GMA 240 shutdown. Heat?

Folks,

I have a Garmin GMA 240 audio panel, and about a year ago, on a cross country I got to chatting with an ATC guy at Fr. Leonard Wood. It was during Covid when there was very little aviating going on and he was bored. Great guy though!

Anyway, after maybe 20 minutes or so talking, the audio panel quit. After a short while it came back though and didn't give me any problems after.

Wondering if anyone knows if there is built in automatic resetting thermal protection built into the unit.

I'm going to upgrade audio panels and don't want to sell it if it's got a real problem.

Are you sure it was the audio panel? These things generate very little heat, especially if there’s no loudspeaker in use. Did you turn it off? This should have put you in ‘fail-safe’ mode, with the pilot directly connected to com 1, by-passing the 240. OTOH, a lot of continuous transmissions do heat up coms, and many of them will reduce power and/or shut down if the output stage gets too warm. As to your question: it is not normal for an audio panel to shut down, no matter how much you use it.

BobTurner said:

Are you sure it was the audio panel? These things generate very little heat, especially if there’s no loudspeaker in use. Did you turn it off? This should have put you in ‘fail-safe’ mode, with the pilot directly connected to com 1, by-passing the 240. OTOH, a lot of continuous transmissions do heat up coms, and many of them will reduce power and/or shut down if the output stage gets too warm. As to your question: it is not normal for an audio panel to shut down, no matter how much you use it.

Click to expand...

THAT, is a VERY good question? The button lights never went out, so it's not like all the power in the unit shut down. And to tell you the truth, I don't recall if it was just my transmissions that were gone or if it was both transmission AND reception.

At any rate, it's been working fine since, so maybe I just shouldn't worry about it. Thanks Bob.

Too hot

Yep. Both the HF's and VHF's in the Boeings I flew had a 30-sec limit for continuous transmissions. Sorry...no yakkin' allowed!!

The GTNs and GTRs possibly other also have a "stuck mic" feature -- Transmissions > ~30 seconds will throw an alert message and cease transmission.