On May 26, 11:50*am, Richard Clark wrote:
On Wed, 26 May 2010 04:50:30 -0700 (PDT), Keith Dysart

wrote:
a conjugate match does result in a situation where altering
the load will reduce the power transfer

...

We are still left with the puzzle of why the observations documented
in Reflections report a reduction in power transfer when the load is
changed in either direction.

Hi Keith,

Stripping away everything that you offer as objections to what is not
in Walt's premise (I cannot vouch for his attempts to explain the
universality of it), your statements come into conflict.

If you offer you find a puzzle about measurements, then that is simply
researched at the bench instead of in expansive wanderings in myriad
qualifications. *Do you have documented measurements under initial
conditions identical to Walt's that run counter to Walt's quantitative
results?

I suspect not, or we would be talking about competing bench results
instead. *This would be a more productive and genuine debate seeking
explanation for what you describe as the "puzzle." *

Barring quantitative evidence, anything that continues this rag-chew
is a simple example of "modeling is doomed to succeed."

73's
Richard Clark, KB7QHC

Hi Keith,

Sorry, OM, but you still misunderstand various aspects of RF power amp
operation.

First, the power supply is not the limiting factor concerning plate
current. The grid drive is what determines the plate current, and thus
the output power.

Second, the tank circuit is an energy storage device that isolates the
non-linear input from the linear output. That the output is linear is
because the voltage and current are in phase at the output of the tank
circuit. The effect of the energy storage of the tank results in the
tank becoming the source of the energy appearing at the output.

Third, the action of plate resistance Rp occurs only in the formation
of RL, and has no further effect on any action downstream of the input
of the tank circuit. Thus, it has no bearing on the development of the
conjugate match that occurs at the junction of the tank output and the
input of the transmission line.

Fourth, as I said earlier, the the action of the bench power supply
that you presented in no way models the action of the RF power
amplifier. Furthermore, you are incorrect when you say that when
varying the load in either direction causing the power deliver to
decrease there is no conjugate match. In saying what you did violates
the theorem of Maximum Transfer of Power.

Fifth, as I stated earlier, when the reactance appearing at the input
of the load (the transmission line with reflections) is canceled by
the opposite reactance introduced by the pi-network tuning capacitor,
the output impedance of the source (the tank circuit) is the conjugate
of the line-input impedance. If you cannot accept this as fact you
have a problem.

Sixth, your understanding of the effect of the reflected wave on the
source wave is flawed. The non-linearity of the plate current when the
conduction time is less than 360° has no relation to the action
downstream of the input to the tank circuit, because from that point
on the voltage current relationship is linear. If you cannot accept
this as fact you have still another problem.

Seventh, your belief that because there is a conjugate match at the
output of the tank there must be a conjugate match at the input of the
tank is also not true. The effect of the energy storage in the tank
isolates the non-linearity af the input from the linear operation at
the output, permitting a conjugate match at the output, while not
allowing it to occur at the input.

These seven comments are born out (proven) by the results of many
measurements I made using laboratory grade instruments, HP and General
Radio. If you check my record as a professional electrical engineer
regarding the measurements I've made that led to successful hardware
flying on various Earth-orbiting platforms, you must accept the
validity of the measurements I made on RF power amplifiers that prove
my position.

As I said earlier, no one but you has considered my position on this
subject incorrect. Therefore, if you cannot agree with the comments I
made above, but still consider my statements in Reflections flawed,
then there is no point in my making any further comments. I hope
someday you'll finally understand what's really happening within the
RF amplifier.

Walt Maxwell, W2DU