Don ... you are correct!
73, Lee ZL2AL (Old AMer of the 50s)


Getting back to basics: A 120W (input) power, class C stage, will
require
60W of audio (using a high-level, e.g. plate, modulator) for 100%
modulation. If we assume 85% efficiency, then the output will consist
of
a
Carrier of 102W and two sidebands of 25.5W each.

In my opinion, any other explanation is useless. Do remember that the
carrier amplitude does NOT vary with modulation.

Don

Wohoooo here, maybe, since I caught this thread in mid stream, I am out
of place, but Don, your last sentence, "Do remember that the carrier
amplitude does NOT vary with modulation." doesn't sound like high level
amplitude modulation.

When I was young(er), amplitude modulation meant exactly that: carrier
amplitude varying with modulation. In fact, when working out the bugs of
home designed and built AM transmitters, one favorite test was with an
oscilloscope, measuring the amplitude of the carrier, making sure that the
carrier amplitude did actually approach zero and rise to twice the
unmodulated carrier level. (voltage, not power, of course)

Now, for sure, the carrier average POWER didn't vary (much), but the
audio power was added. Now, PEP, peak envelope power, is a whole different
thing for us old timers, and maybe that's what is being discussed here. In
that case, please excuse Mr. Buttinski!

Old Chief Lynn, W7LTQ