TX lights flashing during flight, solid on ground.

[gnuse]

On the ground with engine running or not running, both radios transmit with a solid TX indicator. In flight either radio shows blinking TX when PTT is pulled and there is no transmission.

I know it is difficult to diagnose over VAF, but I would appreciate any advice as to where to look. PMA4000, Infinity stick grip (PTT), Garmin 430, KX125.

I don't know enough about wiring to understand what I might be looking for. Yesterday I removed flooring and "wiggled" stick, wire coming from stick and heard/saw no interruption of TX.

 

[Snowflake]

You've got something tripping the transmit on both radios, so it has to be something that both radios can "see" on the circuit at the same time. I'm guessing the Infinity grip PTT is wired to something that switches your PTT signal between the two radios, either an audio panel or a multi-pole switch of some kind. If it's an audio panel, can you unplug the audio panel briefly and see if the TX stops?

 

[Raymo]

Your switching between radios should happen within the PMA4000, which would be the place to start, as Rob suggested.

If it is on its own circuit pull its fuse/breaker and see if the issue goes away.

Is this a new build or a new problem?

 

[gnuse]

Sorry to not be more clear.

The intermittent TX indication happens on which ever of the two radios is selected, not both at same time. This is not a new build, it is a new problem.

 

[gnuse]

Problem solved!!

I am leaving this message in case anyone else has a similar problem.

Amazing to me, the problem was solved with a simple application of contact cleaner to the push to talk switch. TX is clear as a bell and steady on each radio when the PTT switch is pulled.