Analyzing Stub Matching with Reflection Coefficients
 

On Apr 27, 7:28 am, Cecil Moore wrote:
Keith Dysart wrote:
Okay, so you can't find anything to point at that is wrong
with the model.

What is wrong with the model is that it doesn't work
in reality.

Hmmm. Having a complete inability to articulate any issues
with the model, you are, none-the-less, convinced that it does
not work in 'reality'. Hmmm.

Of course I claimed no such thing; you do need to read
more carefully. And you have conveniently neglected the
other example which was presented right beside for
which 4 times the "reflected power" was dissipated by
the source. These two completely different results
call into question the nature of "reflected power".

No, they call into question the validity of the model.
The reflected energy is there and can be dissipated
by a circulator load.

The fact that zero energy is dissipated in a source
is prima facie evidence of destructive interference
and a "redistribution of energy in a direction that
allows constructive interference".

But then what is the fact that 4 times the energy is
dissipated in the source prime facie evidence of?

Good explanations explain all the observations, not
just the supporting ones.

....Keith

Analyzing Stub Matching with Reflection Coefficients
 

Keith Dysart wrote:
Hmmm. Having a complete inability to articulate any issues
with the model, you are, none-the-less, convinced that it does
not work in 'reality'. Hmmm.

I have been articulating issues with the model for weeks
now and I am just about articulated out. We are repeating
the same things over and over and unless you take time
out to comprehend interference, there's no reason to
continue.

The fact that zero energy is dissipated in a source
is prima facie evidence of destructive interference
and a "redistribution of energy in a direction that
allows constructive interference".

But then what is the fact that 4 times the energy is
dissipated in the source prime facie evidence of?

Of *total constructive interference* in the source, of
course. I already answered that question days ago. It
is futile to try to communicate with someone who refuses
to listen. Here are the power intensity equations
governing the power dissipated in the two sources in
the previous two examples.

Thevenin equivalent if P1 = P2:
Pdis = P1 + P2 - 2*SQRT(P1*P2) = 0
*Total Destructive Interference* as defined by Hecht in
"Optics", 4th edition, page 388.

Norton equivalent if P1 = P2:
Pdis = P1 + P2 + 2*SQRT(P1*P2) = 4*P1
*Total Constructive Interference* as defined by Hecht in
"Optics", 4th edition, page 388.

Until you learn to recognize interference when it is staring
you in the face, you are going to continue to make the same
mistakes over and over. Forward and reflected energy is alive
and well and obeys the conservation of energy principle. That
you cannot figure out where the photonic energy goes during
a wave interference event is not my problem. Hints about
destructive interference:

www.mellesgriot.com/products/optics/oc_2_1.htm

"Clearly, if the wavelength of the incident light and the thickness
of the film are such that a phase difference exists between reflections
of p, then reflected wavefronts interfere destructively, and overall
reflected intensity is a minimum. If the two reflections are of equal
amplitude, then this amplitude (and hence intensity) minimum will be
zero."

Note that "intensity" is *power density* in watts/unit-area.

"In the absence of absorption or scatter, the principle of conservation
of energy indicates all 'lost' reflected intensity will appear as
enhanced intensity in the transmitted beam. The sum of the reflected and
transmitted beam intensities is always equal to the incident intensity.
This important fact has been confirmed experimentally."

http://micro.magnet.fsu.edu/primer/j...ons/index.html

"... when two waves of equal amplitude and wavelength that are 180-
degrees out of phase with each other meet, they are not actually
annihilated. All of the photon energy present in these waves must
somehow be recovered or *redistributed in a new direction*, according to
the *law of energy conservation* ... Instead, upon meeting, the photons
are *redistributed to regions that permit constructive interference*, so
the effect should be considered as a *redistribution* of light waves and
photon energy rather than the spontaneous construction or destruction
of light."

emphasis mine
--
73, Cecil http://www.w5dxp.com

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:
Keith Dysart wrote:
Certainly the model I described is linear. Is there some
other fault in the model that makes it sufficiently incorrect
to be unusable?

Yes, it doesn't model a class-C amplifier.


Cecil,

I heard a rumor that the FCC does not like people to inject class-C type
pulses directly into an antenna from the output of an amateur transmitter.

Perhaps that rumor is just an urban legend, however, and non-linear
outputs are welcome.


8-)

73,
Gene
W4SZ

Analyzing Stub Matching with Reflection Coefficients
 

Gene Fuller wrote:
I heard a rumor that the FCC does not like people to inject class-C type
pulses directly into an antenna from the output of an amateur transmitter.

Perhaps that rumor is just an urban legend, however, and non-linear
outputs are welcome.

