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  #931   Report Post  
Old April 3rd 06, 07:10 PM posted to rec.radio.amateur.antenna
Richard Clark
 
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Default Current through coils

On Mon, 3 Apr 2006 09:35:16 -0400, "Yuri Blanarovich"
wrote:

So far, it looks to me that this exercise is worthwhile if we can improve
the accuracy of modeling and our understanding of the phenomena.


Hi Yuri,

If you can't give me a metric of what the accurcy IS, then you cannot
say you've improved or worsened it at the end of the process, can you?

Like I said, "What's all the fuss over? What's to be
proven? and How do we know when it has BEEN proven?"

You aren't providing any forward momentum.

73's
Richard Clark, KB7QHC
  #932   Report Post  
Old April 3rd 06, 07:37 PM posted to rec.radio.amateur.antenna
K7ITM
 
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Thanks, Tom.

In fact, let's get back to something very basic about antennas.

Acceleration of CHARGE results in electromagnetic RADIATION.

RADIATION impinging on a receiving antenna (and on anything else that
freely transports charge) causes acceleration of CHARGE within that
antenna.

So when we are talking about antennas, it is very appropriate to be
talking about charge, and exactly what happens to it to move it around
and to accelerate it as a function of time, everywhere in the
structure.

A voltage applied to the feedpoint terminals of an antenna causes
CHARGE to be put into motion. Accumulation of CHARGE along the
conductors--the distribution of charge as a function of time and
space--in turn results in electric fields in the vicinity of the
antenna. Motion of charge results in magnetic fields in the vicinity
of the antenna. Capacitance and inductance are manifestations of the
electric and magnetic fields, respectively. Taken as a whole, the
motion of charge and the resulting electric and magnetic fields give
rise to waves: the waves, too, are manifestations of the electric and
magnetic fields. ALL of these are consistent with each other, and to a
very good approximation agree with the descriptions worked out by
Faraday, Gauss, Maxwell and all many years ago. (We don't need quantum
theory to be talking about performance of an 80 meter mobile antenna!)

Please, let's keep it straight that the motion of charge is FUNDAMENTAL
to all this analysis, and everything else will fall out very nicely
from an accurate accounting of the motion of charge within the system.
It is NOT irrelevant at all; it is at the very heart of the operation
of ALL antenna systems.

Cheers,
Tom

  #933   Report Post  
Old April 3rd 06, 07:43 PM posted to rec.radio.amateur.antenna
Cecil Moore
 
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K7ITM wrote:
"Cyclical variation in charge (contained
within a volume)" means that on average the charge stays constant, but
it does not mean that it's constant over some arbitratily short but
finite length of time.


The current reported by EZNEC is RMS current, Tom. What happens
within a cycle is irrelevant to this discussion.

We are not and never have been discussing variations within a
cycle. There's just no point. We have been discussing RMS values
of currents. Your attempt to again divert the issue is noted. We
are talking about net charge spread out over many steady-state
cycles. That net charge is always zero no matter what the RMS
value of the standing wave current at the ends of the coil.

Without the capacitance, without the ability to store charge, a
transmission line, an antenna wire, a loading coil, all of them--would
not have the ability to cause delay. Freespace, without a non-zero
permittivity (capacitance), would allow infinite speed of light. But
all these things DO have capacitance, and they DO have
speed-of-propagation at the speed of light or slower.


Please tell us something we don't already know.

It has become apparent that the discussion is not about coils at
all. It is about the nature of standing waves whether existing
in a transmission line, a standing wave antenna wire, or a coil.
--
73, Cecil http://www.qsl.net/w5dxp
  #934   Report Post  
Old April 3rd 06, 08:18 PM posted to rec.radio.amateur.antenna
Cecil Moore
 
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Tom Donaly wrote:
Cecil, since you always leave the phase information out of
your version of the solution of the wave equation, I don't
think Diogenes is going to be knocking on your door anytime soon,
either.


