Some static noise in my headset from the strobes-goes away when off

[don Freimark]

the noise stops when shut off. ANY ideas/suggestions greatly appreciated. I did find a new ground source and that did help alot.

 

[Bell206]

I did find a new ground source

You have a problem with the cable shielding. Might also have an issue with the aircraft ground plane if moving the light ground made it better. Have your mechanic check things over with a meter and should be a simple repair.

 

[TCABM]

You have a problem with the cable shielding. Might also have an issue with the aircraft ground plane if moving the light ground made it better. Have your mechanic check things over with a meter and should be a simple repair.

Or a really dirty anti-collision light. When we had our G5s installed, they installer added cheap strobing anti-collision lights that introduced strobing rf noise above 127.000. We changed those out and solved the noise problem.

 

[Kent Wien]

This super simple solution solved it for me:

Initially, my headset volume was turned all the way up. When I moved the sliders to the middle and turned the volume up on the radio and intercom the pulsating strobe noise went away!

Try that first.

 

[Dan Thomas]

The headset jacks are likely grounded to the airframe. They should be insulated from it, and the ground wire or shield should be grounded only at the radio rack. Old airplanes get some corrosion between the various joints, and ground currents such as those from the strobe look for easier paths. You end up with stray currents all through the airplane, and if the headset jacks are grounded to the panel, or if the "portable" intercom is screwed to the structure, those currents get into the audio circuitry and torment you. It's called a "ground loop" that has nothing to do with taildraggers.

 

[don Freimark]

I will check all replies-thanks for the response.

 

[Papa Pilot]

I had the "strobe squeal" as well. When I yanked all the headset wiring as part of my audio panel upgraded (needed to rewire as I was going from mono to stereo) I found the shield was being used as audio low as well as it being grounded to the airframe. I think that is why I was hearing the squeal.

On the rewire, I had a dedicated low going to the audio panel low pin and terminated the shield to the audio panel shield ground. I did not ground the shield at the jack. Squeal was totally eliminated.