"William E. Sabin" wrote Reg Edwards wrote:

A so-called directional wattmeter or SWR meter merely responds to the
magnitude of a reflection coefficient usually, but not necessarily,
relative
to 50 + j0 ohms. Half of the information, the angle, is discarded
without
being aware of its existence.


Not exactly correct.

The phase information is not displayed explicitly
on a scaler instrument like the Bird meter, but
phase is definitely involved in the principles of
operation of the directional coupler.

Very seldom, if ever, do we care a feather or a
fig what the exact phase value is, but the
directional coupler is not balanced unless the
phase is zero.

All automatic antenna tuners utilize this fact.

Bill W0IYH

===================================

Bill, why the unnecessarily complications?

It is possible to imagine the so-called SWR meter is telling you the
imaginary value of the SWR on a non-existent transmission line. But it's
hardly of educational value when novices, even experienced engineers, are
trying to understand what the reading really means. It's as confusing and
as untruthful as Blair.

Why don't we accept the simple fact that the meter tells us only whether the
transmitter is loaded with a resistance of a particular value or not. Which
is no more nor less than what the instrument on the front panel of your
transceiver is provided for.

Then we can forget all about SWR, fwd and reflected power, until needed on
real ines. Change the name of the meter to TLI.
---
Reg, G4FGQ