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Old March 10th 06, 02:08 PM posted to rec.radio.amateur.antenna
 
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Default Current through coils


Cecil Moore wrote:

The generator sees a reactive load. When the generator sees a reactive
load, current and voltage are no longer in step. This is true all
through the system from source to load.


I didn't ask or say anything about voltage. The fact that you
refuse to answer my technical questions speaks volumes.


The fact you can't understand simple direct answers does the same. You
asked how what I measured could happen, I answered. You either are
choosing to ignore the answer becuase you don't like it, or you don't
understand it.

Please define "compact" in terms of the number of degrees
of phase shift measured using a traveling wave.


Phase shift in what Cecil?


The measured phase shift is in a traveling wave through a 75m
bugcatcher coil. How long does it take the traveling wave current
to flow from one end of the coil to the other? Your lumped-circuit
model presupposes instantaneous current flow for traveling waves.
Let's measure the current delay in a traveling wave to see
if your model is correct. If it is not correct, it is useless.


When Roy measured current (and I did the same) using inductive coupling
in a current trasformer, a method that requires a time-varying current
to excite the secondary, you dismissed Roy's measurements with some odd
response about him measuring current that doesn't flow.

I already measured the phase of current, and it is nearly zero degrees.
It seems obvious to me that when someone gives you and answer you don't
like, you either personally attack that persona and call them a liar or
you make up some lame excuse like "you measured current that doesn't
flow".

I don't know what others think, but it is starting to look to me like
you either don't understand the basics of measurements or you are just
unwilling to learn.


You cannot even begin to understand the problem if you don't
know that basic phase shift. I'm willing to bet that my 75m
bugcatcher coil has at least a 40 nanosecond delay on 4 MHz
which is a 60 degree current phase shift.


I can measure that. My network analyzer measures time delays. The
problem I see is if I take time from my busy schedule and measure it,
you will either call me a liar or say I measured current that doesn't
flow.

Before measuring anything specific I'm going to warn you that I've
measured group delays many times before, and the group delay in an
inductor is significantly less than the group delay in a transmission
line of the same conductor length. I know that from past experience.

But if you promise to control yourself and not dismiss a measurement
with personal attacks or insults, and promise to not do an about-face
like you did with Roy and say "you really didn't measure current that
moves with your thing that only measures changing current", I will do
that.

I really wish some of your ideas were correct. If they were correct, I
would not have thousands of feet of coaxial cables coiled under my
bench. I would not be forcing customers to cut long delay lines when
their equipment could just use a simple wound up piece of enameled
wire.

If that measured delay is in the ballpark of 40 nanoseconds
or more, it proves that your lumped-circuit model has failed
and your invalid proof is presupposed in the invalid model.


The only potential problem is your reaction to measurements.

You keep trying to define the "inductor" in terms of degrees related to
standing waves ...


Not true, Tom, and just shows how confused you are about
what I have said. For the Nth time: The phase of the standing
wave current doesn't change up and down the entire length
of a 1/2WL thin dipole. Why would anyone expect it to change
at the ends of a loading coil? As far as I am concerned we
can drop any discussion of standing wave current phase. It is
meaningless. The phase that Roy measured was standing wave
phase. It was already known and is completely irrelevant. I
asked Roy to measure the traveling wave phase shift. He didn't.


Does ANYONE on this newsgroup understand Cecil? I need help here.


I have done it and told you how, you ignore it. Roy has done it and
told you how, you ignore it.


You guys are measuring standing wave current that doesn't
flow and doesn't change phase. Your measurements are
completely meaningless and your flawed model has you
hoodwinked.


What a silly statement. We are measuring a time-varying current that
doesn't flow or change!

The only way to get confused on that is if someone doesn't understand
behavior of the basic component, gets in over his head and confuses
himself trying to use a tool that doesn't work, and then lashes out at
others and refuses to listen.


That's an exact description of you and your lumped circuit
analysis in a standing wave environment. Do you disagree with
Walter Maxwell?

Walt wrote:
"If an inductance is in series with a line that has reflections,
the current will NOT be the same at both ends of the inductor."

"Consequently, circuit analysis will not work when both forward
and reflected currents are present in a lumped circuit."


Yes, if he wrote what you quoted and you didn't lift something out of
context I totally disagree with him.

The component is not the problem, Tom. The problem seems to be
your feigning of total ignorance of the laws of reflection
physics in order to avoid discussing the real problem.


I don't think most qualified experienced people would think I am the
ignorant one.

There you go again! Back to traveling and standing waves.


Yes, you are never going to understand what I am saying about
standing-wave antennas until you discuss traveling and standing
waves on the standing-wave antenna. Your lumped-circuit model
is known to fail in the presence of standing waves.


Nonsense.

There you go again, back to the lowest form of debate. If you

can't
understand something or get trapped, just call the other guy a liar.


No, it's a lot simpler than that. When you lie about something
I said, I call you a liar.


There you go again. Do you have any idea how statements like that make
you look to others?

You very clearly said current in each terminal of the inductor has a
different phase shift several times in your posts.


One more time. The standing wave current does NOT change phase
at the ends of the coil. The standing wave current essentially
does not change phase unless a dipole is longer than 1/2WL.
The phase of the standing wave current is totally irrelevant.


The forward traveling-wave current experiences a delay through
the coil. The reflected traveling-wave current experiences a
delay through the coil. This delay can be measured on the bench.
If the delay is not negligible, your lumped-circuit model is
useless because it presupposes a delay of zero.

I can't understand what you are saying or what your point is, ...


Please don't insult my intelligence or yours. Every one of us
performed those experiments on the bench in college. Exactly
what is it about bench measuring the RF current delay through
a coil that you don't understand?


I understand it fine. I don't think the problem is on my end. If it is,
someone besides you will chime in and tell me. I'm afraid I don't trust
your opinions very much.

Maybe someone else can help me with your last statement.


Do you even know what a standing wave current loop is?


Do you?

Maybe someone else on this group can explain or understand what you are
trying to say.


You must have missed EE203. :-) What is it about a continuous
exchange of energy between the E-field and H-field at a fixed
point on an antenna wire that you don't understand? That's
just a characteristic of standing waves. Roy has used the
same argument in the past to try to prove that reflected
energy doesn't flow. But's it's the standing wave energy
that doesn't flow.


Are you confusing energy and current? Or are you just joking again?

73 Tom