Cecil Moore wrote:
"Gene Fuller" wrote in message:

Where is the transition in Vf from the ~1 for zero
turns to ~0.02 for a resonant coil?


Take the VF=0.02 resonant coil and divide it into two equal
coils. Do you really expect the two coils to have VFs of 1.0
while their end-to-end combination results in a VF of
0.02? Please quote the laws of physics that allows such
to happen.
--
73, Cecil, W5DXP


Cecil,

What is the mystery? Have you never seen a response curve for a resonant
condition? It is not exactly linear.

You are the expert on Vf. You assert without proof that a half-length
coil has the same Vf as the full-length resonant coil. OK, even if I
accepted that supposition, what happens at a quarter-length or at a
tenth-length? I am simply asking how the function changes between the
"known" limits of 1.0 and 0.02. You have repeatedly ducked any sort of
answer.

73,
Gene
W4SZ

"Gene Fuller" wrote:
I am simply asking how the function changes between the
"known" limits of 1.0 and 0.02. You have repeatedly ducked any sort of
answer.

On the contrary, I just posted the answer for the third time. The
Y-axis answers your question. Hold the diameter/lamda ratio
constant and vary the turns/lamda to answer your question.
Do I have to plot zero turns/lamda for you?
--
73, Cecil, W5DXP

Gene Fuller wrote:
You are the expert on Vf. You assert without proof that a half-length
coil has the same Vf as the full-length resonant coil. OK, even if I
accepted that supposition, what happens at a quarter-length or at a
tenth-length? I am simply asking how the function changes between the
"known" limits of 1.0 and 0.02. You have repeatedly ducked any sort of
answer.

Seems Richard Clark has proven that it doesn't change between
the "known" limits of 1.0 and 0.02. Where did those "known"
limits come from anyway?

For a single turn coil, seems the VF would roughly be the pitch
divided by the circumference, something that would equal 1.0 only
when the pitch and circumference were equal.

For the 4 TPI, 6" diameter coil, the VF formula yields 0.02.

The pitch divided by the circumference yields 0.013.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil,

Since you have fallen back to the old "round and round the helix" model
there is little hope for agreement. It is interesting, however, that
even the Corum model for Vf at resonance is not as slow as the purely
geometric model. Must be those standing waves again.

73,
Gene
W4SZ

Cecil Moore wrote:
Gene Fuller wrote:

You are the expert on Vf. You assert without proof that a half-length
coil has the same Vf as the full-length resonant coil. OK, even if I
accepted that supposition, what happens at a quarter-length or at a
tenth-length? I am simply asking how the function changes between the
"known" limits of 1.0 and 0.02. You have repeatedly ducked any sort
of answer.


Seems Richard Clark has proven that it doesn't change between
the "known" limits of 1.0 and 0.02. Where did those "known"
limits come from anyway?

For a single turn coil, seems the VF would roughly be the pitch
divided by the circumference, something that would equal 1.0 only
when the pitch and circumference were equal.

For the 4 TPI, 6" diameter coil, the VF formula yields 0.02.

The pitch divided by the circumference yields 0.013.

"Gene Fuller" wrote:

W5DXP wrote:
For the 4 TPI, 6" diameter coil, the VF formula yields 0.02.

The pitch divided by the circumference yields 0.013.

Since you have fallen back to the old "round and round the helix" model
there is little hope for agreement. It is interesting, however, that
even the Corum model for Vf at resonance is not as slow as the purely
geometric model. Must be those standing waves again.

Anyone who says the current goes "round and round the helix"
is wrong. Anyone who says the current goes like a "short circuit
through the coil is wrong."

There is NO rail "round and round the helix'! There is NO rail
"short circuit through the coil"! There is, as usual, something in
between the two rails. Looking at Fig. 1 in Dr. Corum's IEEE paper:

For a diameter/wavelength ratio of 10^-3

If the coil is1000 turns/wavelength, the VF is 0.8 which is closer
to a "short circuit through the coil" than it is to "round and round
the helix".

If the coil is 5000 turns/wavelength, the VF is 0.18 which is
closer to "round and round the helix" than it is to a "short
circuit through the coil".

The field coupling between the coils is responsible for the VF
not being as slow as the purely geometric model but there is
a practical physical limit to the number of coils that are being
coupled.

Coils are a combination of primary and secondary characteristics.
All the primary characteristics need to be taken into account. Some
of the secondary characteristics can be omitted under certain
conditions.
--
73, Cecil, W5DXP