I have an array like this, except it has 7
elements. One in the center and 6 in a
circle of 3/4 wl diameter. However, it
is an all driven array, not parasitic.
There are 3 phasing networks. One fires
in the direction of any of the six outer
elements (selectable) with 9 dB gain over
an individual vertical. The second phasing
network fires in between outer elements with
8 dB gain. The third phasing network is
omni directional with 2 dB gain. I have
a 40 meter version of this on the air,
an 80 meter version is under construction,
and a 160 meter version is being planned.
I also have a contingency plan for 60 meters,
if we get that band.
I fooled around on EZNEC with parasitic
excitation and I was able get within a dB or
two of the driven gain that way, but then I would
have to worry about tuning the elements. With
a driven system, I just force the currents and
it doesn't particularly matter exactly how the
antennas are tuned.
Rick N6RK
> Has anyone played with a 3-element vertical wire yagi, (electrically
> rotated) centered around a common point?
> (no rotor)
>
> IE: something resembling this (birds eye view) :
>
> . .
> .
> . .
>
>
> The center dot being a 1/4WL element. Each outside element (I'm thinking)
> could be the length of a reflector
> but with a small coil or linearly loaded piece of wire at the
> bottom, which
> could be shorted by a simple SPST relay,
> ensuring it was then short enough to be a director.
>
>
> Mike VE9Antenna Antenna
>
>
________________________________________________________________________
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Order online at http://store.eham.net.
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