Radio Technique
ABOUT 900 TRANSMITTERS were processed for the 1985 Nats. Helicopter radios were predominantly PCM. Pattern radios were about 50% PCM and 50% other, with more AM than FM. Pylon and Sailplane were about 70% AM and very few PCM. Radios for Scale were about 85% old AM, with the balance split between new AM and FM. Interference problems were minimal. This was more due to the Contest Directors' planning than anything else. Jeff Troy had a 2 1/2-min. walk set up between the Sailplane launch site and the landing circles. Result: tired feed but no intermod problems. Pylon, Pattern, and Scale used frequency groupings that avoided the usual problems. Result: very few crashes, and practically all of them were due to pilot error, or were the result of some kind of failure.
Radio Technique
HAPPY NEW YEAR! During the 10 years I've been writing "RT," we have tested many radio systems. It has been a rare thing to encounter a defective or unusually-poor-performing system, regardless of price. In fact, some of the least expensive sets really have shown the best performances. Likewise, some of the highest-priced sets have produced the worst performances. The overall spread between best and worst has been small, once you discount the two or three real stinkers that we all know about (now). Reasoning that our previous test method may not have been showing us the most important differences, we retested a representative group of RC systems in an attempt to find a better test method. Table 1 shows the combinations of receivers and transmitters tested.
Radio Technique
MERRY CHRISTMAS. It seems a bit odd to be composing the Christmas column in the dog days of summer, but I am, with the temperature in the high eighties and the humidity likewise. The magazine business is a peculiar business. From time to time, it has been remarked (usually by someone unhappy with something I have written) that what I write in this column is just my own opinion, and not Official AMA Policy. That's right! Official AMA policy is obtained from the deliberations of the Executive Council. This column is a personal letter from me to you, and I want to keep it that way.
Radio Technique
MORE on Third-Order Intermodulation (3IM) avoidance. I have just received a very nice letter from Eldon Wilson, AMA 5247, of San Angelo, TX. I will share parts of it with you now. Mr. Wilson writes: ". . . you may wonder if your messages are ever considered. Let me relate how your `group frequency control' (July '85) worked. ". . . Our recent West Texas Fun Fly saw 93 transmitters impounded, of which 31 were on the old frequencies. On the new frequencies were 29 AM and 33 FM transmitters. In two days of flying, with four to six airplanes up at a time (75.640 is still being used), we logged 194 flights without a single case of interference or unexplained crash. Being one of the originals in RC (since 1950), I consider this a record.
Radio Technique
MORE ON MICRO RC. My comment on RC "insects" in the July issue has produced a surprising amount of mail. I've included a photo and two of the letters. If you are interested, you might write to these fellows. The first letter is from Harry Apoian (Apoians Model Aerodynamics, 27704 Saddle Road, Rolling Hills, CA 90274): "Enclosed photo is of my 1/14-size Pietenpol built in mid-1982. It was the result of a challenge posed by Larry Renger, master of small RC models. Larry supplied the Albin receiver and matching transmitter-and the dare to build a CO-2-powered RC model.
