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Old April 29th 06, 08:31 PM posted to rec.radio.amateur.antenna
Roy Lewallen
 
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Default J_Pole Trials and Tribulations

wrote:
I happen to like them as they can be made from common materials with
excellent ruggedness. As to the other claims of fantastic gain and
all, it's bogus. It's a vertical halfwave endfed and the gain is
2.4ish DB over a dipole and that's all. If executed correctly it
will be better than a 1/4wl groundplane but not by any fanstastic
amount. For many applications that is a "good enough" antenna.

Allison


What's the mechanism which gives this half wave antenna 2.4 dB gain over
a half wave dipole?

Modeling shows the gain to be the same as a dipole, if you can manage to
keep the current on the outside of the feedline to a small value. If you
can't, the gain in the horizontal direction typically becomes less than
a dipole.

Roy Lewallen, W7EL