Gene Fuller wrote:
As for the Corum paper, would you be so kind as to point out the page
where it is written:

The velocity factor equation is appropriate for quarterwave resonance
*and* any other length at the same frequency.

I already told you - same page, Fig. 1 where that VF equation is
plotted. There is absolutely no reference to coil length in Fig. 1.
The only independent variables are the diameter/wavelength ratio
and the turns/wavelength ratio. For any length coil with the above
fixed parameters, including frequency, the VF is constant within
10%.

I found the section that says the formula is appropriate at resonance,
and I must have missed the part that says the formula works for any
length as long as the frequency is maintained.

"We have found that this expression gives acceptable results (errors
less than 10%) for most practical applications that involve wave
propagation on helical resonators ..." Absolutely no mention of
14WL self-resonance.

You still have not explained at what point the transition from Vf ~ 1 to
Vf 0.02 occurs.

It is explained perfectly in Fig. 1 where the VF scale goes from
0.0 to 1.0. Come over to my house for a beer and I will teach you
how to read that graph.

Exactly as would be expected, holding the diameter/wavelength ratio
constant, as the helical is wound tighter and tighter, the VF decreases.
--
73, Cecil http://www.qsl.net/w5dxp