On Tue, 04 Dec 2007 02:16:36 GMT, Gene Fuller
wrote:

The calculator is at

http://hamwaves.com/antennas/inductance.html

I believe that Owen first mentioned that website, but I could be wrong.

I am looking at the calculation for beta, the axial propagation factor.
It appears to be unchanged for any length of coil from very short to
much longer than a quarter-wave resonant length.

Hi Gene,

On visiting the site, I plugged in Tom's numbers, specifically:
D = 50mm
N = 100
l = 254mm
d = 1mm

ß varied by frequency in a non-linear fashion, roughly x10 per decade
shift up in frequency from 40kHz.

What was strange was how "Parallel stray capacitance" wandered the map
to become inductive (-1 pF) at 40 MHz (and become a non-number above).

73's
Richard Clark, KB7QHC