NEC-LIST: simulation of Q

Greetings:

Several years ago we had took detailed measurements of the impedance of a
trailing wire on a C-130. We stepped the wire length in fairly small
increments and then swept the impedance measurement frequency about the
resonant length for one-quarter wavelength and for thre-quarters
wavelength. This process was repeated for frequencies from 0.5 MHz to 30
MHz. I had accurate measurements of the wire resistance vs frequency.
When I tried to simulate this using NEC-4, the Q obtained was much too
high. The aircraft model was a grid of one-inch diameter wires. Modifying
the conductivity of the trailing wire got me no closer to the measured Q.
However, I found that modifying the conductivity of the aircraft wires
showed promise, and I ended up using the measured resistivity for the
trailing wire and using the conductivity of zinc for the aircraft skeleton,
0.166E7 S/m.

Smilin' Chuck

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