On Jun 11, 12:09*pm, Roy Lewallen wrote:

But why would you expect the "reflected power" to have a different
effect when the transmission line is a quarter wavelength than when it's
a half wavelength?

If reflected power is fictitious, and the number wavelengths of
transmission line of any random impedance compared to the load
connected to it makes no difference in the load seen by the
transmitter, the output power produced by the transmitter, and the
power dissipated in the far-end termination, then what is the reason
you chose a 1/2 wavelength of transmission line in your quoted post?

RF

On Jun 11, 12:29*pm, Richard Fry wrote:

If reflected power is fictitious, etc

Followup: Those denying the existence of reflected signals within an
antenna system may wish to view the measurement of such signals, at
the link below.

http://i62.photobucket.com/albums/h8...easurement.gif

RF

On Jun 11, 12:56*pm, Richard Fry wrote:
Followup: *Those denying the existence of reflected signals within an
antenna system may wish to view the measurement of such signals, at
the link below.

Or at this link. Scroll down to "Using Dielectric Beamsplitters to
find the "missing energy" in destructive interference".

http://www.teachspin.com/instruments...eriments.shtml

I guarantee that every optical physicist who is reading this thread is
laughing at the ignorance of the alleged RF gurus.
--
73, Cecil, w5dxp.com

On 11 jun, 16:27, Cecil Moore wrote:
On Jun 11, 12:56*pm, Richard Fry wrote:

Followup: *Those denying the existence of reflected signals within an
antenna system may wish to view the measurement of such signals, at
the link below.

Or at this link. Scroll down to "Using Dielectric Beamsplitters to
find the "missing energy" in destructive interference".

http://www.teachspin.com/instruments...eriments.shtml

I guarantee that every optical physicist who is reading this thread is
laughing at the ignorance of the alleged RF gurus.
--
73, Cecil, w5dxp.com

Hello, here we are...! :)

At the risk of naïve and conciliatory I still thinking that to some
extent this is a problem of "same cat seen from different points of
view".

What if the question is formulated in terms apart, for example =
generator responses to load differences, and by what mechanism a
transmission line transforms impedances to presents to the generator
those different loads?
In that formulation I think there are room to simple, basic, and
understandable electrical laws to account for generator behaviour and
TL travelling waves interference phenomenom to account for Z
transformings.

From my perspective your main differences are reducible

73

Miguel Ghezzi - LU6ETJ

On Jun 11, 10:03*pm, lu6etj wrote:
On 11 jun, 16:27, Cecil Moore wrote:

On Jun 11, 12:56*pm, Richard Fry wrote:

Followup: *Those denying the existence of reflected signals within an
antenna system may wish to view the measurement of such signals, at
the link below.

Or at this link. Scroll down to "Using Dielectric Beamsplitters to
find the "missing energy" in destructive interference".

http://www.teachspin.com/instruments...eriments.shtml

I guarantee that every optical physicist who is reading this thread is
laughing at the ignorance of the alleged RF gurus.
--
73, Cecil, w5dxp.com

Hello, here we are...! *:)

At the risk of naïve and conciliatory I still thinking that to some
extent this is a problem of "same cat seen from different points of
view".

What if the question is formulated in terms apart, for example =
generator responses to load differences, and by what mechanism a
transmission line transforms impedances to presents to the generator
those different loads?
In that formulation I think there are room to simple, basic, and
understandable electrical laws to account for generator behaviour and
TL travelling waves interference phenomenom to account for Z
transformings.

From my perspective your main differences are reducible

73

Miguel Ghezzi - LU6ETJ

of course, but that is no fun!

On Jun 11, 5:03*pm, lu6etj wrote:
From my perspective your main differences are reducible

The basic argument revolves around what math shortcuts can be used to
solve a particular problem vs what is actually happening in reality
according to the accepted laws of physics. I agree one doesn't
necessarily need to understand the laws of physics to solve a problem
but one should probably know enough physics to recognize when those
laws of physics are being violated by one's argument.
--
73, Cecil, w5dxp.com

On 11 jun, 23:26, Cecil Moore wrote:
On Jun 11, 5:03*pm, lu6etj wrote:

From my perspective your main differences are reducible

The basic argument revolves around what math shortcuts can be used to
solve a particular problem vs what is actually happening in reality
according to the accepted laws of physics. I agree one doesn't
necessarily need to understand the laws of physics to solve a problem
but one should probably know enough physics to recognize when those
laws of physics are being violated by one's argument.
--
73, Cecil, w5dxp.com
............
of course, but that is no fun!
I agree
......
As a courtesy to me, a foreigner tourist ham, would you mind stop for
a brief moment your more general differences and tell me if you agree
on the behavior of a Thevenin generator with a series resistance of 50
ohms in relation to changes in impedance of a lossless TL predicted by
the Telegrapher's equations solutions in terms of the power dissipated
on the load resistance and series resistence of Thevenin source?
I am pretty serious about this: until today I could not know if you
agree in that!! :)

On Jun 12, 4:24*am, lu6etj wrote:
On 11 jun, 23:26, Cecil Moore wrote: On Jun 11, 5:03*pm, lu6etj wrote:

From my perspective your main differences are reducible

The basic argument revolves around what math shortcuts can be used to
solve a particular problem vs what is actually happening in reality
according to the accepted laws of physics. I agree one doesn't
necessarily need to understand the laws of physics to solve a problem
but one should probably know enough physics to recognize when those
laws of physics are being violated by one's argument.
--
73, Cecil, w5dxp.com
...........
of course, but that is no fun!

