Reg Edwards wrote:
"Cecil Moore" wrote
If forward and reverse waves do not exist separately,
how is it possible for a circulator to separate them?

You forgot to allow TIME into the argument.
The two waves do NOT, and cannot, exist seperately in time.

I'm not sure what your point is. If a laser beam is
aimed at a mirror, do the forward wave and reflected
wave exist separately in time? If we send a forward
wave down a one-second lossless feedline for one second
and turn it off, nothing happens for one second. Then
we receive a reflected wave for one second. Do those
waves not exist separately in time?

The circulator merely divides the STEADY STATE, instantaneous, at the
same time, power in the wave into two parts according to what the
operator, or by design, has set it to do.

The point is that one of those parts has made a round
trip to the load and back as can be proved by observing
ghosting in TV signals.

When the generator is switched off both parts disappear
simultaneously.

Not entirely true. The reflected wave would continue to
exist until the energy in the transmission line is
dissipated.
--
73, Cecil, http://www.qsl.net/w5dxp