Leo Langston
Pre-takeoff checklist
- Joined
- Dec 30, 2016
- Messages
- 102
- Display Name
Display name:
llangston1
My Navion has 2 Narco MK-12D navcoms. Com1 has the GS and Com2 does not. Before my recent panel upgrade Com1 was my go to radio for all com and it worked fine. No noise or static what so ever. Com2 worked fine except at times the feedback side tone in the headset during transimssions was extremely loud and garbled compared to Com1. Now comes the panel upgrade. I keep the Narcos and add a PMA-450B audio panel. I also removed the straight rod antenna that was in front of my windshield and replaced with a bent whip antenna on the aft belly of the plane. So here’s my issue. Com1 now works and transmits fine but there is a loud constant static like no squelch. You basically can use it for ATIS but you can’t leave it selected on the 450B or it will drive you crazy. Of course com2 now works perfectly, no noise or static, crystal clear and no issues the sidetone feedback. Com 2 has become my go to radio. I also swapped the radios in the rack and both radios worked fine, no static, no noise. In the swapped position Pulling out the Vol knob on either radio turns off the auto squelch and pushing it in reactivates the squelch. In their unswapped positions pulling out the com 1 vol knob does nothing with the squelch. The loud static is still there. Com 2 Vol knob works fine with the auto squelch.
So where would one start trying to diagnose and remedy this issue? Yes I know I should replace the radios but they worked Ok before the panel upgrade so I would think this is an installation problem. The issue didn’t follow the radios when I swapped them, it went away and came back when I unswapped the radios.
So where would one start trying to diagnose and remedy this issue? Yes I know I should replace the radios but they worked Ok before the panel upgrade so I would think this is an installation problem. The issue didn’t follow the radios when I swapped them, it went away and came back when I unswapped the radios.