Cecil Moore wrote:

And given the following example from "Fields & Waves ..." by
Ramo & Whinnery, what do you think changes the direction of
the Pz2- Poynting Vector such that it vectorally adds to the
Pz1+ Poynting Vector resulting in the Pz2+ Poynting Vector?

100W XMTR---50 ohm line---+---291.4 ohm line---1698.5 ohm load
Pz1+ = 100W-- Pz2+ = 200W--
--Pz1- = 0W --Pz2- = 100W

If you can answer that simple question to the satisfaction of
everyone, the discussion will be over.

Any reflections (and Poynting vector reversals) would be caused by the
presence of impedance discontinuities - not by anything else. In the
absence of impedance discontinuities, the transmission line would appear
to be infinitely long and would not produce reflections.

ac6xg