Keith Dysart wrote:
The impedance of the Thevenin/Norton equivalent source
is not V/I but rather the slope of the line representing
the relationship of the voltage to the current.

However, after the interference patterns have been
established, the reflected waves do not encounter that
source impedance. That is why the reflection coefficient
seen by the reflected waves is relatively unrelated to
the value of resistance in a Thevenin equivalent circuit.

You need to complete step 3 of the superposition process
to realize exactly what is happening. Reference the
irradiance equation from the field of EM wave optics
to ascertain the interference levels. What do you have
to lose by alleviating your ignorance?

Keith, until you take time to understand destructive and
constructive interference, you will never understand what
is happening inside a source and will be forever confused
by your blinders-on-come-hell-or-high-water method of
thinking. Optical physicists figured out a couple of
centuries ago exactly what you are wrestling with now.
Your present problem was already solved before your
grandfather was born.
--
73, Cecil http://www.w5dxp.com