So when the avionics are powered on (even with the engine off), I hear what I can only describe as an occasional very quick whistle sound. Like - very shot, higher pitched whistle that lasts like 1/2 of a second. It happens maybe randomly? Every several seconds or so? It’s also pretty faint volume wise.
It “feel” like this is something being simulated (like it’s supposed to be there). But what on earth is that?
Huh, ok. I didn’t mean the sound happens at the moment when I turn on avionics, it’s pretty much always happening, several times a minute. I meant to say that it only happens when the avionics are on. It does seem to be electronics related though since it only happens when they’re on. Strange.
Yeah, I’m not sure. Maybe I’m crazy (especially if no one else hears it lol). It’s not a one time thing (like something spinning up). It happens maybe 15 - 20 times per minute, as long as the avionics are powered up.
OK! It is the radio If I switch to com2, it goes away. It also goes away if I turn down the volume on com1. Thanks for the ideas all. It doesn’t bother me, it was more of a “hey, what the heck is that!?” sort of thing.