Topband: Folded Unipole vs Series Fed Vertical

[John Kaufmann]

At 08:33 AM 12/15/99 -0500, Tom Rauch wrote:

>I've found systems that behave like that Bill. They almost max out 
>at 30 or 40 radials.
>
>If you look at LB&E's paper...if the radials are only .234 wl long the 
>curve is almost totally flat at 50 radials and in the 90% eff range.

As I recall, the Lewis, Brown, & Epstein paper did show a small additional
gain (something like 1 dB, maybe a bit less) by going to 120 radials but
only when those radials were on the order of 0.4 wavelengths long.  In the
NAB paper, the radials were about 0.25 wavelengths, in which case more than
30 radials would not be expected to bring much improvement.  To see the
benefit of 120 radials, those radials would have to be made longer.  In
short, a LOT more radial wire (and real estate for the radials) is required
for a small gain.

73, John W1FV



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