Standing-Wave Current vs Traveling-Wave Current
 

On Wed, 2 Jan 2008 06:14:58 -0500, "David J Windisch"
wrote:

What's the status on that DC long-line 'tween somewhere in your neck of the
woods south toward Baja, pls? Kind regards on behalf of all the lurkers
from Dave N3HE

?????

Hi Dave,

That is pretty obscure, which means you know more than I do.

On the other hand, the long-line to DC for me a few days ago was
American Airlines SEA to BWI; then back from National; both through
DFW.

73's
Richard Clark, KB7QHC

Standing-Wave Current vs Traveling-Wave Current
 

Roy Lewallen wrote:
So far I haven't seen any analysis using alternative theories, ideas of
how sources work, or using power waves, which also correctly predict the
voltage at all times and in steady state.

This is hardly different from the other example. Total destructive
interference is still occurring in the source resistor resulting
in total constructive interference toward the load. The forward
and reflected powers are equal to 0.04 watts. All of the voltages
and currents are easy to calculate after that. What else do you
need to know?
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

On Wed, 2 Jan 2008 05:04:17 -0800 (PST), Keith Dysart
wrote:

Given your previous writings, I suspect that you have
a solid understanding of the behaviour of an open-circuited
transmission line excited with a step function.

Hi Keith,

I do, but I haven't dwelled on the matter too much since my days in
RADAR where a Pulse Forming Network could provide a kick from a very
big bottled Thyratron. I can also in those early days recall an
inadvertent opening of a circuit to a constant current device -
another kick.

As for naming the multitude of combined stepped wave shapes, front
porch and back porch regularly make their appearances a Trillion times
an hour.

I simply couldn't wade through the myriad issues that you were trying
to pull together. I prefer to drill down on one thing at a time and
then bring them together. For instance, your last example of dueling
sources was clearly blighted and allowed for easy dismissal. However,
its inclusion was distinctly at odds with the other discussion which
reveals the hazard of the shotgun style of answering all of Cecil's
objections in one breath.

Cecil's crafted problems immediately fail with one detail, there is no
reason to pursue them all. One need only review the "purpose" of this
thread being
On Tue, 18 Dec 2007 09:33:23 -0600, Cecil Moore wrote:

There seems to be mass confusion even among the gurus on
this newsgroup as to the difference between standing-wave
current, as exists on a 1/2WL dipole, vs traveling-wave
current, as exists on a terminated antenna like a rhombic.
Clearly, Cecil was the most dazed and confused guru when I drilled
down on this "purpose" of his own choice, on his own terms. The
subsequent 450 postings have merely roiled in the seascape on sloshing
waves when this anchor of "purpose" was cast off.

Perhaps you could make an attempt at writing a clear
description of the behaviour of such a system in terms
of charge flow and storage. Since "wave" is a word
overloaded with meanings, it would be good not to use
it in the description.

I can appreciate your attempt to confine it to charge flow, but for me
that leading edge merely introduces a wide spectrum of RF rather than
restricting the topic. If I were to give any thought to the minutia
of current flow along infinitesimal sections, it has long since been
focused in the realm of coulomb blockades at the nano scale of quantum
dots, and where sound waves comfortably migrate in the 100s of THz. I
think few (make that zero) here are terribly interested in that
side-bar.

Once a clear description exists, I can extend it
using the same clear terminology to illustrate
the points of interest.

Methinks you are going to suffer it being ignored by the target of
your intentions (Cecil?). His affliction of Netzheimers only allows
any topic to be discussed to its logical confusion.

If, for the sake of lurkers, any topic merits an indepth study, it is
best left to publishing at a page. I committed several hundred pages
to fractals in the past, and Chip never manage to summon up more than
half a dozen; and certainly never any coherent theory. Drilling down
on the supporter's stated interest, on his own terms, almost always
rents open the seams of failure. Again, the points of interest I
elaborated on were consumed by the very few (maybe two, and mostly to
their astonishment of so much effort going to so much "so what?"). We
can all agree that the march of time has ravaged any millennium
aspirations of the dawn of the fractal age.

