Originally Posted by
jtpitkin06
The first place to look for your noise is at the receiver to make sure your audio grounds are all connected at the same place close to the receiver. All audio grounds must come to “Mecca” (the receiver or chassis ground very close to the receiver). Do not think grounding to a convenient spot on the frame or to a grounding bar on the DC electrical system is the same. It isn’t.
All audio jacks and mic jacks must be mounted with shouldered isolation washers to prevent the jack body from grounding to the frame.
Check audio jacks are connected when you check the grounds between them. They have Mecca in common. The tips should not be connected if you are running them through an intercom with separate volume controls.