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Cecil Moore[_2_] · April 3rd 09, 12:22 PM posted to rec.radio.amateur.antenna

wrote:
Did you ever try to model a resonator where the coil required is
actually longer than the insulator, so that the vertical part of the
resonator is actually inside the coil , ...

Never modeled it but have seen its effects during
75m mobile shootouts. One fellow had a hamstick
with the stinger bottom extending down into the
hamstick loading coil. It was a very lossy
condition which improved when he hack-sawed the
excess stinger off.

Do you have EZNEC? If so, I can modify a helical
loading coil to extend the stinger into the middle
of the coil and send the file to you.

Conductors within the loading coil field lower
the effective coil Q. However, I have had good
luck with a 1.25" fiberglass pipe running through
the center of the coil providing mechanical
support. Perhaps you could consider swapping your
insulator for a piece of fiberglass pipe or rod.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com