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Old June 14th 11, 08:53 PM posted to rec.radio.amateur.antenna
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Default Reflection coefficient for total re-reflection

On Tue, 14 Jun 2011 12:25:33 -0700 (PDT), walt wrote:

Thank you for your insightful response, Richard. However, I must plod
on, and introduce the results of my own measurements, the data of
which appear in Chapter 19, Sec 19.14 of Reflections 3. Using a
Kenwood TS-830S I measured the parameters required to prove the output
source resistance of the tank circuit of its RF power amp is non-
dissipative. The measurements also prove that the reflected power
incident on its output is totally re-reflected. From reading an
earlier post of yours, Richard, I know you have read this portion of
Chapter 19, and you agreed with it. My measured data conflicts with
Best's Eq 8, so there's got to be a valid answer to this dilemma, but
where?

Walt


Hi Walt,

Yes, I am very familiar with your bench work. I am very annoyed by
those who trivialize it. I am further annoyed by those who patronize
you to then shift the parameters to explain something else -
completely abandoning you.

However, I also acknowledge that I can hurt your feelings about where
I stand on these matters. Yes, to a limited degree, I do agree with
much of your assessment, but I do not follow it into the arena of
where you express it as being "non-dissipative."

However, my denying this proposition does NOT mean I dispute your
other proposition of complete reflection. This cross connection of
several topics is where things get overly complex and gives the entire
discussion the appearance of a house of cards.

I cannot tell what your agenda is, but the material you quote as
source, and for which I have provided links to in this thread - all
seem a subtext to non-dissipative sources. Attention directed towards
this pursuit of matching points rendered in stubs seems like tea leaf
reading to resolve a larger issue.

As a student, tech, and engineer employing a LOT of precision
waveguide technology, I am quite comfortable with the components and
topologies you describe. Arguments for wave interferences being
rendered into useful circuit constructs (that is, constructed on the
basis of wave interference) has been with us easily since the early
40s. One component, the ATR tube, is one I have handled and replaced
to insure the proper operation of RF paths being steered in
waveguides. One proviso, however = for any of these
"virtualizations" to work, they require a physical (and dissipative)
element as the initiator. Waves do not interfere without the presence
of a physical element (often some form of detector, or minimally a
load).

73's
Richard Clark, KB7QHC
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Old June 14th 11, 10:18 PM posted to rec.radio.amateur.antenna
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Default Reflection coefficient for total re-reflection

On Jun 14, 3:53*pm, Richard Clark wrote:
On Tue, 14 Jun 2011 12:25:33 -0700 (PDT), walt wrote:
Thank you for your insightful response, Richard. However, I must plod
on, and introduce the results of my own measurements, the data of
which appear in Chapter 19, Sec 19.14 of Reflections 3. Using a
Kenwood TS-830S I measured the parameters required to prove the output
source resistance of the tank circuit of its RF power amp is non-
dissipative. The measurements also prove that the reflected power
incident on its output is totally re-reflected. From reading an
earlier post of yours, Richard, I know you have read this portion of
Chapter 19, and you agreed with it. My measured data conflicts with
Best's Eq 8, so there's got to be a valid answer to this dilemma, but
where?


Walt


Hi Walt,

Yes, I am very familiar with your bench work. *I am very annoyed by
those who trivialize it. *I am further annoyed by those who patronize
you to then shift the parameters to explain something else -
completely abandoning you.

However, I also acknowledge that I can hurt your feelings about where
I stand on these matters. *Yes, to a limited degree, I do agree with
much of your assessment, but I do not follow it into the arena of
where you express it as being "non-dissipative." *

However, my denying this proposition does NOT mean I dispute your
other proposition of complete reflection. *This cross connection of
several topics is where things get overly complex and gives the entire
discussion the appearance of a house of cards.

I cannot tell what your agenda is, but the material you quote as
source, and for which I have provided links to in this thread - all
seem a subtext to non-dissipative sources. *Attention directed towards
this pursuit of matching points rendered in stubs seems like tea leaf
reading to resolve a larger issue.

As a student, tech, and engineer employing a LOT of precision
waveguide technology, I am quite comfortable with the components and
topologies you describe. *Arguments for wave interferences being
rendered into useful circuit constructs (that is, constructed on the
basis of wave interference) has been with us easily since the early
40s. *One component, the ATR tube, is one I have handled and replaced
to insure the proper operation of RF paths being steered in
waveguides. *One proviso, however = for any of these
"virtualizations" to work, they require a physical (and dissipative)
element as the initiator. *Waves do not interfere without the presence
of a physical element (often some form of detector, or minimally a
load).

73's
Richard Clark, KB7QHC


Thanks again Richard, for your insightful response. And goodness no,
Richard, you won't hurt my feelings. I like being correct, but if I'm
not I surely want to be told about it. This situation is no different.

