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