and Trickle. You can't know what kind of charger you are dealing with until you know two things: 1) The current the charger is putting into your battery. 2) The capacity of your battery's cells. The capacity of a cell is represented by C and measured in ampere-hours (or milliampere-hours for small cells). Charge rates in the range C/3 to C/6 define the Quick Charge situation. A Quick Charger will recharge a Ni-Cd pack in three to six hours. This rate is preferred by some engineers because it is faster than normal, yet produces less heat and presents less risk of damaging Ni-Cd cells by causing them to vent than does Fast Charging. The concern comes from the fact that the charging process is an electrochemical one which generates gas and is exothermic (it gives off heat). Both gas pressure and heat are a function of the charging rate, and maximum pressures and temperatures are determined, in part, by the way the cells are constructed. The higher the rate, the greater the risk.
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
Abstract: Battery and charger basics. CARING for NicadTM batteries - Part 1: There are as many kinds of advice about caring for NicadsTM (from here on we'11 call them Ni-Cds our usual editorial style. RMcM) as there are people selling battery-care devices. Some people recharge them only when the batteries are to be put to use. Other people charge them at regular intervals, whether they need it or not. Still other's keep them charged all the time with trickle chargers. Everybody succeeds. Who's right? The nickel-cadmium (Ni-Cd) cell is very tolerant of abuse and neglect, which makes it hard to define "wrong" answers. Its service life, measured in terms of available discharge/recharge cycles, exceeds our needs. "Rightness" is determined by the conditions under which the batteries are used. For example: When you pick up a portable telephone, you expect it to work immediately. Portable telephones have rechargeable batteries that are kept on a trickle charger.
RC in "The Great Land"
I SPENT THE SUMMER touring the Great Northwest (Alaska, British Columbia, and the Yukon Territory, Canada). I found many opportunities to indulge in our favorite hobby of RC flying, and this story tells you how to find them. The people I met were warm and friendly, the scenery was spectacular, and the weather was remarkably good, according to the people who live there. Actually, the normally rainy regions of southeast Alaska were experiencing a drought that hadn't been equaled since 1917. Most of the time was spent in sunshine (even at night), with daytime temperatures usually in the seventies (sometimes lower in rain) and nighttime lows dropping into the forties. Having only three or four hours of darkness in the 24-hour cycle, I found that I was active at least 18 hours a day. You can get a lot done in 18 hours.
WRAM Show '90
THIS YEAR'S edition of the Westchester Aero Modelers' annual midwinter show was bigger and better than ever, thanks to the efforts of show manager Frank Devore and the volunteer work by WRAM members. Though some familiar vendors, Futaba, JR, and MRC among them, were absent this year, virtually every room in the show was filled to overflowing. The directory listed 144 booths. Part video fair, part model aviation flea market, the WRAM Show reliably forecasts the coming technology in the RC industry. If this year's show had a theme, it would have to be the TOS-EPROM (Transmitter Operating System-Electrically Programmable Read-Only Memory). These systems have been around for a while in PCM sets, but this seems to be the year when they move into the design of every future set. The TOS-EPROM is what liberates a transmitter design from the rigidity of hardwired mixing and fixed control throws.
