Originally Posted by bob888
I am having intermittent static in the radios that goes away when I switch off the alternator (Plane Power internally regulated). This is not the 'whine' typical of a bad diode but a harsh static loud enough to compromise radio communication. The question is...are these alternators repairable or need to just replace?
Static is a funny thing - before you throw the PP alternator into the trash, have a look at the isolation washers under the Mic & Phone jacks...maybe even replace them.
Here's my story - RV-7 started developing intermittent static after a few years in service. This static could be heard on top of received radio transmissions, flying VMC and transitioning in IMC would make it worse/followed turning on the PITOT HEAT; the noise would break the squelch limit on one of the radios.
The root cause, was slight cracking in the isolation washers at the microphone jack on co-pilot side. Some sort of ground-loop developed and the co-pilot mic was fuzzing into the audio system...