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Linda The mag noise filters cannot be used with all types of mags. Please consult the list of approved magnetos that comes with the noise filters, before installing them. I have slick magnetos and had to return some mag filters I bought at Wag Aero. My A&P IA was not comfortable because the slicks were not on the list of approved magnetos for the filters. The manufacturer of the filter conformed indeed that they could not be used with slicks. The filters are no more than capacitors between the P lead and ground and for some specific magnetos, they can affect the timing. Eliacim Cortes N87071 > ----[Please read http://ercoupers.com/disclaimer.htm before following any > advice in this forum.]---- > > > I'm hoping the list can help me with a radio transmitting problem. > > I am a 3-month-new owner of an Ercoupe 415-C. My radio is an old ARC > Cessna 300 Nav Com. It came to me with the VOR inoperative, but the > radio sounded great. > > But recently, it has developed a transmitting problem. Typically, before > starting the engine, if I do a radio check, Ground Control says my > transmission is either "fine" or "on the weak side, but readable." But > it deteriorates from there: once I've done a couple of touch-n-go > landings, the tower is asking me to repeat. After 2 more, they're > telling me my transmissions have become almost unreadable. For > shorthand, below, I will call this sequence the "Same Problem." > > Problems first arose after I took off from Torrance, and was crossing > over the LAX Special Flight Rules Area, and another plane told me I was > unreadable, although I heard him fine. As I flew into Camarillo, I > think I lost all sound for about 5 seconds (behind a hill??), but it > came back, and I had no problem with the landing. However, on taxiing > to depart, Camarillo Ground could not hear me at all, although they were > loud & clear to me. When I changed to my back-up headset, they said > transmission was loud and clear, so I flew out. I had no complaints > from Torrance Tower when I landed back home. > > Then an acquaintance who is an avionics man with Delta came out and > checked that headset against his, and said he thought the mic tip had > gone bad, so I've sent it in to Telex-Echelon to check it. > > However, meanwhile, the next time I tried to fly, using the *backup* > headset, the pattern of "Same Problem" (deteriorating transmissions) > began. > > So I took it to an A&P, who first pulled the old Cessna 300 radio out of > its tray, cleaned all the connections, and put it back. I did a few > touch-n-goes, and the "Same Problem" developed. I landed and taxied > back to his hanger, shut off the engine, and gave him my hand-held > ICOM. He had me tune to 123.45 and talk to him: he said the > transmitting sounded fine with the engine off. Then I did a radio check > (engine still off) with Ground Control, and they said I sounded fine > (even though we were between hangars). So that caused him to say, "It > probably isn't the radio itself." We're kinda suspecting some engine or > ignition noise interference. > > The next day, he checked & cleaned all the grounds, and checked the mag > noise filters for tightness; said one seemed a bit loose & tightened > it. I flew it again, but got Same Problem, same as the day before. > > Today, an acquaintance (avionics man at Delta) came out with an ohmmeter > (sp?), pulled the radio from the tray, checked the antenna wire from > behind the tray, had me wiggle the antenna while he did this, and said > it's probably not the antenna wiring. He looked around the engine > compartment, found 1 wire whose covering was the old kind and crumbled > for about an inch; he taped that up. > > All I've heard of that is left to check is to replace the mag noise > filters, and see if that solves it. I've ordered 2 new ones and if I > get the Same Problem the next time I fly, I will switch to using a > hand-held Nav-Com and will pick the mag noise filters up from Spruce on > Tuesday. > > If new mag noise filters don't solve it, are there any other sources of > this kind of problem that I should check out before concluding I need to > buy a new radio? > > Oh -- I'm ignorant of electronics, and nearly so about aircraft engines > (though learning fast, of necessity) so if you reply, please explain > acronyms or other verbal short-hand so you don't lose me in the dust ;-) > Thank you! > > Linda > Ercoupe N3437H > > > ============================================================================== > To leave this forum go to: http://ercoupers.com/lists.htm > > > > ============================================================================== To leave this forum go to: http://ercoupers.com/lists.htm
