> For a tube amp, sure. And for a solid state amp with a
tuner on the output.
> But not for a broadband SS amp, in general. While they're
not 50 ohm
> resistive, they're also probably not too far away, so the
mismatch at the TX
> output isn't going to be all that huge. If there's not a
big mismatch, most
> of the reflected power winds up "inside" the TX, and gets
dissipated (or fed
> back into the power supply, if you've got an amplifier
that can do that).
Not so Jim.
As Ian and others have tried to point out the end result is
just as if the load impedance was changed by whatever amount
the feedline presents. The efficiency of the PA might
increase, decrease, or stay the same. The PA supply voltage
never increases from "returned power" (if that is what you
were saying). It isn't reflected power burning up or "going
somewhere" in the transmitter, it's the simple fact the PA
is no longer seeing the same load impedance that changes PA
operating parameters.
That "reflected power burns up my PA" is the worse abuse of
a model to ever hit amateur radio.
73 Tom
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