On May 25, 10:41*pm, lu6etj wrote:
Is not possible you are using different models to describe an only one
phenomenon?, as looking at the same cat from their muzzle or from his
tail believing each one his cat is the true or real "cat" :)

Dr. Corum tells us what the problem is: "Lumped circuit theory fails
because it's a *theory* whose presuppositions are inadequate. Every EE
in the world was warned of this in their first sophomore circuits
course. ... The engineer must either use Maxwell's equations or
distributed elements to model reality. ... Distributed theory
encompasses lumped circuits and always applies."

In particular, *energy flow* is not addressed at all in the lumped
circuit model. Some RF gurus are so confused that they imply that
there is no Poynting vector power density in reflected waves. Their
basic error (for the past 8 years) is that they believe there is no
mechanism outside of the reflection model that can redistribute the
reflected energy. But what can happen to reflected energy has been
known for decades in the field of optical physics. The reflection that
one sees in a mirror contains an ExH power density that activates
one's human retina. Waves cannot exist without energy. Standing waves
cannot exist without forward and reverse traveling waves. That some
otherwise knowledgeable and influential RF gurus deny the reality of
such is really sad.

What they are missing is simple. The FSU web page describes how wave
cancellation redistributes the reflected energy back toward the load
from what is essentially a Z0-match. The redistribution of reflected
energy due to wave cancellation is technically NOT a re-reflection
since it involves destructive interference between TWO waves. When the
RF gurus broaden their knowledge base to include wave cancellation,
they will alleviate their ignorance on how reflected energy is
redistributed back toward the load. That knowledge can be obtained
from any good optics reference book including "Optics", by Hecht and
"Principles of Optics", by Brown and Wolf. Until those gurus admit to
themselves that they are not omniscient, the argument will continue.

I finished reading Cecil's article (http://www.w5dxp.com/nointfr.htm)

Remember that article describes the two special cases where the two
superposed waves are 90 degrees apart and therefore do not interfere
with each other, i.e. no wave cancellation exists. I have not yet
written the other two articles about constructive and destructive
interference.
--
73, Cecil, w5dxp.com

On May 26, 6:59*am, Cecil Moore wrote:
That knowledge can be obtained
from any good optics reference book including "Optics", by Hecht and
"Principles of Optics", by Brown and Wolf.

Continuing after taking my wife to work:

The reason that optical physicists know so much more about energy
transfer than RF gurus is that the optical physicists do not have the
luxury of measuring the voltage and current associated with an EM wave
at light frequencies. They have historically been forced to deal with
irradiance, i.e. power density, at every step of their analysis since
that is the only thing they could easily quantize through
measurements. As a result, they know everything one needs to know
about where the energy goes during reflection and wave cancellation.
If one wants to catch up on such as it applies to all EM waves,
including RF waves, please obtain a copy of "Optics", by Hecht and
read the chapters on superposition and interference. It was an eye
opener for me and resulted in my WorldRadio energy analysis article.

http://www.w5dxp.com/energy.htm

Optical physicists usually make power density (irradiance)
measurements and then calculate the electric and magnetic fields of
the EM wave. RF gurus make voltage and current measurements and ignore
energy/power except for net power in and net power out thus losing
important details in the process. When they don't understand energy
transfer, they dismiss it as unimportant or worse yet, assume that
their ignorance somehow proves something as W7EL has done in his "food
for thought" article on forward and reflected power. All that he has
succeeded in proving is his ignorance of partial or total wave
cancellation involving two superposed component waves which can
reverse the flow of energy in a transmission line just as easily as
can an actual reflection. Here is a diagram of the energy flow at a 50-
ohm Z0-match as is common in ham installations.

http://www.w5dxp.com/enfig3.gif

Pref1 = Zero = P3 + P4 - 2*SQRT(P3*P4)

where P3=P4 and the two electric fields are 180 degrees out of phase.
This is total destructive interference due to wave cancellation, i.e.
out-of-phase superposition.

Pfor2 = P1 + P2 + 2*SQRT(P1*P2)

This total constructive interference due to in-phase superposition.

If W7EL would use the general power density equation on his "food-for-
thought" examples

Ptot = P1 + P2 + 2*SQRT(P1*P2)cos(theta)

he would obtain all the correct answers as to where the reflected
energy goes, i.e. the energy analysis would agree exactly with his
voltage analysis. That energy analysis would tell us exactly how much
reflected power is absorbed in the source resistor and exactly how
much is redistributed back toward the load as part of the forward
wave. But when W7EL heard these facts of physics from the field of EM
wave optics many years ago, he said "Gobbleygook".
--
73, Cecil, w5dxp.com

On 26 mayo, 02:26, Richard Clark wrote:
On Tue, 25 May 2010 20:41:45 -0700 (PDT), lu6etj
wrote:

eight years it is a lot of time for not having arrived to a
consent!