The subject is modeling a class-C source, Gene,
not filtering a class-C source. We all know how
to filter a class-C source. Do you have a model
for a class-C source?
--
73, Cecil http://www.w5dxp.com

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:
Gene Fuller wrote:
I heard a rumor that the FCC does not like people to inject class-C
type pulses directly into an antenna from the output of an amateur
transmitter.

Perhaps that rumor is just an urban legend, however, and non-linear
outputs are welcome.

The subject is modeling a class-C source, Gene,
not filtering a class-C source. We all know how
to filter a class-C source. Do you have a model
for a class-C source?


Cecil,

The original topic was the *output* of an amateur transceiver, e.g., as
seen by a transmission line.

Sorry I did not catch the thread redefinition toward the inner workings
of such a device. That move could open up infinite opportunity for more
arguments.

8-)

73,
Gene
W4SZ

Analyzing Stub Matching with Reflection Coefficients
 

Gene Fuller wrote:
Sorry I did not catch the thread redefinition toward the inner workings
of such a device.

Apology accepted. The crux of what we have been discussing
for days, if not weeks, is what does a model of the active,
dynamic volcano of energy, i.e. the source, look like?
--
73, Cecil http://www.w5dxp.com

Rotational speed
 

Cecil Moore wrote:

Cecil Moore wrote:

Jim Kelley wrote:

Rotational speed has nothing to do with direction of travel.


I assumed that the "same rotational speed" implies
the same direction.

The reason I assumed that is this assertion by W7EL.
"This is the total current. It has magnitude and phase
like any other phasor, and the same rotational speed
as its components."

The total current, as graphed by Kraus and displayed
by EZNEC *DOES NOT* have the same rotational speed as
its components. It is obvious that Roy meant the
same direction when he said "same rotational speed".

I'm sure you're in a better position to know that than Roy is.

ac6xg

Rotational speed
 

Jim Kelley wrote:

Cecil Moore wrote:
Cecil Moore wrote:

Jim Kelley wrote:

Rotational speed has nothing to do with direction of travel.

I assumed that the "same rotational speed" implies
the same direction.

The reason I assumed that is this assertion by W7EL.
"This is the total current. It has magnitude and phase
like any other phasor, and the same rotational speed
as its components."

The total current, as graphed by Kraus and displayed
by EZNEC *DOES NOT* have the same rotational speed as
its components. It is obvious that Roy meant the
same direction when he said "same rotational speed".

I'm sure you're in a better position to know that than Roy is.

It's a matter of logic, Jim. We know that the forward
current and reflected current phasors are rotating in
opposite directions. Kraus and EZNEC say that the
phase angle of the current on a 1/2WL dipole changes
by only 2 degrees, end to end. Therefore, contrary to
what Roy asserted, the total current does NOT have the
same rotational speed as its components.

That was Roy's mistake in using total current to try
to measure phase shift through a coil. One cannot
use total current phase on a standing wave antenna
to determine any valid measurement concerning phase
shift through a coil. But since the phase information
is preserved in the total current amplitude, it can
be used to estimate phase shift through the coil.

Roy said, "What I measured was a 3.1% reduction in
magnitude from input to output, with no discernible
phase shift."

From this, for a base-loaded coil we can estimate the
phase shift through the coil to be

arccos(.969) = 14.3 degrees

With no discernible phase shift we can estimate that
there was no decrease in current from end to end for
either the forward current or reflected current.
--
73, Cecil http://www.w5dxp.com

Rotational speed
 

Cecil Moore wrote:


We know that the forward
current and reflected current phasors are rotating in
opposite directions. Kraus and EZNEC say that the
phase angle of the current on a 1/2WL dipole changes
by only 2 degrees, end to end. Therefore, contrary to
what Roy asserted, the total current does NOT have the
same rotational speed as its components.

Due to the shape of the North American elk's esophagus, even if it
could speak, it could not pronounce the word lasagna.

Cliff Claven

Rotational speed
 

Jim Kelley wrote:

Cecil Moore wrote:
We know that the forward
current and reflected current phasors are rotating in
opposite directions. Kraus and EZNEC say that the
phase angle of the current on a 1/2WL dipole changes
by only 2 degrees, end to end. Therefore, contrary to
what Roy asserted, the total current does NOT have the
same rotational speed as its components.

Due to the shape of the North American elk's esophagus, even if it could
speak, it could not pronounce the word lasagna.

The technical content of your posting is noted. Roy can
easily verify that EZNEC disagrees with his assertion
that "the total current has the same rotational speed
as its components". The total current has hardly any
rotational speed at all, i.e. 2 degrees of rotation
end-to-end in 180 degrees of a 1/2WL dipole.
--
73, Cecil http://www.w5dxp.com