Roy Lewallen wrote:
Before you get too carried away, look back in this thread where Cecil
posted a URL to his web site where he had an EZNEC (helical wire) model
of a coil at the base of a short whip. It showed significant current
drop from the bottom to the top, although no significant phase shift.

It showed a 10 degree phase shift. I've always said the phase
shift is what it is but it is NOT zero. 10 degrees is definitely
NOT zero even though you measured zero degrees shift. Wonder what
was wrong with your measurements?

So in
the course of developing your theory, you should explain why this
happens, since there are no longer the traveling and standing waves
which were on the whip.

Oh my, Roy, are you saying that zero ohms doesn't cause a reflection?
If so, your misconceptions are worse than I thought. A short to ground
causes exactly the same total reflection as an open-circuit, just with
different phases. I would have expected you to realize that.

I've looked very carefully at the models
and concluded that EZNEC is operating well within its capabilities, so
the results are valid.

Yes, they are and they shoot down your argument. Please explain
the results posted at: http://www.qsl.net/w5dxp/travstnd.GIF

So for starters, why don't you explain how your theory fits with the
existing model results?

You first, Roy, since you disagree with EZNEC.
--
73, Cecil http://www.qsl.net/w5dxp

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

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

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

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

Hopefully, I answered that question in my other posting. If one
wants to measure phase shift using a traveling wave current, one
measures the phase shift between two points.

If one wants to measure the phase shift using a standing wave
current, one measures the amplitudes at two points and subtracts
the arc-cosines of the normalized amplitude values.

You said essentially the same thing in your earlier posting -
that there is no phase information in the standing wave current
phase and all the phase information is in the amplitude values.
--
73, Cecil http://www.qsl.net/w5dxp

"Cecil Moore" wrote in message
m...
You said essentially the same thing in your earlier posting -
that there is no phase information in the standing wave current
phase and all the phase information is in the amplitude values.

thats the basic problem in this whole discussion. you are all talking about
the same thing, just using different notation and incomplete statements so
that none of you understands exactly what the others are trying to talk
about... when really you are all saying the same thing. its kind of like
after i graduated from college with an ee degree and my sister graduated
from an air force basic electronics course, she tried to ask me something
about currents in a transistor and i saw it all backwards... well of course
she was talking electron flow and i was talking hole flow. we both got the
same result but the notation was all different.

so, now i will raise my voice...

STOP THIS PETTY BICKERING AND GET OUT THERE AND USE AN ANTENNA INSTEAD OF
ARGUING ABOUT WHY THEY DON"T WORK THEY WAY YOU THINK THEY SHOULD!

Dave wrote:
... when really you are all saying the same thing.

Unfortunately, we are not all saying the same thing.
W7EL and W8JI are saying that using standing wave
current phase to make a phase shift measurement is
a valid approach. They keep reporting their results of
using such an approach as if it were a valid thing to
do. When those useless phase measurements are discarded,
the technical picture becomes a lot clearer.

I, and others, are saying that using a signal with
unchanging phase will not and cannot tell one anything
about any phase shift. There is no phase information
contained in the standing wave phase. All of the phase
information is contained in the standing wave magnitude.

I'm building a web page about this subject. The initial
graphic is at: http://www.qsl.net/w5dxp/travstnd.GIF

Note that for a standing wave current, the only thing
changing with length is magnitude. The flat phase line
of the standing wave current is completely useless for
making phase measurements.
--
73, Cecil http://www.qsl.net/w5dxp

Dave wrote:
thats the basic problem in this whole discussion. you are all talking about
the same thing, just using different notation and incomplete statements so
that none of you understands exactly what the others are trying to talk
about... when really you are all saying the same thing. its kind of like
after i graduated from college with an ee degree and my sister graduated
from an air force basic electronics course, she tried to ask me something
about currents in a transistor and i saw it all backwards... well of course
she was talking electron flow and i was talking hole flow. we both got the
same result but the notation was all different.

That's not true at all Dave. Most of us know that current is current.
It really only flows one direction at any instant of time. We can
indeed consider systems as having current that flows two directions at
one instant of time, but the results of that better agree with the
actual real current that flows only in one direction at any instant of
time or they are wrong.

Also, behavior of basic components cannot change. A two terminal device
like a loading coil cannot have differences in the current flowing
through it at each terminal without a third path. (I assume we all
know current is not an across vector and it does not "drop", the person
who started this thread just used poor wording.)

I think the basic problem is Cecil wants to used some definition of
current that does not allow models to be freely exchanged and does not
produce results that match real world systems. It always has to match.
We can't have different results unless someone has an error.

The only reason I'm skimming the posts here and making the occasional
comment is I hate to see people trying to understand how this stuff
works be confused. The real fuss is a couple people seem to think
standing waves or "missing antenna length" are the root cause of
current being different in the two terminal component called a loading
coil.

It really isn't an argument or debate as much as trying to help lurkers
understand how the system really works, and not let them fall into the
trap that the loading coil behavior is any different than any other
coil, the only possible reason for differences in current at each
terminal is stray capacitance allowing displacement currents to the
outside world, and that any phase differences in current at each coil
terminal are also tied to capacitance from the coil to the world around
the coil.

It's not correct to assume people are talking about the same result
different ways, because both Cecil and Yuri have huge flaws in their
conclusions. They both seem to want the inductor to behave in some very
unique way just because it is an antenna, and the reults they seem to
claim do not match actual measurements. Cecil dismisses real
measurements with frantic arm waving about reflected and forward
current and no one being able to measure current and phase because of
standing waves, and while I think Yuri would accept measurements he
won't accept them when made by others and won't make them himself.

This has gone on for perhaps three years now. It is really up to Cecil
and Yuri to let it go, since they are the ones who seem to disagree
with measurements and accepted theory.

73 Tom

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

Cecil,

I thought you denounced and denied this "concept" earlier today.

73,
Gene
W4SZ


Cecil Moore wrote:
If we had a coil installed
in that 30 degrees of the antenna instead of a wire, the same
concepts would apply.