Radio Technique
WHAT WE NEED is a basic Helicopter radio! Based on a sample of three observations (the Nats, the Long Island Hover Lovers, and the 8th Annual East Coast Helicopter Championships), I got the impression that the preferred Helicopter radio going into the 1983 Contest Season was the Circus Apollo D6C-4SHM system ("Radio Technique," October 1982 MA). That system literally defined the term "Basic Helicopter Radio," since it offered linear electronic Tail Rotor mixing and a trimmable, mixed (fifth servo) Collective control, the price was right, and it entered the market at the same time as the Kraft gyro. Many were sold to beginners, who enjoyed early success when they used them with well-developed modern Helicopter kits. I credit better Helicopter kits, the Apollo radio system, and the Kraft gyro for much of the recent growth of RC Helicopter activity.
Radio Technique
A LOT has happened in and around my personal life this past month: Lee Anne and Corey informed me of a new grandchild in production. Geoffrey visited for a few days (his job usually keeps him in the Inter-mountain West), Chris announced his engagement to Terry; my mother-in-law, Anne, who lived with me, died; two blizzards fell on Long Island. I've helped develop "Sky Day" at a local college, helped a friend put together an article on his plane (which should appear in this magazine soon), gave talks at a couple of local clubs, and put off the Income Tax to the last minute. It should come as no surprise, then, when I say that I haven't finished the Helicopter (a Baron 20, powered with an OS Wankel- I talked about it last month), so I can't tell you how it flies inverted.
Radio Technique
BUILD ME. I'll bet that the worst RFI (radio-frequency interference) comes from the source you consider least. Letters I've received, and conversations I've had with other modelers, lead me to suggest that the most devastating interference comes from transmitters left turned ON when they should be turned OFF. If that is true, then what every impound operator really needs is a simple, reliable tool for discovering such oversights. Enter John Lange, AMA's DFC (District Frequency Coordinator) -at-large, bearing his "RF Wand," a copy of which he has donated to the AMA along with permission to publish the following description and instructions. Its value and use were demonstrated at the LSF tournament and at the FAI Sailplane trials in the summer of 1983, where John used it to catch a few mistakes and to show that a man who was crying "interference" actually was suffering the effects of his own loose transmitter antenna! (When John had the man shake his transmitter, both of them could hear his signal cutting in and out.)
Radio Technique
SRF. SRF. Study those letters-you'll be hearing a lot about them in the future! They stand for Switchable Radio Frequency. This month, I'm going to address the subject: What about Kraft's synthesized RF system? Who needs a synthesized RF generator? Mainly, the RC manufacturers need it, to keep prices down. The synthesizer uses one universal crystal and a simple computer to replace 160 unique crystals (80 for transmitters, 80 for receivers). Soon, everyone will be making SRF radios. Look at the economics.
A Flag for SRF Radios
SWITCHABLE radio frequency (SRF) RC systems have been with us for some time. In the 1960s, crystal swapping on 27 MHz became legal and was commonly used in such activities as RC car and boat racing, where it is still used and considered a necessity. Crystal-swapping is still legal on 27 MHz, today. Around 1970 Kraft, then Heathkit, began selling radios that included a switch to select either of two built-in 72 MHz crystals. Transmitter crystal swapping on 72 MHz was not legal (it still isn't) but the factory-installed switching was, and still is, legal.
