Re: Quarter Wavelength Frequency

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ed Phillips" <evp-at-pacbell-dot-net> 

 >   L/D   length of wire/lambda     velocity_factor
  >   0.5   0.228                      0.912
  >   1.0   0.298                      1.192
  >   1.5   0.343                      1.372
  >   2.0   0.374                      1.496
  >   3.0   0.413                      1.652
  >   4.0   0.435                      1.740
  >   5.0   0.449                      1.796
  >   7.0   0.466                      1.864
  >   10    0.478                      1.912
  >   100   0.49998                    1.99992
  >   1000  0.50000                    2.00000

where L/D = axial_length/diameter = h/d, lambda is an abbreviation
for 'free space wavelength'.

Ed's figures are based on Ldc (via Lundin) and Medhurst C from
a series."

	The last sentence turns out to be wrong.  On reading a listing I
realized I had used Wheeler's simplest approximation instead of Lundin's
much more exact method, but for the range of L/D above the difference is
less than  a percent so makes no significant difference in the results.
The main error is in estimating Cd anyway.  Of course the velocity
factor approaching 2.000000000 is an artifact of the program, not a
fundamental law of nature.

Ed