Current across the antenna loading coil - from scratch
 

W8JI Wrote:
The current you measure with a clamp on meter or any other reliable
current meter that does not greatly perturb the circuit is the current
that causes radiation, it is the current that causes heating, and it is
the current we would use to calculate power.

Cecil Moore wrote:
There's absolutely no argument about that. Both forward waves and
reflected waves radiate so standing waves obviously radiate. Both
forward waves and reflected waves cause I^2*R losses. Stating such
obvious technical facts is a diversion and a waste of words.

Cecil,

Please humor all of us.

You now seem to agree the current we measure, which is the current that
causes radiation, causes heating, and that we can use to determine
phase or power levels is what Roy, I, and a dozen others have been
saying.

So what exactly is the importance of this current YOU are talking
about? Since it does not cause radiation, does not cause heat, and does
not determine phase....exactly what does it do?

73 Tom

Current across the antenna loading coil - from scratch
 

Cecil Moore wrote:

Please explain the results posted at: http://www.qsl.net/w5dxp/travstnd.GIF

Cecil,

You may believe it is obvious, but it is not quite clear what you are
trying to show in that figure. On the left side, traveling wave, it
appears that "magnitude" means Io. On the right side, standing wave, it
appears that "magnitude" means Io cos(kx).

The gist of your position seems to be that somehow the traveling wave is
more powerful, or at least different, since the area under the current
magnitude curve is larger. In reality, however, it is necessary to pick
a single time at which to compare the two cases. It is of little value
to look at some sort of overall envelope for the traveling wave. The
correct magnitude of the traveling wave never has the shape of the
overall envelope. Pick a single time, say when wt is equal to zero or
equal to pi. Then compare the curves. In fact, if you pick any single
time for the left side the resulting curve shape will look a lot like
the right side.

73,
Gene
W4SZ

Current across the antenna loading coil - from scratch
 

Current across the antenna loading coil - from scratch
 

wrote:
So what exactly is the importance of this current YOU are talking
about?

All the diversionary BS trimmed from your posting. Bottom line,
the equation for standing wave current is:

I(x,t) = Io*cos(kx)*cos(wt)

The equation for traveling wave current is:

I(x,t) = Io*cos(ks+wt)

Since you obviously don't comprehend the difference, please
dust off your old math book and take a look.

In case you need a graphics reference for those two equations,
you can find it at: http://www.qsl.net/w5dxp/travstnd.GIF

You will find the two above currents are virtually opposites
of each other.

In particular, standing wave current phase CANNOT be used to
determine the phase shift through a wire or through a coil
because its phase never changes in a 1/4WL monopole.

I can hardly say it better than Gene Fuller who said:
Regarding the cos(kz)*cos(wt) term in a standing wave:

Gene Fuller, W4SZ wrote:
In a standing wave antenna problem, such as the one you describe, there is no
remaining phase information. Any specific phase characteristics of the traveling
waves died out when the startup transients died out.

Phase is gone. Kaput. Vanished. Cannot be recovered. Never to be seen again.

The only "phase" remaining is the cos (kz) term, which is really an amplitude
description, not a phase.

Please tell us what it is about Gene's posting that you don't
understand.
--
73, Cecil http://www.qsl.net/w5dxp

Current across the antenna loading coil - from scratch
 

Gene Fuller wrote:
You may believe it is obvious, but it is not quite clear what you are
trying to show in that figure. On the left side, traveling wave, it
appears that "magnitude" means Io. On the right side, standing wave, it
appears that "magnitude" means Io cos(kx).

No, both plots are for I(x,t). The magnitude of the traveling wave
current is constant while the phase changes with 'x'. The phase of
the standing wave current is constant while the magnitude changes
with 'x'. They are virtually opposites of each other.

It is of little value
to look at some sort of overall envelope for the traveling wave.

Both currents are phasor RMS values along with their phases.

I am reporting *exactly* what EZNEC reports. If you don't like
that, talk W7EL into reporting something different.
--
73, Cecil http://www.qsl.net/w5dxp

Current across the antenna loading coil - from scratch
 

Cecil Moore wrote:
wrote:

So what exactly is the importance of this current YOU are talking
about?


All the diversionary BS trimmed from your posting. Bottom line,
the equation for standing wave current is:

I(x,t) = Io*cos(kx)*cos(wt)

The equation for traveling wave current is:

I(x,t) = Io*cos(ks+wt)

Since you obviously don't comprehend the difference, please
dust off your old math book and take a look.

In case you need a graphics reference for those two equations,
you can find it at: http://www.qsl.net/w5dxp/travstnd.GIF

You will find the two above currents are virtually opposites
of each other.

In particular, standing wave current phase CANNOT be used to
determine the phase shift through a wire or through a coil
because its phase never changes in a 1/4WL monopole.

I can hardly say it better than Gene Fuller who said:
Regarding the cos(kz)*cos(wt) term in a standing wave:

Gene Fuller, W4SZ wrote:

In a standing wave antenna problem, such as the one you describe,
there is no remaining phase information. Any specific phase
characteristics of the traveling waves died out when the startup
transients died out.

Phase is gone. Kaput. Vanished. Cannot be recovered. Never to be seen
again.

The only "phase" remaining is the cos (kz) term, which is really an
amplitude description, not a phase.