Hi Miguel,

You got on this train rather late if all you see is eight years of it.
The circular references have entertainment value - so did vaudeville.

73's
Richard Clark, KB7QHC

Hi Richard

You got on this train rather late if all you see is eight years of it.

I am not mean that!

I clearly said=

"Always has been a pleasure for me to read you. I have learning very
much from your enthusiastic discussions. You made me think of things
that I never thought without your help. Thank you."

Miguel

On May 26, 2:33*pm, lu6etj wrote:
On 26 mayo, 02:26, Richard Clark wrote:

On Tue, 25 May 2010 20:41:45 -0700 (PDT), lu6etj
wrote:

eight years it is a lot of time for not having arrived to a
consent!

Hi Miguel,

You got on this train rather late if all you see is eight years of it.
The circular references have entertainment value - so did vaudeville.

73's
Richard Clark, KB7QHC

Hi Richard

You got on this train rather late if all you see is eight years of it.

I am not mean that!

I clearly said=

"Always has been a pleasure for me to read you. I have learning very
much from your enthusiastic discussions. You made me think of things
that I never thought without your help. Thank you."

Miguel

Cecil, have forgotten that because the source resistance of the RF
power amp is non-dissipative, none of the reflected power is absorbed
therein?

Walt

On May 26, 1:56*pm, walt wrote:
Cecil, have forgotten that because the source resistance of the RF
power amp is non-dissipative, none of the reflected power is absorbed
therein?

Actually, this discussion is based on an example introduced by W7EL
which assumed a 50 ohm source resistor in his "food for thought,
forward and reflected power" article posted on his web page. The
source resistance of an actual RF power amp doesn't matter. W7EL's
example specified a 50 ohm resistor as the source impedance.

http://eznec.com/misc/Food_for_thought.pdf
--
73, Cecil, w5dxp.com

On 26 mayo, 11:09, Cecil Moore wrote:
On May 26, 6:59*am, Cecil Moore wrote:

That knowledge can be obtained
from any good optics reference book including "Optics", by Hecht and
"Principles of Optics", by Brown and Wolf.

Continuing after taking my wife to work:

The reason that optical physicists know so much more about energy
transfer than RF gurus is that the optical physicists do not have the
luxury of measuring the voltage and current associated with an EM wave
at light frequencies. They have historically been forced to deal with
irradiance, i.e. power density, at every step of their analysis since
that is the only thing they could easily quantize through
measurements. As a result, they know everything one needs to know
about where the energy goes during reflection and wave cancellation.
If one wants to catch up on such as it applies to all EM waves,
including RF waves, please obtain a copy of "Optics", by Hecht and
read the chapters on superposition and interference. It was an eye
opener for me and resulted in my WorldRadio energy analysis article.

http://www.w5dxp.com/energy.htm

Optical physicists usually make power density (irradiance)
measurements and then calculate the electric and magnetic fields of
the EM wave. RF gurus make voltage and current measurements and ignore
energy/power except for net power in and net power out thus losing
important details in the process. When they don't understand energy
transfer, they dismiss it as unimportant or worse yet, assume that
their ignorance somehow proves something as W7EL has done in his "food
for thought" article on forward and reflected power. All that he has
succeeded in proving is his ignorance of partial or total wave
cancellation involving two superposed component waves which can
reverse the flow of energy in a transmission line just as easily as
can an actual reflection. Here is a diagram of the energy flow at a 50-
ohm Z0-match as is common in ham installations.

http://www.w5dxp.com/enfig3.gif

Pref1 = Zero = P3 + P4 - 2*SQRT(P3*P4)

where P3=P4 and the two electric fields are 180 degrees out of phase.
This is total destructive interference due to wave cancellation, i.e.
out-of-phase superposition.

Pfor2 = P1 + P2 + 2*SQRT(P1*P2)

This total constructive interference due to in-phase superposition.

If W7EL would use the general power density equation on his "food-for-
thought" examples

Ptot = P1 + P2 + 2*SQRT(P1*P2)cos(theta)

he would obtain all the correct answers as to where the reflected
energy goes, i.e. the energy analysis would agree exactly with his
voltage analysis. That energy analysis would tell us exactly how much
reflected power is absorbed in the source resistor and exactly how
much is redistributed back toward the load as part of the forward
wave. But when W7EL heard these facts of physics from the field of EM
wave optics many years ago, he said "Gobbleygook".
--
73, Cecil, w5dxp.com

Hi Cecil

Continuing after taking my wife to work:

Yo have a chopper, I have a chopper. Your wife go to work, my wife go
to work. Are you my big brother? (older brother? = "hermano mayor",
in spanish) :D
....
Dr. Corum tells us what the problem is: "Lumped circuit theory fails
because it's a *theory* whose presuppositions are inadequate.

