Cecil Moore wrote:
Gene Fuller wrote:

Cecil Moore wrote:
A 75m bugcatcher coil is self resonant at 6.6 MHz. That's
near 4 MHz. Where is all your irrationality coming from?

The exact quote from your message on April 11, at 9:57 am is copied
below. I don't see anything about a bugcatcher coil.


The coil being discussed is a bugcatcher coil modeled in EZNEC.

Since the Corum paper highlighted the limitation for applicability of
the magic formula it is possible he thought that the limitation might
be important.


The limitation that Dr. Corum highlighted was the failure of the
lumped circuit model when the coil is self-resonant. He says that
when we are within 17% of self-resonance, the lumped circuit model
fails. Have you anything besides faith to prove that your model
is valid within 60% of self-resonance?

Please describe the physics behind a radical change in velocity
factor (at the same frequency) when a coil is cut in half.

Cecil,

You have really lost it. I gave you the exact quote, and you then
proceed to talk about something else.

It appears you did not really read and understand the Corum paper
either. The portion I referred to you had nothing to say about lumped
circuits or distributed circuits. It was merely a step in the
mathematical analysis that leads to the magic formula for Vf. If you
ignore the important limitations on the math analysis it is likely that
any conclusions drawn will be incorrect.

So let's throw the topic back to you. A straight wire has a Vf near 1. A
resonant coil has a Vf of 0.01 or 0.02. So where and how does the Vf
transition occur? For a coil of one turn? For a coil with a length of
15% of the resonant length? At some other coil length? Is the Vf
transition abrupt or smooth?

You seem to understand everything about coil Vf, so these should be easy
questions for you.

73,
Gene
W4SZ