Has anyone cleaned the contacts on the femele side of your headphone jack, or the wiring from it to the radio?
Bill
From: Linda Abrams <[EMAIL PROTECTED]>
Reply-To: Linda Abrams <[EMAIL PROTECTED]>
To: [email protected]
Subject: [COUPERS-TECH] radio transmitting problem
Date: Thu, 21 Dec 2006 23:44:12 -0800
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>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
>
>
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