Current through coils
 

The phase shift along a coil, an inductor, considered as a
transmission line, obviously depends on what it is terminated with.
It much depends on frequency.

In the present context, the termination of the coil is the input
impedance of another transmission line consisting of a rod or length
of wire, or a capacitance hat, forming the remainder of the antenna.

To the participants to this discussion, just think about it. The
behaviour of the coil depends on the behaviour of the rest of the
system.

On the other hand, a coil has certain fixed parameters which are
independent of the rest of the system.

It is a good idea to restrict analysis to the resonant frequency of
the system. It assists with simpification and understanding of it.

Tonight, I've switched to Western Austalian dry white.
----
Reg.

Current through coils
 

wrote:

Cecil,
You have consistently disagreed with me when I said time delay through
an inductor with tight mutual coupling from turn-to-turn is somewhat
close to light speed over the physical length of the inductor, rather
than the time it takes current to wind its way around through the
copper.

I think I have figured out your misunderstanding here, Tom.
I *never* said the current winds its way around through the
copper. That was just another one of your strawmen that
I don't believe and have never believed. I have offered you
$100 if you can find where I ever said that. Would it make
any difference if I offered you $1000?

The effect of a velocity factor of 0.015 may seem to you
to be the same as "current winds its way around through
the copper" but I assure you, if you understood the wave
model of distributed network analysis, you would understand
why that is not the case.

I can fully understand why someone so emotionally
attached to the lumped-circuit model would assume
"current winding its way around through the copper"
but that is simply a misconception of yours.
Distributed networks are not nearly as simple-minded
as your lumped-circuits.

A helical coil structure with a VF of 0.015 *is what it
is*. Waves propagate at 0.015 the speed of light and
that's quite a delay through a relatively physically
short coil. If the coil is 6.5 inches long, as is my
75m bugcatcher coil, it occupies an electrical length
of 6.5"/.015 = 433" = 36 feet. The fact that it consumes
42 feet of wire is just a coincidence. The 6.5" coil
replaces aabout 36' of straight wire. From those facts,
you can calculate the number of degrees or percentage
of a wavelength.

Shirley, you understand that 1/4WL of a transmission
line with a 0.9 velocity factor is longer than 1/4WL
of line with a 0.66 velocity factor. That's why coax
stubs are shorter than 450 ohm ladder-line stubs. (I
feel like I'm doing a EE323 tutorial here).

What is it about a VF of 0.015 that you don't understand?
All it means is that RF through the coil is traveling
at 1/67 the speed of light. If you understand that
RF through RG-8 is traveling at 2/3 the speed of light,
why can't you understand "slow wave coils"?
--
73, Cecil http://www.qsl.net/w5dxp

Current through coils
 

Reg Edwards wrote:
To the participants to this discussion, just think about it. The
behaviour of the coil depends on the behaviour of the rest of the
system.

i.e. the behavior of the coil depends upon the reflected
energy in the system delivered back to the coil by other
elements in the system. That's basically why the lumped-
constant model fails.

Tonight, I've switched to Western Austalian dry white.

"Austalian"? You've got two choices, Reg. Sober up or
have another. I would have another. :-) But please note,
you have given up a lot of antioxidants from the reds.
--
73, Cecil http://www.qsl.net/w5dxp

Current through coils
 

John Popelish wrote:
Cecil Moore wrote:

. . . Do you think W7EL would
ever make a prediction based on the meager amount of
information provided? :-) A few years ago he provided some
information but kept changing parameters daily until I got
tired and withdrew my estimate. But it turned out in the
end that I was pretty close.

That's entirely untrue. The record is readily available via
groups.google.com for anyone interested in seeing what really happened.
The thread was "Current in antenna loading coils controversy (long)", in
November 2003.

. . .

Roy Lewallen, W7EL

Current through coils
 

Roy Lewallen wrote:
John Popelish wrote:

Cecil Moore wrote:
. . . Do you think W7EL would
ever make a prediction based on the meager amount of
information provided? :-) A few years ago he provided some
information but kept changing parameters daily until I got
tired and withdrew my estimate. But it turned out in the
end that I was pretty close.

The record is readily available via
groups.google.com for anyone interested in seeing what really happened.
The thread was "Current in antenna loading coils controversy (long)", in
November 2003.

Yes, indeed, it is, Roy. That's also my reference. And I have
learned a lot of the details underlying your myths since then.
--
73, Cecil http://www.qsl.net/w5dxp

Current through coils
 

Roy Lewallen wrote:
The record is readily available via
groups.google.com for anyone interested in seeing what really happened.
The thread was "Current in antenna loading coils controversy (long)", in
November 2003.

At that time in 2003, I was as naive as Galileo in front
of the court run by religious priests.

Any time you feel like apologizing for your questionable
behavior, all I ask is that you retract that single
"gobbledygook" statement that you made against my use of
the rules of the distributed-network model and laws of
reflection physics which are both a subset of Maxwell's
equations.
--
73, Cecil http://www.qsl.net/w5dxp

Current through coils
 

Cecil Moore wrote:

. . . Do you think W7EL would
ever make a prediction based on the meager amount of
information provided? :-) A few years ago he provided some
information but kept changing parameters daily until I got
tired and withdrew my estimate. But it turned out in the
end that I was pretty close.

W7EL wrote:

That's entirely untrue. The record is readily available via
groups.google.com for anyone interested in seeing what really happened.
The thread was "Current in antenna loading coils controversy (long)", in
November 2003.
Roy Lewallen, W7EL

Roy,

I'm also a victim of Cecil's twicted reality now.