Well... "theories" are theories, models of "reality". As Einstein
said: "free creations of the human mind" = Newton's gravity theory,
Einstein's gravity theory...
Einstein one of course it is more accurate in certain situations, but
we still using Newton's laws to send spacecrafts to Mars. As in the
Sears-Zemansky example given, they coexist and it can solve differents
problems.
Velocity adding fails at very high speeds ("presuppositions are
inadequate") and we need relativity, but for common situations it is
not necessary use the last one (of course you know it, it is only a
note). It is easy for us become tempted to think that Einstein one it
is the "true" theory and not "a better aproximation to reality"
theory.

As some of us agree "all models are false", then, perhaps --only
"perhaps"-- (I do not want offend to anyone) some of the others models
presented by our distinguished colleages could not be as precise for
certain special situations, but still quite adequate to solve problems
or explain more simple things, as a Newton laws or "charges in
movement"...

As in other physics laws, it is not possible to reach a similar
consensus here in this regard? Models given, leads to wrong numbers or
failed to agree with empiric data?

Your examples, Cecil, gve me a light, now I have in my mind three
models that (for me) describe "reality" so good. With yours I can
think in forward and reflected power flowing simultaneously on Rs -not
contradiction-
Adding phasors of the forward and reflected travelling waves before
the last one reach generator, this one sees different Z line input and
not any reflected power there is circulating on it (not contradiction
to me) = "adding" in my human mind, of course. Reality only God/Allah/
Yahweh/Manitou/The Force/Zeus, knows- :) .

I'm not trying to be syncretic. Same cat, different models... Is it
not possible that?

73

Miguel Ghezzi LU6ETJ

On Wed, 26 May 2010 11:33:08 -0700 (PDT), lu6etj
wrote:

"Always has been a pleasure for me to read you. I have learning very
much from your enthusiastic discussions. You made me think of things
that I never thought without your help. Thank you."

Hi Miguel,

You are welcome.

My comments (beyond your quote above) were in regard to you observing
the amount of time Walt's topic has been under discussion. In fact,
the agony of source resistance has been painfully with us for as long
as newsgroups could support the noise bandwidth.

As dangerous as unasked-for advice is, prepare something at your bench
to measure all these contentious issues for yourself. Force the
issues that are only being discussed rather than measured. Discover
the roots of what used to be a "hands on" avocation. Learn the
practical reality in relation to the academic meaning. Discover the
first principles by making mistakes and having failures that you can
correct in front of you, instead of being assisted by an "expert."
Compare results with like-minded bench workers who can perform the
same examinations you are doing.

This is what Walt did - many times. His bench work eclipses ALL
discussion of theory. The irony that inhabits this is that his bench
work may even eclipse his own explanations. Absolutely no one else
has dared to slide up to the bench to demonstrate that, however. The
level of "critique" is much like ants scattering at the feet of a
giant.

There is a lot of math thrown against the wall to prove something. It
may or may not be the same thing. What it does prove is:
"Models are doomed to succeed."
This is demonstrated here at least once a week on average, and is even
held up as a hallmark of hazing, initiation, or anti-intellectual
snobbery. Math/Models/Simulations/Theories serve many religious wars.

73's
Richard Clark, KB7QHC

On May 26, 4:23*pm, lu6etj wrote:
I'm not trying to be syncretic. Same cat, different models... Is it
not possible that?

Yes, except that W7EL uses the inadequacy of his model to prove that
his model yields contradictory results. I freely admit that his model
is inadequate and contradictory which implies that he is using the
wrong model.
--
73, Cecil, w5dxp.com

On 25 mayo, 11:49, Cecil Moore wrote:
On May 24, 10:31*pm, lu6etj wrote:

Anyway, my question is about validity of the assertion that reflected
wave -in that example- IS ABSORBED by the pad. According to my simple
calculations this hipothesis, as I see it, it does not coincide with
my early learnings.

Miguel, let's switch your example over to an easier to understand
example. Assume an ideal signal generator equipped with a resistive
circulator load. Let's call such a device an SGCR, a Signal Generator
equipped with a Circulator and a Resistor. Assume that 100% of the
reflected energy is dissipated in the circulator load resistor (none
re-reflected) and none of the reflected energy reaches the source. So
here is the block diagram.