Please tell us what it is about Gene's posting that you don't
understand.

Cec;

Please answer the man's question. Don't prevaricate. Don't deviate.
Answer the damn question.

Except for this particular subject I have great admiration for you
knowledge and have learned from you. This subject seems to be your
bugaboo. I have completely lost track of what the object of the exercise is.

Dave N

Dave N

Current across the antenna loading coil - from scratch
 

Cecil Moore wrote:
Gene Fuller wrote:

You may believe it is obvious, but it is not quite clear what you are
trying to show in that figure. On the left side, traveling wave, it
appears that "magnitude" means Io. On the right side, standing wave,
it appears that "magnitude" means Io cos(kx).


No, both plots are for I(x,t). The magnitude of the traveling wave
current is constant while the phase changes with 'x'. The phase of
the standing wave current is constant while the magnitude changes
with 'x'. They are virtually opposites of each other.

It is of little value to look at some sort of overall envelope for the
traveling wave.


Both currents are phasor RMS values along with their phases.

I am reporting *exactly* what EZNEC reports. If you don't like
that, talk W7EL into reporting something different.

Cecil,

Perhaps I was not clear. I understand the plots, and I have no question
that they show what EZNEC provides.

My question is why you feel there is anything of significance or
anything for the "gurus" to ponder.

As I explained, the curves are mostly a comparison of apples to oranges.
One (standing wave) shows the peak current at when the cos(wt) factor is
at a maximum. The other (traveling wave) shows the envelope of all the
current shapes over time. They are really two different entities, and
they have virtually no application to the topic featured in the past
17,000 messages.

What you call the "magnitude" of the traveling wave never actually
represents the current over the length of wire at any point in time.

73,
Gene
W4SZ

Current across the antenna loading coil - from scratch
 

Roy Lewallen wrote:

So for starters, why don't you explain how your theory fits with the
existing model results? Why is the current drop the same with an antenna
and for a lumped circuit? Why does removing ground make the current drop
go away? Why is there no significant phase shift in current from bottom
to top? Conventional theory can explain this. Can yours?

As for your promise to write the article, I have to point out that
you've made this promise before without delivering. So I'm not exactly
holding my breath waiting for it. I'm sure it'll make interesting
reading, though, and it's a revolutionary enough theory that the IEEE,
or at the very least QEX, should be happy to publish it when it's
finally complete.

Roy Lewallen, W7EL

Roy, I will make you a bet. Lunch, if you might be at Central States
this year.

Not Gonna Happen.

They are not interested in reality. They are not interested in
engineering. They do not want to understand physics, or they are not
capable. It matters not.

I have been watching, and reading, and would like to see you, and the
others, stop beating a very dead horse. Cecil and Yuri will never get it.

Tom
K0TAR

Current across the antenna loading coil - from scratch
 

Gene Fuller wrote:
You may believe it is obvious, but it is not quite clear what you are
trying to show in that figure.

Gene, I previously responded in words that I thought you would
understand, based on your previous understanding. It occurred
to me during my walk that not every reader is an engineer, not
every engineer is a EE, and not every EE also has a math degree.

Here it is in easier to understand terms. Given the 1/4WL conductor
and the web page at:

http://www.qsl.net/w5dxp/travstnd.GIF

The way to measure phase shift through a wire carrying the
traveling wave current is to put a current probe at location
A and location B, and measure the phase shift between those
two equal magnitude sine waves. If a coil exists in the circuit,
that would also be the way to get a rough measure of the phase
shift across the coil.

Example: The phase shift from 30% to 60% in the traveling wave
antenna is taken from the tabular data as 54.2-27.6 = 26.6 degrees.

The phase information is in the *phase* in a traveling wave.

For the standing wave current, the situation is completely
different. The phase measured between any two current probes
will always be zero. The phase of a standing wave current is
useless for measuring phase shift. The way to extract the
phase information is to measure the *amplitude* at two points
and then calculate the phase shift by taking the arc-cos of
the normalized amplitude.

Example: The phase shift from 30% to 60% in the standing wave
antenna is arc-cos(0.8843) - arc-cos(0.5840) = 26.5 degrees.

The phase information is in the *amplitude* in a standing wave.

Thus in both antennas, the phase shift in 30 percent of the
wire is about 27 degrees. (90*.3 = 27) If we had a coil installed
in that 30 degrees of the antenna instead of a wire, the same
concepts would apply.
--
73, Cecil http://www.qsl.net/w5dxp

Current across the antenna loading coil - from scratch
 

David G. Nagel wrote:
Please answer the man's question. Don't prevaricate. Don't deviate.
Answer the damn question.

Maybe one of my other postings answers the question for you.
I'm not prevaricating or deviating. I'm answering the questions
to the best of my ability. Gene's posting is one of the best
answers to Tom's questions that I have seen. Gene says there is
ZERO information in standing wave phase. I agree with Gene.

Except for this particular subject I have great admiration for you
knowledge and have learned from you. This subject seems to be your
bugaboo. I have completely lost track of what the object of the exercise
is.

The object of the exercise is to prove that standing wave current
phase cannot be used to measure the phase through a wire or coil
or anything else. The phase of a standing wave is already known
and is unchanging. The only phase information in a standing wave
current is contained in the amplitude.
--
73, Cecil http://www.qsl.net/w5dxp