Radio Static when Receiving. Progressively worse through the flight

Plugging headset out and back in is a clue. If it is related to that action, then anything between (and including) headset and radio is potentially at fault. I would start by disconnecting all headsets except one, and try that. You may have one headset that is malfunctioning.

You have an audio panel? Try turning it off, which should bypass the audio right through it.
 
Had this same issue in my Cherokee, it was my headset.

Switched it out for my wife's and it all went away.
 
@cowtowner 's post reminded me of a problem I had just like that. Ended up being a loose jack in the rear of the plane.
 
@cowtowner 's post reminded me of a problem I had just like that. Ended up being a loose jack in the rear of the plane.
It does sound like a capacitor may be failing and that unplugging the headset could be allowing a reset of sorts in the audio/intercom system.

But I more suspect what you have noted i.e. a jack may be loose and, if so, the insulating washer between the jack and the metal panel (if built that way) could be failing and causing a ground loop to develop. Pretty easy to check and easy enough to repair if that is the case.
 
Interesting. I'm having a very similar issue that's gotten progressively worse over the last month or two, except my issue only happens on transmission. I can always receive just fine.
At low power settings (~ <=15" MP) or on the ground, it's never an issue. But somehow after flying for a little bit it gets worse and worse. When I transmit I can hear an obnoxious broken static-y sound, and ATC receives it the same.
It happens on both comm units, both pilot/copilot jacks, both PTT buttons, both my bose/zulu headsets, alternator on/off. Nothing seems to reliably solve it except lower power settings or just being on the ground.

It's gotten crappy enough where now I'm scheduled to bring it in for maintenance next week to have a professional take a look at it... It's also made me always keep my backup handheld radio at the ready and test it more frequently.
 
I have had what seems like the same or similar problem. This frustrating and hard to figure out problem had the progressive sound starting or worsening after the radios have been on for 15 min more or less when listening with headsets. Also, I noted that if I pushed the front of the Garmin 340 audio panel, that altered the sound some of the time. Also, when I used the aircraft speaker without headset, the speaker sound had no noise. After replacing the audio panel with another which DID NOT eliminate the problem, I finally got my avionics tech to consider less obvious problems related to the audio panel. The investigation found that the connectors on the back of the audio panel box were loosened and backing away. Once tightened, problems were eliminated.
I hope this is helpful.
Good Luck.
 
I had bad /noisey reception.Read up on ground loops-make sure all headset jacks [ground loops] are mounted with non metalic washers.It solved my problem.
 
Has the OP tried checking the mags in flight to see if the noise disappears? The frequency of the static implies a magneto condenser going bad.
 
Interesting. I'm having a very similar issue that's gotten progressively worse over the last month or two, except my issue only happens on transmission. I can always receive just fine.
At low power settings (~ <=15" MP) or on the ground, it's never an issue. But somehow after flying for a little bit it gets worse and worse. When I transmit I can hear an obnoxious broken static-y sound, and ATC receives it the same.
It happens on both comm units, both pilot/copilot jacks, both PTT buttons, both my bose/zulu headsets, alternator on/off. Nothing seems to reliably solve it except lower power settings or just being on the ground.

It's gotten crappy enough where now I'm scheduled to bring it in for maintenance next week to have a professional take a look at it... It's also made me always keep my backup handheld radio at the ready and test it more frequently.

I’m having the same issue but appears to be related to com1. I’ve resorted to using com2 as my primary, generally without any sign of the issue. However on my most recent flight, while monitoring CTAF for destination airport on com1 and replying to ATC on com2, the same noisy xmit issue appeared. I switched off the monitoring of com1 on the audio panel and retransmitted on com2 without issue.

A&P and avionics guy haven’t identified issue but are thinking about trouble shooting steps I might try in the air since it doesn’t reproduce on the ground.


Sent from my iPhone using Tapatalk
 
but are thinking about trouble shooting steps I might try in the air since it doesn’t reproduce on the ground.
If they have tried all possible checks with no duplication on the ground, I usually start by swapped antennas/coaxes for in flight checks. In some cases this can be done behind the radio rack if you have coax pigtails from the racks.
 
I’m having the same issue but appears to be related to com1. I’ve resorted to using com2 as my primary, generally without any sign of the issue. However on my most recent flight, while monitoring CTAF for destination airport on com1 and replying to ATC on com2, the same noisy xmit issue appeared. I switched off the monitoring of com1 on the audio panel and retransmitted on com2 without issue.

A&P and avionics guy haven’t identified issue but are thinking about trouble shooting steps I might try in the air since it doesn’t reproduce on the ground.


Sent from my iPhone using Tapatalk

Update: A&P is pretty sure he fixed my issue today. They found a "very dirty transmit selector" on the audio panel. They were able to replicate the issue I was experiencing while on the ground and then fixed it. I haven't picked up the plane to verify it solves the problem but the A&P sounds confident. Perhaps something to check if you're still experiencing the same issue?
 
Update: A&P is pretty sure he fixed my issue today. They found a "very dirty transmit selector" on the audio panel. They were able to replicate the issue I was experiencing while on the ground and then fixed it. I haven't picked up the plane to verify it solves the problem but the A&P sounds confident. Perhaps something to check if you're still experiencing the same issue?

Sounds like good news, but what is a "transmit selector?" Is that a button in your audio panel?
 
Yeah, flight tested it and now it's fixed.

It's the dial, the actual selector where I click between comm1+2. I have a manual dial on my ancient audio panel. That was apparently super dirty. Once cleaned it now is crystal clear.

Thankfully they were able to replicate on the ground by switching between comms while trying to transmit and that helped them isolate the problem.
 
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