Owen Duffy wrote:
I can't see why an attempt to impedance match the source was necessary,
the reflection coefficient is determined solely by the load and line
characteristics.

This may (or may not) be a source of misunderstandings on this
newsgroup. If the source is not matched to the characteristic
impedance of the environment, then reflections result, even if
they are "same-cycle" reflections. That leads to such concepts
as unchanging phase all around the circuit in violation of the
rules for distributed networks.

Ask yourself this question: One inch away from a mismatched load
at HF frequencies, do reflections exist? If your answer is "no",
it is time to question your concepts. If your question is "yes",
then the same thing happens when the load is one inch away from
the source. Think about that.

If you were confident that reflection was insignificant, then this test
design might properly reveal the one way delay of the transmission line
section.

The goal in this type of measurement is to reduce the reflections
to a manageable level. If one recognizes what one is observing, one
can "see" the forward waves when the standing wave is half of
the total waveform. Ideally, the reflections would be eliminated,
but that is not an absolutely necessity.

I don't suspect that the outcome of a properly designed and executed
experiment is going to surprise anyone.

I can guarantee you it will be a total surprise to most of the
omniscient "gurus" on this newsgroup who will deny its validity.
If you side with the technical results of such an experiment, you
will be labeled a mentally disabled kook or worse.
--
73, Cecil http://www.w5dxp.com