I offered to make a measurement if he would even loosely predict
results and tell us in advance what they would mean. When he didn't
respond, I made the measurements anyway.

Time delay measurements of current at each terminal of a "bug-catcher
syle" loading coil are now at:

http://www.w8ji.com/inductor_current_time_delay.htm

Cecils is also writing what I said on QRZ. If anyone reads back through
his dozens and dozens of waffling posts, eventually they will find a
post where he acknowledges a phase delay I posed on QRZ was in voltage
across the source compared to voltage across a load resistance.

When I measured CURRENT at each end of the inductor (in that case the
inductor was a 1-1/4" long iron core 100uH choke), current had no
detectable amplitude or phase shift. Voltage from the generator was not
in phase with current because of the inductive reactance, but current
had the same relationship at each end of the choke.

Of course Cecil wrote that off as "measuring standing wave current that
is current that doesn't flow", and then suceeded in driving off
someone who was trying to straighten him out on that. All of that is
also in this thread for anyone to read.

There really isn't anything anyone can do to resolve any disagreement
with Cecil, because as soon as he frustrates them into giving up he
will rewrite everything that was said. My only hope is that people who
want to learn will look at the data and understand how an inductor
really works.

It would be comical to watch Cecil twist reality if it wasn't sad. The
sad part is there will be some people out there who will accept his
twisted logic. They won't take the time to read or ask hard questions.
The good part is my understanding of what goes on in a loading coil has
been improved, and I have more data for my web pages.

Fortunately the very high traffic volume into that site keeps it at the
top of search engines.

If you or anyone else finds anything that will clarify inductor
behavior, please let me know. I don't learn much from arguing with
Cecil, but I do learn from other contributors to this thread. I'd like
to thank everyone who has contributed. Even if it doesn't help
everyone, it helps some people.

73 Tom W8JI

Current through coils
 

On Sat, 11 Mar 2006 22:22:47 GMT, Cecil Moore wrote:
I was as naive as Galileo in front of the court run by religious priests.
Has Cecileo been dropping his balls off of the Tower of Pisa again?

Current through coils
 

Cecil Moore wrote:
. . . Do you think W7EL would
ever make a prediction based on the meager amount of
information provided? :-) A few years ago he provided some
information but kept changing parameters daily until I got
tired and withdrew my estimate. But it turned out in the
end that I was pretty close.
W7EL wrote:
That's entirely untrue. The record is readily available via
groups.google.com for anyone interested in seeing what really happened.
The thread was "Current in antenna loading coils controversy (long)", in
November 2003.
Roy Lewallen, W7EL
I'm also a victim of Cecil's twisted reality Roy.
I offered to make a measurement if Cecil would even loosely predict
results and tell everyone in advance what they would mean. When he
didn't
respond, I made the measurements anyway.
Time delay measurements of current at each terminal of a "bug-catcher
style" loading coil are now at:
http://www.w8ji.com/inductor_current_time_delay.htm
Cecil is also re-writing what I said on QRZ. If anyone reads back
through
his posts on this list, they will eventually find a post where he
acknowledges a phase measurement I posted on QRZ was in voltage
across the source compared to voltage across a load resistance.
My response was on Mar 9 2006 at 10:03 PM
When I measured CURRENT at each end of the inductor (in that case the
inductor was a 1-1/4" long iron core 100uH choke), current had no
detectable amplitude or phase shift. Voltage from the generator was not

in phase with current because of the inductive reactance, but current
had the same relationship at each end of the choke.
Of course Cecil wrote that off as "measuring standing wave current that

is current that doesn't flow", and then succeeded in driving off
someone who was trying to straighten him out on that. All of that is
also in this thread for anyone to read. The exact text is:
Cecil,
Good grief!!!!
I said several times that the standing wave does not move. I also said

the "wave" is not the same thing as the "current". The current is
nonzero even though the wave is stationary.
At this point it is obvious that you are just interested in causing a
fuss, and not the slightest bit interested in reaching any sort of
resolution of this item.
Bye.
73,
Gene
W4SZ
There really isn't anything anyone can do to resolve any disagreement
with Cecil, because as soon as he frustrates them into giving up he
will rewrite everything that was said. My only hope is that people who
want to learn will look at the data and understand how an inductor
really works.
It would be comical to watch Cecil twist reality if it wasn't sad. The
sad part is there will be some people out there who will accept his
twisted logic. They won't take the time to read or ask hard questions.
The good part is my understanding of what goes on in a loading coil has

been improved, and I have more data for my web pages.
Fortunately the very high traffic volume into that site keeps it at the

top of search engines.
If you or anyone else finds anything that will clarify inductor
behavior, please let me know. I don't learn much from arguing with
Cecil, but I do learn from other contributors to this thread. I'd like
to thank everyone who has contributed. Even if it doesn't help
everyone, it helps some people.
73 Tom W8JI

Current through coils
 

Cecil Moore wrote:
Roy Lewallen wrote:

The record is readily available via groups.google.com for anyone
interested in seeing what really happened. The thread was "Current in
antenna loading coils controversy (long)", in November 2003.


At that time in 2003, I was as naive as Galileo in front
of the court run by religious priests.

Any time you feel like apologizing for your questionable
behavior, all I ask is that you retract that single
"gobbledygook" statement that you made against my use of
the rules of the distributed-network model and laws of
reflection physics which are both a subset of Maxwell's
equations.

Cecil, have you ever read the book _Don Quixote_, by Cervantes?
There's a character in there you remind me of.
73,
Tom Donaly, KA6RUH