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Old January 3rd 09, 02:44 AM posted to rec.radio.amateur.antenna
Dave Dave is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 797
Default Does NEC-2 model wires as solid or hollow?


wrote in message
...
I've been using 4Nec2, a freeware antenna modeling program based on
NEC-2 (Numerical Electromagnetic Code). I'm wondering if anyone could
provide some insight as to just how it models current at the ends of
wires that are not connected to anything (a.k.a. "free ends" or "open
ends").

Does NEC-2 model "end caps" at free ends, which is equivalent to
assuming wires are solid, or does it just set the current equal to
zero at the free ends, which is equivalent to assuming wires are
hollow? Is it possible that it does both, but the specific model is
determined by the choice of computational kernel (extended vs.
standard)?

I've tried looking through some of the NEC-2 documentation, but I
can't find a definitive answer.

-Dave, K3WQ


the only one who would care about that is art who believes that current
flows back down the inside of the conductor. for the rest of us an end of a
wire is an end of a wire... the difference in capacitance from a filled end
to a hollow tube, unless the diameter of the hollow tube is a good fraction
of a wavelength should be negligible.