Current across the antenna loading coil - from scratch
 

John Popelish wrote:
If you want to deny the existence
of forward and reflected current, be my guest.

I deny it. There is only current at a point, just as there is only
water jiggling around under a wave on the ocean.

Well, that means denial of the distributed network model.
I've been waiting for that to happen. There's no point
continuing an argument with someone who denies one of
the cornerstones of EM wave theory.

The distributed network model is accepted as a superset
of the lumped circuit model and works when the lumped
circuit model fails.

The fact remains that standing wave current phase cannot
be used to measure phase delay through a wire or through
a coil. There is no phase information in standing wave
current phase.
--
73, Cecil http://www.qsl.net/w5dxp

Current across the antenna loading coil - from scratch
 

John Popelish wrote:
As far as the center conductor is concerned, the shield is the entire
universe.

My point exactly! There is no third path to the outside
world but the standing waves do exist inside the coax
without it.
--
73, Cecil http://www.qsl.net/w5dxp

Current across the antenna loading coil - from scratch
 

On Sun, 09 Apr 2006 02:55:44 GMT, Cecil Moore
wrote:

Please tell us about the position and velocity of each
charge carrier, Richard.

-no-

Current across the antenna loading coil - from scratch
 

On Sun, 09 Apr 2006 03:31:59 GMT, Cecil Moore
wrote:

There's no point continuing an argument

The triumph of hope over experience.

..... haven't we been here before? And then to continue on to the
triumph of experience over hope?

Stay tuned for another episode of "Disparate Old Housewives"

Current across the antenna loading coil - from scratch
 

Cecil Moore wrote:
John Popelish wrote:

As far as the center conductor is concerned, the shield is the entire
universe.


My point exactly! There is no third path to the outside
world but the standing waves do exist inside the coax
without it.

But from the concept of a standing wave producing a current
distribution along the center conductor, the shield performs the
function of ground. One current path is along the center conductor
(in one of two directions) and the other current path is through the
dielectric to the shield, in proportion to the rate of change of
voltage at any point on the center conductor.

If you eliminate the shield and have a single wire carrying a standing
wave over a distant ground, the capacitance per foot drops (raising
the characteristic impedance of the transmission line, and losing
energy to EM waves, but the displacement current is still there in
proportion to the capacitance per foot and the rate of charge of
voltage. There is nothing inherently different. Only the loss and
ratio of L/C per foot changes.

Current across the antenna loading coil - from scratch
 

Richard Clark wrote:
Cecil Moore wrote:
There's no point continuing an argument

The triumph of hope over experience.

When one rejects the distributed network model,
one must also reject Maxwell's equations. That
seems like a religious act to me, not a technical
choice.
--
73, Cecil http://www.qsl.net/w5dxp

Current across the antenna loading coil - from scratch
 

John Popelish wrote:
But from the concept of a standing wave producing a current distribution
along the center conductor, the shield performs the function of ground.

But that is irrelevant. The relevant fact is that there is NO
third path to ground yet the standing waves exist anyway.

That seems to indicate that the displacement current path
to outside world ground is a secondary consideration compared
to the superposing of the forward and reflected waves.

If you are prepared to reject the distributed network model,
are you also prepared to reject Maxwell's equations?

Please note that rejection of the distributed network
model leaves you with only a model known to fail under
certain conditions.

In any case, you haven't explained how the unchanging
phase in a standing wave current can be used to measure
phase shift through a wire or a coil. EZNEC says it
is not a valid approach at:

http://www.qsl.net/w5dxp/travstnd.GIF
--
73, Cecil http://www.qsl.net/w5dxp

Current across the antenna loading coil - from scratch
 

John Popelish wrote:
Cecil Moore wrote:
If you want to deny the existence
of forward and reflected current, be my guest.

I deny it. There is only current at a point, just as there is only
water jiggling around under a wave on the ocean.

