Question about Radio Interference


I know Ihad written some about this before. But this seems a little different, so I thought it would ok to ask this type of question again. Only this time it's a little different.
I've always been in question about Radio Interference. Where Ifly almost nobody is around for miles. Isay almost because there could be people, but the nearest flying club is several miles away. Back when Iwas learning to fly, my trainer's manual that stated that one should turn on the receiver and watch and listen to the control surfaces. I Also had a guy tell me, this is a bad idea. Anyways I check for interference by turning on my receiver. This year, I took two planes out, and turn on the recievers. Both set quietly. However today, Idid the same thing with the third plane, and it jumped around a little bit and then got quiet. Itried this several times, and it behaved the same each time. When I turn on the Transmitter and then the receiver, everything is ok. Then when Ido a range check, everything works ok too. What really puzzle's me is, last year I was testing things out on the same plane. The reciever went bad, and Ihad to buy a new radio system for the plane. The year before the radio system went bad Iwas getting the same results every time Itested for interference. I'm trying to determine if there is something in the airplane causing this phenomenon. It's a 72 Mhz Radio System by Hitec. The old Radio System was also 72 Mhz system by Hitec. Both are the same frequency.

Les


but the nearest flying club is several miles away.
Hi greg what Les explained is quite right and your equipment has demonstrated perfectly normal behavior and anytime only a receiver is on it will attempt to lock on to any stray RF out there commonly called noise.
One point that made me nervious though is your quoted comment and I gotta ask just how many miles is several?
You see anything less than three can indeed cause direct interferance. This indeed happened to our club several years ago when a few individuals decided to set up camp rather close and about a mile. They used mostly old swapmeet equipment and all attempts at diplomacy were shunned, Finally as the club president at the time I pushed for our club to abandon all but 2.4 and recommend only 2.4 just at our field. This as a protective measure for us and to prevent civil war.
There were a number of losses we experianced previously that we were able to confirm by scanner and visually with binoculars since they were active at the times.
John





Additional Information (I write this because it's a little confusing):
The old radio system I used in the U Can Do 3D is the same frequency and make as the New Radio System in the U Can Do 3D. The radio systems in both the Zlin 525 and the U Can Do 3D was always the same make and frequency.
My main Question
Why does the radio system in the U Can Do 3D jump around when the Transmitter is off, and the Radio System in the Zlin 526 does not?


John


