Ok folks, now listen to this!!!!

I have been testing/tinkering/reading all about alternators... I turned on everything on the car as a test and heard a v-belt squeal when I turned on the rear window defrost...

So I tightened the alternator belt and now suddenly I am getting 48 amps at idle! That is 20 amps more output at idle from the alternator than I was getting!

So question: Can an alternator belt be "slipping" if it is not tight enough and you would not hear that "squeal"? (In my case perhaps slipping a little with a little load, and an all out squeal with a larger electrical load?)