Power inverter

[chrisktx]

More of an avionics question. Plane has Narco 12E and 12D Nav/coms. Static during transmission and reception, in the air. Com between pilots is fine. Garmin 340 audio panel (I've tried two). No problems on the ground. Tried new antenna, properly mounted, static wicks (half are new) in good shape, radios checked twice by The Radio Shop in Louisiana. Throttle settings, shutting down alternators, no changes. Just two headsets plugged in.

Both Nav/Com are 14V... I had an 'eureka' moment looking at pictures of them: maybe the power supply is bad? There must be some kind of step down onboard .
A Google search reveals King KA-39, or possibly Narco MP-11. Will verify what is onboard in a few days once back at the airport. Maybe it is as easy as a bad contact...

Any of you have issues with the inverters? What is a good replacement. KGS looks Cadillac but a little on the high end. I suspect something more modern will 'clean up' the power and make the radios happier...at least I want to factor that out. Maybe something upstream, the ships alternator controller bundle. Bad power in makes bad power out...

Any thoughts on 28V to 14V inverters and how they would effect the radios?