Need Radio Help Please

[Trappra]

Hi, need help with a radio issue in our 73 PA28-180. KA-134 audio panel, MX-170 nav/com #1, KX-170 nav/com #2

The MX-170 sounds like the squelch is constantly broken, background static. Transmits and receives fine, audio acceptable, but the background static is distracting. Swapping radios around and the problem follows the MX-170.
Took MX-170 to the shop and they find nothing wrong with it on the bench.



Tech verified wiring in A/C and found nothing wrong.

Any ideas?

Thanks

 

[bgmac]

 

[sanjiv]

 

[Tweety]

 

[sanjiv]

 

[Tweety]

 

[sanjiv]

 

[Trappra]