"Ian White, G3SEK"wrote:
Richard Fry wrote:
"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.

Sorry, that statement cannot be correct. It would mean that the
impedance you measure at the near end of a transmission line (terminated
by some arbitrary load at the far end) would depend on the internal
impedance of the device that's doing the measuring - and that is not
true, either in transmission-line theory or in the real world. It is a
function only of the line and the load. etc
____________

How, then, do you explain the "ghost image" that can occur* in analog(ue) TV
transmission systems arising from reflections at/near the antenna end of the
station's transmission line?

*with sufficient round-trip propagation time in the transmission line

RF