Thread: Vincent antenna
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Old November 29th 07, 11:42 PM posted to rec.radio.amateur.antenna
Cecil Moore[_2_] Cecil Moore[_2_] is offline
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Default Loading Coils; was : Vincent antenna

Jim Lux wrote:
While the model is certainly valid within
their stated limitations, the real question that arises is "why".


Because some people are claiming a 3 nS delay through
a 75m mobile loading coil. Corum's VF estimate says
it is more like 40 degrees rather than 4.5 degrees.

Furthermore, people HAVE made current measurements at the top and bottom
of a large tesla coil and found very small phase differences, indicating
that there is little or no deviation from a lumped model.


There is virtually no phase difference in standing-wave
current which is what was being measured. Standing-wave
current cannot be used to measure the delay through a
loading coil.

If the loading coil is located in a traveling-wave
environment, the delay through the coil is obvious
by the phase shift through the coil.
--
73, Cecil http://www.w5dxp.com