I'm not leaving phase out, Tom, Mother Nature leaves phase out
of the standing wave equation. What is it about Gene Fuller's
posting that you don't understand?

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.

--
73, Cecil http://www.qsl.net/w5dxp
  #935   Report Post  
Old April 3rd 06, 08:19 PM posted to rec.radio.amateur.antenna
Cecil Moore
 
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Default Current through coils

wrote:
Wow! First he uses TWT's.
....and then he shifts it to traps!!!
Next heating elemennts or slinkys I suppose.


Wow, consider the technical content of your posting and wonder
why there is none.
--
73, Cecil
http://www.qsl.net/w5dxp


  #936   Report Post  
Old April 3rd 06, 08:22 PM posted to rec.radio.amateur.antenna
Cecil Moore
 
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Default Current through coils

Tom Donaly wrote:
There is no "net" charge storage on a capacitor in an AC
environment, either, Cecil, but you can still get current
to go through it.


True, but completely irrelevant to the present discussion
so more than likely another straw man.

Once more, the subject is the RMS standing wave envelope
reported by EZNEC. Brownian motion of individual electrons
is completely irrelevant.
--
73, Cecil http://www.qsl.net/w5dxp
  #937   Report Post  
Old April 3rd 06, 08:45 PM posted to rec.radio.amateur.antenna
K7ITM
 
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Hey, Cecil, have you read "Freakonomics"? (Yes, it's relevant to the
discussion.)

  #938   Report Post  
Old April 3rd 06, 09:44 PM posted to rec.radio.amateur.antenna
Richard Harrison
 
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Tom, K7ITM wrote:
"A voltage applied to the feedpoint terminals of an antenna causes
CHARGE to be put in motion. Accumulation of CHARGE along the
conductors--the distribution of charge as a function of time and
space--in turn results in electric fields in the vicinity of the
antenna."

Agreed that current is charge in motion. Accumulation of charge,
however, is a job for an accumulator, another name for a storage
battery. These have little to do with the possibility of an antenna coil
having currents through the coil from opposite directions creating
unequal totals at the ends of the coil.

I don`t know if this Tom is picking a fight to gain attention before
going to Dayton but his postings have the right fragarance.

Best regards, Richard Harrison, KB5WZI

  #939   Report Post  
Old April 4th 06, 12:30 AM posted to rec.radio.amateur.antenna
Tom Donaly
 
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Cecil Moore wrote:

Tom Donaly wrote:

Cecil, since you always leave the phase information out of
your version of the solution of the wave equation, I don't
think Diogenes is going to be knocking on your door anytime soon,
either.



I'm not leaving phase out, Tom, Mother Nature leaves phase out
of the standing wave equation. What is it about Gene Fuller's
posting that you don't understand?

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.


Well, I guess it's o.k. for you to believe that when a wave travels down
a transmission line it always ends up in phase with where it started.
That simplifies things for your theory. It doesn't make for a very
good transmission line, though.
73,
Tom Donaly, KA6RUH
  #940   Report Post  
Old April 4th 06, 12:33 AM posted to rec.radio.amateur.antenna
Tom Donaly
 
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Richard Harrison wrote:

Tom, K7ITM wrote:
"A voltage applied to the feedpoint terminals of an antenna causes
CHARGE to be put in motion. Accumulation of CHARGE along the
conductors--the distribution of charge as a function of time and
space--in turn results in electric fields in the vicinity of the
antenna."

Agreed that current is charge in motion. Accumulation of charge,
however, is a job for an accumulator, another name for a storage
battery. These have little to do with the possibility of an antenna coil
having currents through the coil from opposite directions creating
unequal totals at the ends of the coil.

I don`t know if this Tom is picking a fight to gain attention before
going to Dayton but his postings have the right fragarance.

Best regards, Richard Harrison, KB5WZI


If you don't understand the post, I guess a cheap shot is
better than no shot at all.
73,
Tom Donaly, KA6RUH
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