Gene Fuller wrote:
The question is what happens to the 75 degrees that was formerly
represented by the now-replaced wire. The coil may offer about 10 degrees.

I believe that Tom is stating that 75 is not equal to 10. Sounds like a
reasonable statement to me.

No argument from me. Obviously you didn't understand my previous
explanation that a resonant mobile antenna doesn't have to be 90
degrees long - something I explained weeks ago. Therefore, the coil
doesn't have to be 75 degrees. Please re-read my postings again below
until you understand what I said.

Think of all the possibilities that make (Vfor+Vref)/(Ifor+Iref)
purely resistive without any one of those terms being in phase with
any other of those terms. Then you will realize why that mobile
antenna is probably not 90 degrees long at all.

In my earlier posting, I gave values of phase that make the feedpoint
purely resistive without any one of those terms being in phase with
any other one of those terms.

BOTTOM LINE: Until you can prove that a mobile antenna is 90
degrees long, your argument is just another straw man. What is it
about my following previous statements that you don't understand?

W5DXP wrote:
You are confused. Some time ago, I explained why a mobile antenna
may not be 90 degrees long at all. Did you understand that posting?
All we can say is that (Vfor+Vref)/(Ifor+Iref) is purely resistive.
We don't know how many degrees the reflected wave has traveled in
its round trip because there are too many variables.

So please stop the diversions. I have always said that the delay
through a coil *IS WHAT IT IS* but it is NOT zero and it is not the
3 nS measured by W8JI for that 100 uH coil. It is also not the near-zero
phase shift measured by W7EL using standing wave current phase as the
reference. You, yourself, implied that is an invalid measurement when
you told us there is no phase information in standing wave phase.

Seems to me you are making my argument for me and that your real
argument is with the other side. Have you told W7EL that standing
wave current phase cannot be used to measure the delay through a
coil?
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:
Gene Fuller wrote:

The question is what happens to the 75 degrees that was formerly
represented by the now-replaced wire. The coil may offer about 10
degrees.


I believe that Tom is stating that 75 is not equal to 10. Sounds like
a reasonable statement to me.


No argument from me.


Cecil,

Does that end the thread? Or do you plan to keep expanding into unknown
territory where only your strawman lives?

73,
Gene
W4SZ

Gene Fuller wrote:
Does that end the thread?

Does agreeing that 75 is not equal to 10 end the thread?
Of course not. That posting *ASSUMED FOR THE SAKE OF
DISCUSSION* that EZNEC was reporting the actual delay
through the coil. I suspect it is not reporting the
actual delay because reflections are still present
inside the coil. The characteristic impedance changes
abruptly at the top of the coil so that would be no
surprise at all.

We know EZNEC blindly reports the net current that is
there. If we, as modelers, don't eliminate reflections,
EZNEC will not correctly report the traveling wave phase
shift. In our naivete', we didn't eliminate reflections.

75 degrees is probably not correct. 10 degrees is
probably not correct. Why do you want to quit before
the correct answer has been found?

************************************************** *
Here's a more valid procedure for determining the
delay through a coil. Changing nothing except the
number of turns, add turns until the coil is self-
resonant at the frequency of use. Frequency doesn't
change. Coil diameter doesn't change. Turns per inch
doesn't change. The *ONLY* thing that changes is the
length of the coil. At self-resonance, we *know* the
longer coil is 90 degrees long.
************************************************** *

Take that same 32 turn coil and keeping everything the
same, add turns to the coil until it is self-resonant.
We haven't changed the frequency, the diameter, or the
turns per inch. All we have done is add 37 turns to the
original 32 turn coil to make the self-resonant frequency
equal to 4 MHz with 69 turns. SINCE WE HAVEN'T CHANGED
THE FREQUENCY, WE KNOW THAT THE VELOCITY FACTOR OF THE
COIL HAS NOT CHANGED.

In the velocity factor equation, the only variables are
coil diameter, turns per inch, and wavelength. NONE OF
THOSE VARIABLES ARE CHANGED ABOVE.

So we know that 69 turns makes that coil stock self-resonant
at 4 MHz. That would make the phase shift through 32 turns
equal to 42 degrees, making our above 10 degree assumption
false. 42 degrees is probably fairly close to the actual value.
The velocity factor for that coil stock calculates out to
be 0.023 on 4 MHz.

The delay through a coil is what it is. The only valid side
to this argument are technical facts, valid measurements,
and valid modeling.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:


Here's a more valid procedure for determining the
delay through a coil.

Cecil,

So you think adding turns to a coil is a nice linear process that allows
you to then subdivide the resonance effects according the number of
turns in each subsection?

That's a good one. I almost injured myself laughing when I read it.

73,
Gene
W4SZ

Gene Fuller wrote:
So you think adding turns to a coil is a nice linear process that allows
you to then subdivide the resonance effects according the number of
turns in each subsection?

That appears to me to be the most valid measurement that we
can make of the delay through a coil. If you have a better
way, please present it.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:
Gene Fuller wrote:

So you think adding turns to a coil is a nice linear process that
allows you to then subdivide the resonance effects according the
number of turns in each subsection?


That appears to me to be the most valid measurement that we
can make of the delay through a coil. If you have a better
way, please present it.

Cecil,

C'mon, you know as well as anybody that inductance of a coil tends to
increase as n-squared. Yes, there are all kinds of special cases and
correction factors.

Adding turns and then pretending everything is nice and linear, thereby
allowing decomposition into subcomponents, is just plain silly.

73,
Gene
W4SZ

Gene Fuller wrote:
Cecil Moore wrote:

Gene Fuller wrote:
So you think adding turns to a coil is a nice linear process that
allows you to then subdivide the resonance effects according the
number of turns in each subsection?

That appears to me to be the most valid measurement that we
can make of the delay through a coil. If you have a better
way, please present it.

C'mon, you know as well as anybody that inductance of a coil tends to
increase as n-squared. Yes, there are all kinds of special cases and
correction factors.

Increasing the length of a coil or transmission line doesn't
change its velocity factor at a fixed frequency.

Adding turns and then pretending everything is nice and linear, thereby
allowing decomposition into subcomponents, is just plain silly.

Velocity factor is *nice* and linear, i.e. it is constant.

Please stop these diversions. I'm sure you are not that ignorant.
--
73, Cecil http://www.qsl.net/w5dxp