I am getting noise feedback thru both headsets when I turn my intercom system on. The feedback does not start until I reach 1700 rpm on the engine and increases intensity as I increase engine rpm. I have played with all the setting in the radio and I have not been able to resolve the issue. If I operate the radio with out the intercom being turned on it works just fine. I have tried different headsets with the same problem occuring. What could be the issue?

Sounds like alternator whine getting into an unshieled wire in the intercom?

If there is any more information I can get for you to try and isolate this problem let me know and I will try to get it. Meanwhile, I will try what you have suggested so far.

Is it a whine that increases in pitch with RPM? Does it change if you turn the alternatior off?

It is not so much a whine, but more like the sound if you hold a cell phone next to a speaker during a call. It increases directly with RPM, e.g. 1700rpm produces slightly audible noise and full power produces maximum intensity sound.

I think I fixed it. I examined the wiring and found a wire end that was half covered with electrical tape and it had become a little exposed and might have been contacting the headphone plug. I recovered a few loose wires and I did not have time for a run up and check but hopefully tomorrow I will. Thanks for the info.