Ok, I have asked and been given AN explination, but in thinking about it: What was said doesn't quite work for me.
No offence to the person who said it.
Scenario:
Jab' with radio. My head set.
When in flight and I talk, it is distorted with a lot of background noise and "pulsing".
It was said this is called "motor boating" and it is because the altermeter is not big/strong enogh to handle the load. Sounds plausible.
But let's look at some things which I feel/think fail that idea:
I am flying, not idling. The revs are at about 2700, the voltage is 14.4 and there is little else on. IE: No landing lights, no NAV lights, no beacon, no strobes. Just the radio, Xponder, EFIS and HSI. Oh, ok, and my GPS plugged in the AUX socket.
Now, fair enough voltage and current are different things, but if the alternator wasn't cutting it, wouldn't the voltage also be fluctuating? And there is a battery in the equation to "fill in the gaps" if the alternator wasn't producing enough output.
Of course throughout this the CHARGE light is NOT glowing. It does at idle.
So who has any other ideas? Yes, I know that usually with that kind of problem the power supply is the first and major suspect. But given the voltage (inndicated) is 14.4 at the time, it sort of shoots that idea dead.
At idle, the voltage goes down to 11.9/what ever. I can clearly see that with revs/power the voltage increases, which makes sense.
Anyone?