This is not a big problem since I can not hear the hum when in flight, but I thought someone might be able to tell me how to stop it.  I have the Renesis and I am using the stock capacitor that is attached to the engine.  When I turn on the alternator, there is a slight buzzing hum that appears in the headset and the frequency goes up and down with the engine.  It is pretty obviously the alternator I think.

Does anyone have any suggestions?

Bill B