"Ian White, G3SEK wrote
The meter measures nothing that involves the source, except
the level of RF that it supplies. It does not respond in any way
whatever to the source impedance.
_____________

Not that I said it did in my part of the thread, but nevertheless the above
statement is not strictly true. In the case where the source Z of the tx PA
does not match its load Z (which is typical), power reflected from the load
mismatch will at least partly be re-reflected from the PA -- which then
contributes to the power sensed by a "wattmeter" in the output path.

RF