One of the issues discussed in this thread that Owen originated concerned whether or not reflected power
enters the power amp and dissipates as heat in the plates of the amp. Some of the posters apparently are
unable to appreciate that the reflected power does not cause heating of the amp, unless the reflected power
detunes the amp and the amp is left detuned from resonance, which of course is not the correct manner of
operating the amp.

In the last post of the original thread I presented the details of an experiment I performed (one of many
using the same procedure) on a Kenwood TS-830S transceiver that proves how and why reflected power in no way
causes heating of the amp when the amp is properly adjusted in the presence of the reflected power.

Usually, such a presentation as in the last post in that thread evokes a great deal of response, as for
example, Art Unwin's. So I'm somewhat surprised, and a little disappointed that my post has resulted in total
silence. Have my efforts in helping to solve the problem gone for naught?

Walt, W2DU

Walter Maxwell wrote:
Some of the posters apparently are
unable to appreciate that the reflected power does not cause heating of the amp, unless the reflected power
detunes the amp and the amp is left detuned from resonance, which of course is not the correct manner of
operating the amp.

Some would say that if "reflected power does not cause heating
of the amp", that proves that there is no power (or energy) in
the reflected waves. Those people obviously don't understand
the role of destructive and constructive interference during
the EM wave superposition process.
--
73, Cecil http://www.w5dxp.com

On Tue, 20 Mar 2007 10:55:12 -0500, Cecil Moore wrote:

Walter Maxwell wrote:
Some of the posters apparently are
unable to appreciate that the reflected power does not cause heating of the amp, unless the reflected power
detunes the amp and the amp is left detuned from resonance, which of course is not the correct manner of
operating the amp.

Some would say that if "reflected power does not cause heating
of the amp", that proves that there is no power (or energy) in
the reflected waves. Those people obviously don't understand
the role of destructive and constructive interference during
the EM wave superposition process.

In addition, Cecil, the experiment also proves that the reflected power doesn't heat the plate, because the
output source resistance is non-dissipative.

Walt

Cecil Moore wrote:

Some would say that if "reflected power does not cause heating
of the amp", that proves that there is no power (or energy) in
the reflected waves. Those people obviously don't understand
the role of destructive and constructive interference during
the EM wave superposition process.

Cecil,

What reflected waves?

An equally valid description in steady state, after all the transients
have died out, includes a standing wave containing the stored energy in
the line plus a forward traveling wave carrying the energy that does
make it through the load end of the line.

No need to account for any mythical power in the reflected waves.

This description matches your quotes from Hecht and from Ramo and
Whinnery that I attached a few days ago.

73,
Gene
W4SZ

Gene Fuller wrote:
No need to account for any mythical power in the reflected waves.

How can you possibly deny the existence of the reverse
traveling wave and then be incapable of providing an
example of a standing wave existing without a reverse
traveling wave? Sounds like smoke, mirrors, and arm-
waving to me.
--
73, Cecil http://www.w5dxp.com

Walter Maxwell wrote:
In addition, Cecil, the experiment also proves that the reflected power doesn't heat the plate, because the
output source resistance is non-dissipative.

I understand what happens to the direction and
momentum in the reflected wave when it encounters
an impedance discontinuity at some distance from
the source, e.g. a Z0-match.

What happens to the direction and momentum in the
reflected wave when it encounters a non-dissipative
resistance at the source?
--
73, Cecil http://www.w5dxp.com

Gene, W4SZ wrote:
"No need to account for any mythical power in the reflected waves."

Cecil has an IEEE dictionary which defines power in terms of the voltage
and in-phase current passing a point.

Terman says on page 96 of his 1955 opus:
"The reflected wave is identical with the incident wave except that it
is traveling toward the generator."

Bird says of its Model 43 RF Directional "Thruline" Wattmeter:
"The forward wave travels (and its power flows) from the source to the
load. It has RF Voltage Ef and current If in phase, with Ef/If=Zo.

The reflected wave originates by reflection at the load, travels (and
its power flows) from the load back to the source, and also has an RF
voltage Er and current Ir in phase, with Er/Ir=Zo."

Best regards, Richard Harrison, KB5WZI

Richard Harrison wrote:
Terman says on page 96 of his 1955 opus:
"The reflected wave is identical with the incident wave except that it
is traveling toward the generator."

Gene needs to tell us how the TV modulation that
causes ghosting makes its predictable round trips
to the source and back without the aid of the
reverse traveling wave.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote in news:7iYLh.73$Kd3.72
@newssvr27.news.prodigy.net:

Gene needs to tell us how the TV modulation that
causes ghosting makes its predictable round trips
to the source and back without the aid of the
reverse traveling wave.

Talk about echoes!

Cecil, at the time of writing, you have made 4 of the 7 responses to
Walt's posts, and there is nothing in what you have said that you haven't
said recently.

The language from various posters like:

"Some of the posters apparently are unable..."

"Some would say..."

"people obviously don't understand..."

"How can you possibly deny..."

doesn't seem to me the language of convicing arguments, much less proof,
from either side. They seem more a sign of the posters frustration, but
not otherwise convincing.

My guess is that this discussion will not converge on a convincing
outcome.

If the past is any indicator, just when agreement of two or three people
looks likely, someone will inject some noise like lets start dealing with
time domain and transient issues to prove that steady state analysis is
invalid in the practical sense, or this needs a photon explanation with
reference to a text no one is likely to have. It as though those posters
intended to wreck logical development and conclusion. Ah, but that is
USENET!

The basis of the assertion that a PA is naturally or magically conjugate
matched as a necessary consequence of adjustment or design for maximum
power output is based on an leveraging the Maximum Power Transfer Theorem
which depends on a linear source. I don't recall seeing experimental
results to convincingly demonstrate that the PA is a linear source,
though I have seen those that suggest otherwise. If the source cannot be
proven to be sufficiently close to a linear source, then the basis for
arguing the implicit conjugate match dissolves.

No one has yet come up with a quantitative proof that in the general case
PAs of all kinds have an equivalent source impedance the conjugate of
their load, nor convincing experiments that would place bounds on the
reflection coefficient looking into the PA for practical transmitters.

No one has demonstrated that using equivalent impedances etc is not a
valid analysis of the steady state behaviour.

Owen

On Tue, 20 Mar 2007 22:06:35 GMT, Owen Duffy wrote:

I don't recall seeing experimental
results to convincingly demonstrate that the PA is a linear source,
though I have seen those that suggest otherwise. If the source cannot be
proven to be sufficiently close to a linear source, then the basis for
arguing the implicit conjugate match dissolves.

Owen, despite our previous discussion, I have explained many times that even though the PA source upstream of
the tank circuit is non-linear (and no one's saying it isn't), the energy storage in the tank makes the output
of the tank a linear source, no matter what the shape of the current wave form may be at the input. The output
of the tank is proved linear because the voltage/current ratio at the output is non-varying and the shape of
the voltage and current wave forms are essentially sine waves. Consequently, the output circuit can be
represented by a Thevenin source that supports both a conjugate match and the maximum power transfer theorem.

Are you now denying that the output of a PA with the routine Q of 10 to 12 is not substantially a sine wave?
If you agree that it is a sine wave, then why are you arguing that there is no basis for a conjugate match?

However, none of the responses above respond to the issue of why the reflected power does not cause heating of
the amp, which is what my treatise was all about.

Walt, W2DU