On Jun 13, 4:33*pm, walt wrote:
The point I'm emphasizing
is that because the output resistance of these amps is non-
dissipative, no reflected power from a mismatched load enters the amp,
but is totally re-reflected in the forward direction.

Walt, wouldn't that non-dissipative output resistance also reflect
reverse power on other close frequencies, such as those coupled from a
co-located transmission system within the bandwidth of the tx output
network?

If so, such external signals would never enter the transmitter, and
could not cause r-f intermodulation by mixing with the main signal in
the (non-linear) PA plate circuit of that transmitter to produce a 3rd
order product at 2F1 - F2, and other combinations.

But such r-f intermods are a fact of life, as shown in the Mendenhall
paper, and in the existence of elaborate and expensive r-f filtering
hardware needed to enable several stations to operate from one
location while meeting a radiated r-f intermod spec of -80 dBc -- even
from one antenna!

RF