There is only water juggling under two or more waves in the
ocean. Anyone who has stood on the beach has observed ocean
waves moving in opposite directions.

Your assertion is easy to disprove. In the following example,
the two sources have identical outputs and are phase locked.
They are each equipped with circulators and 50 ohm loads.

Source1---------------50 ohm coax------------------Source2

There is current flowing from Source1 heating up Source2's
load resistor to the tune of I1^2*R. There is current
flowing from Source2 heating up Source1's load resistor
to the tune of I2^2*R. Your denial seems to be a denial
of reality and more of a religious gut feeling than anything
else.

If you disconnect Source2 completely in the example above
the conditions will be the same except Source1 will be
dissipating its own power after a round trip to the open
end and back by the energy waves.

Incidentally, in the double source example above, which
direction is the standing wave current flowing? How could
its unchanging phase be used to measure the electrical
length of the coax?
--
73, Cecil http://www.qsl.net/w5dxp

Current across the antenna loading coil - from scratch
 

Cecil Moore wrote:
John Popelish wrote:

If you want to deny the existence
of forward and reflected current, be my guest.


I deny it. There is only current at a point, just as there is only
water jiggling around under a wave on the ocean.


Well, that means denial of the distributed network model.

Please don't be silly. Distributed networks have points. An infinite
number of them. Calculus is used to smoothly move through this
infinity of points. But at any particular point, current is defined
as the rate of movement of charge past that point.

I've been waiting for that to happen. There's no point
continuing an argument with someone who denies one of
the cornerstones of EM wave theory.

So you deny that there are any points (where voltage can be defined or
that charge passes) in all distributed networks?
How strange.

The distributed network model is accepted as a superset
of the lumped circuit model and works when the lumped
circuit model fails.

Yes. And distributed networks are made of a continuum of points.

The fact remains that standing wave current phase cannot
be used to measure phase delay through a wire or through
a coil. There is no phase information in standing wave
current phase.

Yes. That fact remains.
It is a non sequitur in the above discussion, however.

That the standing wave current cycle has the same phase along a half
wavelength of conductor has nothing to do with the current through
that conductor having a point definition (the x in the standing wave
function you keep displaying). And at any point the current is AC,
spending half of the time going one way, and half of the time going
the other way (the positive and negative parts of the cycle in time,
defined by cos(kx)*cos(wt), once you pick and x.

Current across the antenna loading coil - from scratch
 

Cecil Moore wrote:
John Popelish wrote:

But from the concept of a standing wave producing a current
distribution along the center conductor, the shield performs the
function of ground.


But that is irrelevant. The relevant fact is that there is NO
third path to ground yet the standing waves exist anyway.

That seems to indicate that the displacement current path
to outside world ground is a secondary consideration compared
to the superposing of the forward and reflected waves.

To the center conductor, carrying the standing wave, the shield is the
outside world. If there is no shield, the outside world is the
outside world, as far as displacement current goes. Do you imagine
this current changes in some way other than magnitude and wave
velocity when you wrap a shield around a wire carrying a standing wave?

If you are prepared to reject the distributed network model,
are you also prepared to reject Maxwell's equations?

I am prepared to do no such thing. I am explaining distributed
network theory to you.

Please note that rejection of the distributed network
model leaves you with only a model known to fail under
certain conditions.

Just because I talk about current and voltage at points does not mean
I am limited to lumped (idealized) networks. Distributed networks are
made of points, too.

In any case, you haven't explained how the unchanging
phase in a standing wave current can be used to measure
phase shift through a wire or a coil. EZNEC says it
is not a valid approach at:

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

And I have agreed with that. Why do you keep bringing it up?

You are sounding like someone with an obsession. Perhaps you need
some down time to let this rattle around in your subconscious.

Sometime I'll tell you the dream I had, in which I was a capacitor.
Woke up in a cold sweat with an understanding of something fundamental
about capacitors I had been stuck on.