"John Smith I" wrote in message
...
Listen to a "strong--pure am signal" on an fm receiver, turn up the volume
on the fm receiver, something is responsible for that ... repeat
experiment with the reverse ... "imperfect world theory" proof!

What is responsible for that is not that AM somehow also
produces FM, but simply that the type of demodulator used
by the FM receiver in question will also demodulate AM to
a usable degree. Ditto the reverse (look up "slope detection"
for an example of how a very common AM demodulator
can also demodulate FM).

Bob M.