Radium wrote:

...
If a carrier signal varies by anything other than just amplitude, then
it isn't AM. Right?


Let logic be your guide, again. As was pointed out earlier, the voice
freqs which modulate the carrier will cause a variance in freq (a small
fm component.)

In fm, it is not unusual for a small "amplitude modulation" to be
generated, as the varying/spanning of freq(s) is caused by the
modulation, some changes in fm carrier can be generated.

In an imperfect world, nothing is "perfect."

Regards,
JS