"Frank Dresser" wrote in message
...

"craigm" wrote in message
...

[snip]

You seem to believe that the positive peaks of the AM waveform represent
one
sideband and the negative peaks, the other. That is grossly incorrect.

If all you need to add is a diode to detect the opposite sideband, it
would
be cheap and easy for all radios to be sideband selectable with the flip
of
a switch. But you don't see that, ever wonder why?


[snip]

I read about such an AM stereo system in an old radio magazine. The
positive peaks of the envelope carried one channel, the negative peaks
carried the other channel. The idea was patented, but I doubt it was
developed to any extent. The normal "flywheel effect" of the L-C
filtering
would symmetrize the modulation envelope and destroy the stereo
seperation.
The higher the audio frequency, the the poorer the stereo seperation would
be. This system was completely compatable with normal AM radios but
adequate stereo seperation would have required such low Q circuits that
these AM stereo radios would receive way too much noise and interference.

And, as we've seen, it's far better to try and sell magic radios when
everybody else has to put up with the noise and interference.

Frank Dresser

That would be the original Kahn system. I forget the exact name of it. XETRA
used it for many years, and if you had two radios you could tune off channel
high on one and low on the other and get stereo separation. I listened to it
occasionally. It wasn't great, but it was an interesting novelty at the
time.