I see that I am going to have to re-assert your own standard:

On Fri, 11 Jun 2010 20:31:42 GMT, Owen Duffy wrote:

there is a proposition that a transmitter "designed/adjusted
for, and expecting a 50 + j 0 ohm load" can be well represented by a
Thevenin equivalent circuit and naturally has Zeq=50+j0.

On Sat, 12 Jun 2010 00:19:34 GMT, Owen Duffy wrote:

For the data I asked, you supplied:
I have performed many tests on many radios. One documented example is at
http://vk1od.net/blog/?p=1045 .
and offered:
I invite you and others to perform the same test. You will realise that
one, or even 100 supporting tests do not prove the proposition, but one
valid test to the contrary is damaging.

The test of proving the "proposition" invalid is, in part:
Adjusting the load impedance ... on this load with VSWR(50)=1.5
... is proof that the equivalent source impedance of the transmitter is not 50+j0Ohm.

I observed how you violated the adjusted-for part of
"designed/adjusted for, and expecting a 50 + j 0 ohm load."

As no claim has been made by anyone about a source being constant in Z
nor in Power across all loads and all frequencies, your response does
not conform to your own reprise of the "proposition."

*******

What you have performed is a load pull which constructs a curve of
complex source impedances around the point at which the transmitter
was adjusted for a 50 Ohm load. All well and good. However,
Thevenin's theorem says nothing of this. The correct test, to the
letter of the theorem is a test no one performs: the measured open
circuit voltage divided by the measured short circuit current.

*******

If I were to return to another statement from your link offered in my
quote above:
the transmitter is 50+j0Ohm
is in all likelihood incorrect. I am speaking strictly to what is
reported and to the implied accuracy of 50 ±0.5 Ohms. I seriously
doubt that you have the means to achieve the absolute accuracy of 1%.

To many, this is a trivial point - simply because they, too, are
wholly incapable of achieving even ten times this error. That is,
measure an RF power in the HF to within ±10%. So I often get shrugged
off with a dismissal of "so what?"

What is this scrabbling over decimal points that I am making? IF:
the equivalent source impedance of the transmitter is not 50+j0Ohms
then it could easily be satisfied by it being 51+j0Ohms, as you do not
report what the Z was. I am sure some would condemn 51 Ohms with
sneering contempt. Reports of what the Source Z "is not" is not
informative in the least. What the significance 1 Ohm has when the
likelihood of being able make a measurement with much less range of
error is approaching nil and thus does not stand as a very rigorous
proof AGAINST the "proposition."

Similarly, IF:
the equivalent source impedance of the transmitter is 50+j0Ohms
then even this may not qualify if the source impedance MUST be
50+j0Ohms as, again, the likelihood of being able make a measurement
within ±1% range of error is approaching nil and thus does not stand
as a very rigorous proof FOR the "proposition."

********

Last, I see the lack of rigor in reporting that is so evidenced by
Walt's work. I am familiar with EVERY one of his lab instruments
(enumerated elsewhere) as I have calibrated ALL like them in three
different RF Standards laboratories over my career as a Metrologist. I
am wholly informed as to their capabilities and capacities to perform
the tests he reports to the precision and accuracies he documents. I
am also trained in the methods of performing this work and I have read
from Walt's descriptions that he has taken care to observe the proper
methods. All of these considerations are scrupulous to his first two
steps of his description which amply demonstrate:
there is a proposition that a transmitter "designed/adjusted
for, and expecting a 50 + j 0 ohm load" can be well represented by a
Thevenin equivalent circuit and naturally has Zeq=50+j0.

73's
Richard Clark, KB7QHC