SGCR--------feedline--------load

That model should be easier to discuss than the pad attenuator model.
What do you think?
--
73, Cecil, w5dxp.com

Excuse me Cecil:

I am reading this newsgroup through Google groups web page and I just
realized that later replies to previous post are intercalated in the
thread, while I expected to see it always at the end of it, for that
reason I did not ACK before to it. (I hope yours be the only one, I
will review all thread tho chek for others).

In a early post I wrote = "of course if we insert a circulator to
separate both powers, generator now would see 1 ohm load, could
develope 1 W incident, 0 W reflected (Pn=1W) on circulator input, 0.36
W would be outputting on the other port to render 0.64 W (Pn) to the
load with 1 W Pf and 0,36 W Pr again"
Is this result OK for you?.

The thread advance toward more deeper issues since :), and now I have
been analizing all the matter because it quickly superceed my original
doubt. A few minutes ago had started to read your article (http://
www.w5dxp.com/energy.htm) and the Roy's one (http://eznec.com/misc/
Food_for_thought.pdf) and yesterday I have been reloading my old
"Transmission lines antennas and wave guides" from King, Mimno & Wing
to review the issue from that classical perspective.

I am interested in your optic analogy, I can imagine the load as a
partially reflecting surface, real part of it as absorbance
(transmittance if it was a radiator). line as a unidimensional medium
and reflection as the form of "redistribute energy" (is it OK?) and a
coherent light source for the voltage source, but I am still trying to
visualze the optical equivalent of source resistance and its job to be
a good analog, Also I am interested in check other values and
conditions in your other article (first part) with 45 degree line.

Thank you very much for your helping and inspiration.

73 - Miguel LU6ETJ

On May 27, 9:50*am, lu6etj wrote:
I am reading this newsgroup through Google groups web page and I just
realized that later replies to previous post are intercalated in the
thread, while I expected to see it always at the end of it, for that
reason I did not ACK before to it. (I hope yours be the only one, I
will review all thread tho chek for others).

I am also using Google since ATT dropped Usenet. I liked Thunderbird a
lot better than Google's usenet interface but I am adapting. The above
information is good to know. Thunderbird has a way to keep up with
unread vs read postings but Google doesn't seem to - at least I don't
know how to do it on Google.

In a early post I wrote = "of course if we insert a circulator to
separate both powers, generator now would see 1 ohm load, could
develope 1 W incident, 0 W reflected (Pn=1W) on circulator input, 0.36
W would be outputting on the other port to render 0.64 W (Pn) to the
load with 1 W Pf and 0,36 W Pr again"
Is this result OK for you?.

The SGCR source is usually designed for 50 ohms, i.e. the signal
generator always "sees" a 50 ohm load because it does not "see" any
reflected energy. The ideal circulator is usually designed with 50 ohm
line and a 50 ohm load resistor. If we could stick with that
particular configuration for the SGCR source, it would aid in my
understanding what is the actual system configuration, i.e. not your
fault but I am confused by your above posting.

I am interested in your optic analogy, I can imagine the load as a
partially reflecting surface, real part of it as absorbance
(transmittance if it was a radiator). line as a unidimensional medium
and reflection as the form of "redistribute energy" (is it OK?) and a
coherent light source for the voltage source, but I am still trying to
visualze the optical equivalent of source resistance and its job to be
a good analog, Also I am interested in check other values and
conditions in your other article (first part) with 45 degree line.

I don't think a laser source handles reflected energy like an RF amp
does. So, to start with, let's avoid reflected energy being incident
upon the laser source. Here is a good example to start with, a 1/4WL
non-reflective coating on glass.

Laser-----air-------|--1/4WL thin-film, r = 1.2222---|---Glass, r =
1.4938---...

The 1/4WL thin-film coating on the glass acts exactly like a 1/4WL
matching section of transmission line. Reflections at the air to thin-
film interface are eliminated by wave cancellation just as the FSU web
page says,

micro.magnet.fsu.edu/primer/java/scienceopticsu/interference/
waveinteractions/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."

Note that the reflection coefficient, r, is 1.0 for air. Thus the
SQRT[(1.0)(1.4938)] = 1.2222 ensures that reflections are eliminated
by the r = 1.2222 thin-film coating.

The same thing happens at the '+' Z0-match in the following RF system.

XMTR---50 ohm coax---+---1/4WL 300 ohm feedline---1800 ohm load

Note that SQRT[(50)(1800)] = 300 ensuring that reflections are
eliminated.
--
73, Cecil, w5dxp.com