A FULL WAVELENGTH Wire, fed in the CENTER
acts as TWO - Half Waves in Phase with a typical
dipole pattern, narrowed to about 50+ degrees beamwidth.
The feed impedance is extremely high (~3000 ohms or so).
When fed 1/4 WL from the end, it acts as a SINGLE
Current Fed Long Wire with 4 lobes. Feed impedance
is in the 100-150 ohm range.
Tom N4KG
On Mon, 22 Apr 2002 EDT N4CW@aol.com writes:
> I have enjoyed working with ELNEC and EZNEC and modeled my favorite
> wire
> antenna, a full-wave antenna, fed a quarter-wave from one end. In
> free space
> it's a clover leaf, and above real ground it's got a "double kidney
> bean"
> pattern with nulls off the ends. Interestingly enough, the models
> show the
> same patterns when it's center fed. I haven't modeled that antenna
> by moving
> the feedpoint between center and 1/4 wave, but I suspect that for a
> given
> length of wire, it will radiate the same, regardless where it's fed.
>
> Maybe I'm generalizing a little too quickly, maybe not. Antenna
> scholars on
> this forum will set it straight.
> 73, Bert N4CW
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