Fred McKenzie wrote:
Perhaps that is what I'm remembering. Now, if you use a filter to
eliminate the other sideband, the higher frequency components and the
carrier, don't you have a nearly identical remainder?

At that point I don't think you could tell the difference since there's no
longer any local phase reference (i.e., the carrier) to compare with. I
suppose this is why your SSB-AM rig is able to (somewhat) receive low
frequency (and thereby presumably narrowband) FM broadcasts; this is what
you were saying in your last post, correct?

I think we are in agreement that you can't recover FM modulation with
just an envelope detector

Yes, at least you can't recover a signal that directly corresponds to what
you transmitted. It does appear that you can recover the signal's square,
however, so this approach might be useful for, e.g., remote command
transmissions. (But probably just for the novelty of having said you did
it... since it's probably not much harder to build the slope detector you
describe!)

---Joel