David G. Nagel wrote:
What I was taught long ago was that the phenomenon that we call
reflected energy is radiated on the return. That portion of energy that
is not radiated is re-reflected and is radiated. This continues until
the level of energy no longer supports radiation. Resistance also
dissipates a portion of the transmitted energy. That resistance includes
the resistor under discussion above and that resistance found in the
coax conductors.

Of course my Elmer could have been wrong.

Your Elmer was parroting the party line which is:
Any reflected energy dissipated in the source was
never sourced in the first place. Therefore,
at the source (by convention and by definition):

Sourced power = forward power - reflected power

If that is true, it follows that all reflected power
must necessarily be re-reflected back toward the load
(even if, in the process, it violates the laws of physics
governing the reflection model). Since contradictions
don't exist in reality, there must be another explanation.

An antenna tuner which achieves a Z0-match allows no
reflected energy to be incident upon the source so, for
that most common configuration, all is well and your
Elmer was right about those Z0-matched systems.

However, when reflected energy is allowed to reach
the source, it is naive to think that none of that
reflected energy is ever dissipated in the source
resistance when the source resistance is dissipative
as it is in the example under discussion here.

Both of the following assertions are false:
1. Reflected energy is never dissipated in the source.
2. Reflected energy is always dissipated in the source.
Most assertions containing the words "always" and "never"
are false.

There will be three more parts on this topic published
on my web page. The top page will be on the subject
of interference which will explain how reflected energy
can be redistributed back toward the load after not
being re-reflected.
--
73, Cecil http://www.w5dxp.com