My simulations indicate that as you adjust the array elevation
above 5 degrees the vertical lobe begins to broaden. At about
16 degrees elevation, the vertical 3 db beamwidth is 24
degrees (from 3 to 27 degrees). It's not the prettiest pattern one
has ever seen, but it should work quite nicely for general purpose
dxing and/or contesting.
Clay
>
> Yes, that's absolutely right, Jim. I am guilty of thinking "in the
> box". If you remove the straight jacket of the conventional Yagi
> with fixed tuning/phasing, and exploit the large design space
> allowed by the independent element length control, you can
> probably do some interesting things. It would be an interesting
> study to figure out the various possibilties for elevation pattern
> control. You could then feed that information to the SteppIR
> controllers to get an electronically steerable elevation pattern.
> I wonder if this is what the owner has in mind (maybe he isn't
> as misguided as we first thought)?
>
> Still, even when you open up the possibilities afforded by
> arbitary element length control, it is not clear to me that you
> can achieve as clean an elevation pattern as a conventional
> vertical stack in the range of interest (say 3 to 15 degrees
> TOA). Even if you synthesize nulls looking toward the ground
> at a specific angle, you still are fighting the grating lobes that
> want to form at other angles due to the large spacing between
> the array and the ground image (e.g. can you cut down the
> ground illunimation over a broad range elevation angles without
> cutting down the corresponding direct radiation and achieve a
> broad main lobe close to the horizon?).
>
> 73, Mike W4EF...............................
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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