Radio Intermittent Transmission problem

[patterson]

My comm radio has developed a propensity to stop transmitting, then it will work again without warning and without turning it on/off or any changes to the circuit. When I want to call the tower, it may....or may not transmit. When it works it works fine. When it doesn't, it receives fine, just won't transmit. Any ideas on how I can narrow this down? I've checked the connections.
Thanks
Ron

[akarmy]

I had a similar issue that ended up being the PTT wire rubbing on the firewall structure which caused it to cycle the intercom PTT off and on so fast you couldn't transmit on the radio. The diagnosis was clear when you could see the transmit light flicker without pushing a button. May not be applicable to your situation, but you never know. Checking the intercom connections to the radio and that the wires are not rubbing on anything is one area to look at.

[GeneL]

Check your push to talk circuit. Button should ground circuit.

[BobTurner]

Try easy things first. Spray some contact cleaner into your PTT switch, see if problem goes away.

[N526JS]

Doesn't your radio have an Xmit symbol or light that comes on while transmitting? That will narrow down the the investigation, especially with regards to the PTT switch.

[Remag]

I had a similar problem. Turned out to be a loose wire in my Lightspeed Zulu headset. Lightspeed fixted it under warranty. Seems to be a common problem.

[dougknight]

a friend had the same symptoms in his 6A after installing a new radio (A-210). Long story short it seems he had run the new comm antenna wire in the same proximity as his transponder antenna wire. The transponder was blocking the comm signal when it was sending receiving making it intermittent. Turn your transponder off and see if your symptoms don't go away.

doug

[patterson]

Thank you all for your ideas on where my problem might lie. I'll try them all and report back when I figure it out.
Ron