Cecil,

I downloaded your EZNEC file, and I played around for a while with both
the original and several variations.

There were no surprises for the fundamental frequency case. When I
modeled a real bugcatcher coil, or at least as real as those on the GLA
web site, the current at the top of the coil was 85% to 90% of the base
current. I think it is more typical that a bugcatcher coil is at least 4
turns per inch rather than the 2 turns per inch in your example. I also
attempted to model the coil tested by Tom, W8JI, and reported earlier in
this thread. This coil pushes EZNEC both in terms of the number of
segments and the short length of the segments, but in any case it
appears that his coil when placed in your antenna model has higher
current at the top than you reported.

I ignored the harmonic examples. Who ever said that a coil would be a
lumped inductor when it is operated above its self resonant frequency?
Even your new guru from Mount Olympus, Dr. Teslacoil, does not discuss
such things.

In summary, the world of RF electrical phenomena is still intact. I
don't believe I have anything more to add, and I plan to back to sleep.

73,
Gene
W4SZ

Cecil Moore wrote:
Gene Fuller wrote:

1. I have looked at that figure, and I suspect many others have as
well. There is no information given about dimensions or any other
modeling conditions, so it is difficult to say anything more than,
"Yep, there's a bunch of lines and numbers on that figure."


Information has been added to the graphic at:

http://www.qsl.net/w5dxp/test316.GIF

The associated EZNEC file can be downloaded from:

http://www.qsl.net/w5dxp/test316.EZ

Gene Fuller wrote:
I think it is more typical that a bugcatcher coil is at least 4
turns per inch rather than the 2 turns per inch in your example.

I tried 4 turns per inch. EZNEC didn't like it.

I ignored the harmonic examples. Who ever said that a coil would be a
lumped inductor when it is operated above its self resonant frequency?

Whoever said that a coil would be a lumped inductor at 60%
of its self resonant frequency? Did you say that?

Used at 5.89 MHz, self-resonant at 9.75 MHz, phase-reversing at
11.78 MHz. Sounds a lot like a slow wave transmission line to me.
5.89 is 60% of the self-resonant frequency. Dr. Corum says that
the lumped-circuit fails above a 15% value. 60% is far above 15%.

In summary, the world of RF electrical phenomena is still intact.

Of course, and more than that, I took its side in the argument.

When I reported measuring no phase shift up and down a dipole,
Tom, W8JI, said my measurements were wrong. But EZNEC says
the same thing as I.
--
73, Cecil http://www.qsl.net/w5dxp

Gene Fuller wrote:
I ignored the harmonic examples. Who ever said that a coil would be a
lumped inductor when it is operated above its self resonant frequency?

Oh, I forgot to ask you a technical question, Gene. Given that
at 11.78 MHz, the current at the bottom of the coil is 0.17 amps
and the current at the top is 2.0 amps, how do you explain those
values if the current is flowing up through the coil? The details
are at the bottom of the following web page.
--
73, Cecil http://www.qsl.net/w5dxp/current.htm

Cecil Moore wrote:
Gene Fuller wrote:

I ignored the harmonic examples. Who ever said that a coil would be a
lumped inductor when it is operated above its self resonant frequency?


Oh, I forgot to ask you a technical question, Gene. Given that
at 11.78 MHz, the current at the bottom of the coil is 0.17 amps
and the current at the top is 2.0 amps, how do you explain those
values if the current is flowing up through the coil? The details
are at the bottom of the following web page.

Cecil,

Why is this an issue? Is there someone other than your strawman who has
a problem with this concept? I don't recall anyone ever questioning such
matters. Only in your imagination does anyone deny the existence of
distributed, non-lumped components.

If there really is such a person, it might be better to address your
query to him or to her.

73,
Gene
W4SZ

Gene Fuller wrote:

Cecil Moore wrote:
Oh, I forgot to ask you a technical question, Gene. Given that
at 11.78 MHz, the current at the bottom of the coil is 0.17 amps
and the current at the top is 2.0 amps, how do you explain those
values if the current is flowing up through the coil? The details
are at the bottom of the following web page.

I don't recall anyone ever questioning such matters.

You seem to be trying to have it both ways. 0.17 amps
is not equal to 2.0 amps. 0 degrees is not equal to
180 degrees. How are those values possible in a lumped
inductor?
--
73, Cecil http://www.qsl.net/w5dxp