73's
Richard Clark, KB7QHC

Standing-Wave Current vs Traveling-Wave Current
 

Roy Lewallen wrote:
I've completely accounted for the power and energy leaving the voltage
source, being dissipated in the resistor, and entering the line, at all
times from startup to steady state, and done it quantitatively with
numerical results. And I did this without any mention of propagating
waves of power or energy.

Yes, you did deliberately avoid mentioning the energy in
the forward and reflected waves in the stub. So what? The
energy supplied to the stub is in the form of EM wave
energy. As long as it is not transformed into a different
type of energy, it will remain EM energy whether you choose
to ignore it or not. Your failure to mention ExH energy/sec
doesn't mean it ceases to exist. The EM wave energy is still
there moving at the speed of light in the medium. It is exactly
equal to the energy necessary to support the forward and
reflected power.

Roy, if you think that your failure to mention reality changes
reality, I feel really sorry for you but it is not unusual for
gurus to suffer from delusions of grandeur.
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

On Jan 2, 1:50*pm, Cecil Moore wrote:
Roy Lewallen wrote:
I've completely accounted for the power and energy leaving the voltage
source, being dissipated in the resistor, and entering the line, at all
times from startup to steady state, and done it quantitatively with
numerical results. And I did this without any mention of propagating
waves of power or energy.

Yes, you did deliberately avoid mentioning the energy in
the forward and reflected waves in the stub. So what? The
energy supplied to the stub is in the form of EM wave
energy. As long as it is not transformed into a different
type of energy, it will remain EM energy whether you choose
to ignore it or not.

In a stub driven with a step function, where is the
energy stored?

...Keith

Standing-Wave Current vs Traveling-Wave Current
 

Keith Dysart wrote:
But do not expect the power dissipated in the resistor
to increase by the same amount as the "reflected power".
In general, it will not. This is what calls into question
whether the reflected wave actually contains energy.

Virtually every EM wave you see with your own eyes is
a reflection. For you to argue that there is no energy
in those reflected EM waves is ridiculous in the extreme.
Exactly how do your optic nerves detect photons that
contain no energy? Hey, maybe that's why you are
hallucinating. :-)

This again calls into question the concept of power
in a reflected wave, since there is no accounting
for where that "power" goes.

That you fail to understand where the EM reflected wave
energy goes is simply ignorance. Please alleviate your
ignorance on the subject and the problem will go away.
Optical physicists have been tracking that energy for
centuries. Where have you been for the past three
centuries? :-)

I suggest you start with Eugene Hecht's chapter on
interference in "Optics". You will learn about
destructive interference, constructive interference,
and why those two must balance. All of the ExH energy
in an EM wave is conserved. You are simply ignorant
of how that energy is conserved.
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Keith Dysart wrote:
Perhaps you could make an attempt at writing a clear
description of the behaviour of such a system in terms
of charge flow and storage.

Since you are unable to understand the more simple example
using only one sine wave, what makes you think you are
capable of understanding the more complex step function?
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Keith Dysart wrote:
I am not sure you have the methodology quite correct.
The source is not turned off; its output is set to 0.

That's exactly the same thing - turning a source off
and setting it to zero. I suggest you go back and
study the rules for superposition and get back to us.
Exactly the same concepts apply for an s-parameter
analysis. Please learn how s11 and s22 are measured
and get back to us.
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Keith Dysart wrote:
But this same information has been repeatedly provided
and ignored. Will this time be different?

I'm not the one who is ignoring that information.
Where are your calculations involving destructive
and constructive interference? Until you provide
that information, you are just blowing smoke.

When are you going to realize that the effective
reflection coefficient for a source supplying zero
power is |1.0|?

You can certainly use the reflection coefficient
that you posted but that is only a small part of
the total reflection story.
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Keith Dysart wrote:
Cecil Moore wrote:
There can be a large difference in the output
impedance of an amplifier designed to drive a 50 ohm
load and a 50 ohm Thevenin equivalent circuit.

Then your Thevenin circuit is not an equivalent
for the amplifier, is it?

No it isn't! So why are you trying to stuff it down
my throat?
--
73, Cecil http://www.w5dxp.com