Cecil Moore wrote in
:

Owen Duffy wrote:
The danger in the "power is refelected at a mismatch" explanation, is
that it follows that power reflected at a mismatched antenna flows
back toward the transmitter and is at least partially absorbed in the
PA as heat. Though that is a popular belief, it is not supported by
fact.

That only applies to mismatched systems. For systems
Z0-matched by an antenna tuner, the situation becomes
trivial to understand. The reflected energy is re-
reflected by the Z0-match provided by the properly
tuned antenna tuner. It's all explained in my energy
analysis article at: http://www.w5dxp.com/energy.htm

Cecil, it seems that between the two of you, you are constructing a
picture that (in a lossless line for simplicity) if the Bird 43 reads
100W forward and 50 watts reflected, the power radiated (ignoring
antenna ohmic losses) is 100W, but 50W is reflected toward the
transmitter... but that's allright because the 50W will be reflected by
a Zo matched PA, and energy is conserved on the line.

The reality is that the Bird responds to Vf and Vr (depending on the
orientation of the slug), and in the special case where the sampler is
calibrated to respond to |Vf| and |Vr| for a purely real ratio of V/I
(Zn=Rn+j0 which is 50+j0 in the case of the '43), on the line at the
point of the sampler, then the average power passing that point is a
single number, it is |Vf|^2/Rn-|Vr|^2/Rn. The foward and reflected power
readings are not meaningful in themselves, but you can deconstruct rho,
and (knowing Zn) |Vf| and |Vr| from them.

Owen