However, if you're not following me on the 'non-dissipative' path, I'd
like you to review the last portion of the TS-830S experiment, and
follow the numbers. If you don't have that material in front of you,
you can find it again on my web page at www.w2du.com. Click on
'Preview Chapters from Reflections 3', and then click on Chapter 19A,
which is a part of Chapter 19 in the 3rd edition.

Observe that when the load impedance is changed from 50+j0 to the
complex impedance 17.98 + j8.77 ohms, the plate current rose
expectedly from 260ma to 290ma. This change occurred because the amp
is now mismatched, and the pi-network is also detuned from resonance.
The unwashed would conclude that the reflected power caused the
increase in plate current. However, one will also observe that after
the pi-network has been retuned and adjusted to again deliver all the
available power into the otherwise 'mismatched' load (which is now
matched to the source), the plate current went back to it's original
value, 260ma. In addition, the amp returned to deliver 100w into the
complex impedance at the line input, with the 30.6w of reflected power
in the line, and adding to the 100w of source power, making 130.6w
incident on the mismatched load, absorbing 100w and reflecting 30.6w.

IMHO, these data prove beyond doubt that the pi-network not only
didn't absorb any of the reflected power, but totally re-reflected it.
In my book this says the pi-network reflection coefficient rho = 1.0.
How can anyone disagree with this?

Walt
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Old June 15th 11, 12:23 AM posted to rec.radio.amateur.antenna
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First recorded activity by RadioBanter: Jul 2006
Posts: 2,951
Default Reflection coefficient for total re-reflection

On Tue, 14 Jun 2011 14:18:53 -0700 (PDT), walt wrote:

Thanks again Richard, for your insightful response. And goodness no,
Richard, you won't hurt my feelings. I like being correct, but if I'm
not I surely want to be told about it. This situation is no different.

However, if you're not following me on the 'non-dissipative' path, I'd
like you to review the last portion of the TS-830S experiment, and
follow the numbers. If you don't have that material in front of you,
you can find it again on my web page at www.w2du.com. Click on
'Preview Chapters from Reflections 3', and then click on Chapter 19A,
which is a part of Chapter 19 in the 3rd edition.

Observe that when the load impedance is changed from 50+j0 to the
complex impedance 17.98 + j8.77 ohms, the plate current rose
expectedly from 260ma to 290ma. This change occurred because the amp
is now mismatched, and the pi-network is also detuned from resonance.
The unwashed would conclude that the reflected power caused the
increase in plate current. However, one will also observe that after
the pi-network has been retuned and adjusted to again deliver all the
available power into the otherwise 'mismatched' load (which is now
matched to the source), the plate current went back to it's original
value, 260ma. In addition, the amp returned to deliver 100w into the
complex impedance at the line input, with the 30.6w of reflected power
in the line, and adding to the 100w of source power, making 130.6w
incident on the mismatched load, absorbing 100w and reflecting 30.6w.


Hi Walt,

There is absolutely NOTHING that I can dispute in your numbers or
method. However, as to "dissipation" this says nothing.

As for what it says about the reflection coefficient, I would agree
with you. However, the math and the math experts you speak of - they
are not answering the model we are examining above. You distracted
them with stubs and reflecting waves.

If you cast this agreement in the reflection coefficient back into
effects purported to exist in the matching with stubs model, we may
yet argue.

IMHO, these data prove beyond doubt that the pi-network not only
didn't absorb any of the reflected power, but totally re-reflected it.
In my book this says the pi-network reflection coefficient rho = 1.0.
How can anyone disagree with this?


*** Nothing further useful about the topic is to be found below ***

There is a curious side bar to this found at:
http://www.w5big.com/purchase4170c.htm
Observe the second data screen that purports to examine a mismatch
through a length of both RG58 and RG59 terminated with 100 Ohms.

Of particular note is the distinct transition from the Zc of 50 Ohms
to the Zc of 75 Ohms and the similarly distinct transition from the Zc
of 75 Ohms to the termination R of 100 Ohms. Note that the
transitions both span a distance of 2 feet. 2 feet is not
insubstantial compared to connection technology that spans, probably,
no more than one tenth that distance. Whence the extra 11 inches on
both sides of the connection plane of either connection?

In the physics I've been studying for the past 10 years, near fields,
this would not be unusual. In fact it would be expected. There is a
transition zone (in waveguide design, there would be a taper or a
sweep section to anticipate this and they would be physically large in
terms of wavelength) not a transition cliff.

Similarly, at the connector to your TS-830S, there is a zone that
surrounds it that only approximates the 50 Ohm which occurs (in the
terms of this link's demonstration) some distance away, deep inside
your TS-830S.

To me, dissipation inhabits this zone (certainly large enough for the
tube and tank to occupy) and embraces the match with a complex
addition of phases that could result in loss or even gain. This is
also to say that I do not subscribe to dissipation being all about
loss - especially when the hand of man is on the tuning knob instead
of letting the chips fall where they may.

73's
Richard Clark, KB7QHC
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