On 4/20/2011 3:30 PM, David Gilbert wrote:
> The reason he posted
> his question was that modeling correctly indicated that it can sometimes
> be difficult to find the proper combination for a fan dipole that gives
> a good SWR on both bands without help from a tuner.
When I study W7EL's doc carefully, I see admonitions that it can be
QUITE tricky to get good modeling predictions for closely spaced wires.
One thing that helps is to make the modeling elements the same length.
When I model my fans I include the short fan-out lengths near the center
insulator, and also try to allow for insulation of the wire I use. Even
at that, I find that I must tweak them to length after I've had them in
the air.
73, Jim K9YC
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