Roy Lewallen wrote:
If the driving circuitry consists of a perfect voltage source in series
with a resistance, the source Z will be the resistance;

This is obviously not true and easily illustrated using
a battery.

| |
Gnd--||---\/\/\/\/---+---(I)---||--Gnd
| 50 ohms |
12v 12v

Using a 12v source and current meter (I) to test the
impedance to ground from point '+', what does that
V/I impedance measure? Can you spell infinity?

The same principle holds true for an AC source when
phase is considered. Replace the 12v battery with
a 12vac source and test the impedance at '+' with
a phase-locked 12vac source. The measured V/I will
be infinite just as it is in the DC case.

It would certainly appear that the reflection coefficient
seen by the reflections changes depending upon the phase
of the reflections. In any case, the source Z is obviously
not what the reflections encounter.
--
73, Cecil http://www.w5dxp.com