Thank you, Ed. You have captured my fear; "bill after bill added up." I have some more work to do to answer your diagnosis questions. However, here is what I can answer:
1. Exactly what does that noise sound like? Slow click, very fast tick-tick-tick, buzzer, or more like random static? There is the tick-tick but also the garble mixed in. My guess is that the RF noise has an amplitude that is triggering the squelch (listen to me sounding like I know what I am talking about). 2. Does it change frequency with engine speed? I don't know. I haven't try that but I will. 3. Does it make the noise with both mags, each tested separately? (John Savot's question) I need to try this since it may narrow the search for the problem. 4. When the engine is running at a fair speed (i.e. 2,000 rpm), if you switch the mags to off does the noise go away instantly or does it continue for a few seconds as the engine spins down? I have to try this one. It was not one of the things I thought of checking. 5. Does the handheld still have this problem with the engine running and the master switch off? I don't think that I turned the master switch off when I tested with the handheld radio. I will specific test this. 6. When you tested with the handheld, was it running on batteries or plugged into aircraft power? (If it was on airplane power, then test it on battery power with rubber ducky antenna.) The handheld radio was operating off batteries and it's own rubber ducky antenna. I did notice that I got difference levels of interference when I move the radio around the cabin. Obviously the interference was less when I put the radio on the seat or toward the back of the cabin. I will do some more tests and try to locate an expert. Unfortunately, the interference is bad enough that I can't trust flying. I had trouble hearing the taxi instructions yesterday. I got it the second time, but I decided this was not a safe way to fly. Thanks. Frank Nelson N51DV - 415C TOA --- In [email protected], "Ed Burkhead" <e...@...> wrote: > > > Frank, > > My experience was that I had mechanic after mechanic work on eliminating my > radio noise. They did the things they knew to do. Bill after bill added up > to about $2k-$3k in today's money. > > Finally, I found an avionics shop, bit the bullet, flew the plane there and > left it. I got a call the next work day saying it was fixed. > > When I went to get it, he wouldn't take any money because the solution was > so trivial the expert took only a few minutes to diagnose and fix the > problem. (Naturally, he got LOTS of word of mouth recommendations from me.) > > A real avionics expert can be worth the cost even though you will probably > not get a deal like mine. > > It can be better to pay for a real expert rather than pay for groping around > attempts by non-experts. > > Maybe we can help. More information helps a lot. Here are a few diagnosis > questions I'd think of: > 1. Exactly what does that noise sound like? Slow click, very fast > tick-tick-tick, buzzer, or more like random static? > 2. Does it change frequency with engine speed? > 3. Does it make the noise with both mags, each tested separately? (John > Savot's question) > 4. When the engine is running at a fair speed (i.e. 2,000 rpm), if you > switch the mags to off does the noise go away instantly or does it continue > for a few seconds as the engine spins down? > 5. Does the handheld still have this problem with the engine running and > the master switch off? > 6. When you tested with the handheld, was it running on batteries or > plugged into aircraft power? (If it was on airplane power, then test it > on battery power with rubber ducky antenna.) > > This one can provide hours and hours of ?fun?! > > Ed >