I agree
.....
As a courtesy to me, a foreigner tourist ham, would you mind stop for
a brief moment your more general differences and tell me if you agree
on the behavior of a Thevenin generator with a series resistance of 50
ohms in relation to changes in impedance of a lossless TL predicted by
the Telegrapher's equations solutions in terms of the power dissipated
on the load resistance and series resistence of Thevenin source?
I am pretty serious about this: until today I could not know if you
agree in that!! :)

sure, if you properly apply the telegrapher's equations and the
thevenin equivalent methods. The real problem is that if you try to
do that for most amateur radio transmitters the source impedance is
not linear, and even worse may be time varying, which renders the
thevenin equivalent source substitution invalid.

Note though that in real world cases you need to use the full set of
equations, usually called by engineers the 'general transmission line
equations'. beware, some places may over simplify the telegrapher's
equations which may make them invalid in some cases. The
Telegrapher's equations (http://en.wikipedia.org/wiki/Telegrapher
%27s_equations), are often considered a subset of the 'General
transmission line equations (http://en.wikipedia.org/wiki/
Transmission_line) that are taught in distributed circuits and fields
and waves courses in engineering schools.

On Jun 11, 11:24*pm, lu6etj wrote:
As a courtesy to me, a foreigner tourist ham, would you mind stop for
a brief moment your more general differences and tell me if you agree
on the behavior of a Thevenin generator with a series resistance of 50
ohms in relation to changes in impedance of a lossless TL predicted by
the Telegrapher's equations solutions in terms of the power dissipated
on the load resistance and series resistence of Thevenin source?
I am pretty serious about this: until today I could not know if you
agree in that!! :)

Miguel, I don't think there is much disagreement about things that are
easily measured, like voltage and current. One solution to the
telegrapher's equations involves forward and reflected waves of
voltage and current. The conventional way of handling power (energy/
unit-time) is to use the voltages and currents to calculate the power
at certain points of interest. The telegrapher's equations do not tell
us *why* the power is what it is and the energy is where it is. To
obtain the why, one must study the behavior of electromagnetic waves.
How does the energy in electromagnetic waves behave? The telegrapher's
equations and Thevenin source do not answer that question.

For instance: Most readers here seem to think that the only phenomenon
that can cause a reversal of direction of energy flow in a
transmission line is a simple EM wave reflection based on the
reflection model. When they cannot explain what is happening using
that model, they throw up their hands and utter crap like, "Reflected
wave energy doesn't slosh back and forth between the load and the
source". But not only does it "slosh back and forth", it sloshes back
and forth at the speed of light in the medium because nothing else is
possible.

These are the people who have allowed their math models to become
their religion. They will not change their minds even when accepted
technical facts are presented. One response was, "Gobblydegook". (sic)

There is another phenomenon, besides a simple reflection, that causes
reflected energy to be redistributed back toward the load and that is
wave cancellation involving two wavefronts. If the two wavefronts are
equal in magnitude and opposite in phase, total wave cancellation is
the result which, in a transmission line, redistributes the wave
energy in the only other direction possible which is, surprise, the
opposite direction. This is a well known, well understood,
mathematically predictable phenomenon that happens all the time in the
field of optics, e.g. at the surface of non-reflective glass. It also
happens all the time in RF transmission lines when a Z0-match is
achieved.

Using the s-parameter equations (phasor math) at a Z0-match point in a
transmission line:

b1 = s11*a1 + s12*a2 = 0 = reflected voltage toward the source
Square this equation to get the reflected power toward the source.

These are the two wavefronts that undergo total wave cancellation,
i.e. total destructive interference.

b2 = s21*a1 + s22*a2 = forward voltage toward the load
s22*a2 is the re-reflection. Square this equation to get the forward
power toward the load.

If one squares both of those equations, one can observe the
interference terms which indicate why and where the energy goes. All
of the energy in s11*a1 and s12*a2 reverses direction at the Z0-match
and flows back toward the load. All the things that Roy is confused
about in his food-for-thought article on forward and reflected power
are easily explained by the power density equation (or by squaring the
s-parameter equations).

Ptot = P1 + P2 + 2*SQRT(P1*P2)*cos(A)
--
73, Cecil, w5dxp.com

On Jun 12, 2:26*am, Cecil Moore wrote:
On Jun 11, 5:03*pm, lu6etj wrote:

From my perspective your main differences are reducible

The basic argument revolves around what math shortcuts can be used to
solve a particular problem vs what is actually happening in reality
according to the accepted laws of physics. I agree one doesn't
necessarily need to understand the laws of physics to solve a problem
but one should probably know enough physics to recognize when those
laws of physics are being violated by one's argument.
--
73, Cecil, w5dxp.com

rather than worrying about basic physics, the real problem here is
that analysis of a non-linear circuit is being attempted using
techniques that are only valid for linear circuits.