Radio Technique
OLD FRIEND REVISITED. I first reported on the Accu-Tach 2 in the February, 1985 issue of Model Aviation. It is an instrument which combines a digital voltmeter, ammeter, and tachometer in one light and handy package. My Accu-Tach 2 has provided excellent service for three years and is an essential part of my field kit. The manufacturer of this device is now the Norcal Avionics Div. of A-B Tech Inc., 5689 Glasgow, Troy, MI 48098; telephone (313) 828-8210. Accu-Tach 2A adds a remote tachometer probe, clip leads, and a handy zipper pouch to the catalog. A couple of labels have been added to define the function of the Tachometer/Voltmeter selector switch and of the built-in tachometer sensor; otherwise, the the Accu-Tach remains its old, dependable self.
Radio Technique
20 Jan 1985 Mr. George M. Myers AMA Dist. #2 Frequency Coordinator Dear Mr. Myers This note is to bring to your attention a situation in which you might take an interest. During May and June of 1984, I experienced severe interference problems on three different occasions, while using RC44 in western NY. I was flying a brandnew, seven-channel Airtronics Championship Series FM transmitter and receiver. Here's a description of the incidents: 1. Flying at Grand Island, about five miles north of Buffalo. Severe interference produced a crash. (At the time, I was not convinced of the interference, as the plane was new and not yet trimmed.)
Radio Technique
RC SYSTEM TESTING-the modified Myers/Aberle test procedure. Bob Aberle and I have modified our test procedure (which was originally published in my January 1986 column) slightly to match the 1988 situation. Our new test matrix is shown in Figure 4. The basic change has been transmitter is at least -50 dB at F0 ±20 kHz. OWBAM transmitters: We use George Steiner-modified Kraft synthesizer modules. These produce AM signals with sidebands of about -35 dB at F0 ±20 kHz with 500 Hz frequency accuracy. Unfortunately, they radiate slightly less power than do the NBFM synthesizers.
Radio Technique
CORRECTION: In response to a recommendation I made in the May 1987 column, Futaba says that the Conquest PCM is not narrow-band at this time. My recommendation was based on the result of testing one sample, which was very good. I apologize for misleading you. Made in the U.S.A. If someone were to ask me if there are any RC systems made in the U.S., I'd have to say that only Ace R/C, Inc., Cannon, and Royal Electronics remain to "show the flag" at this time, so far as I know. We hear that Ace R/C, Inc. is almost ready to release narrow-band AM and FM versions of the excellent Silver Seven systems. Bill Cannon has already shown his "SuperMicro" narrow-band system at the WRAM Show.
Radio Technique
Latest news from the 1988 RC frequency-utilization scene: A joint effort of the Radio Control Manufacturers Association (R/CMA) and the AMA is the certification of transmitters-new or frequency-changed. Sorry we can't show you these seals in color, but the upper one is gold, and the lower one is silver. A transmitter bearing a gold seal is certified narrow-band and can be used in AMA-sanctioned competition on the 12 "lower-band" channels (RC12-34). A transmitter bearing a silver seal is certified wideband and can be used in AMA-sanctioned competition only on the 10 "high-band" channels (RC38-56). There's quite a bit more information in this month's column.
