Stuart, that's a good point.
I began using the horizontal loop in field day over 25 years ago, Initially
there were lots of people challenging the theory of the antenna (with nulls
and all). But they couldn't challenge the continuous string of first,
second, or worst case third place the antenna brought us in the contest.
People told me it was a cloud burner - good for NDIS. I worked tons of
pile-ups into stateside (from Europe) on 80m both on CW and SSB. Never
fails. So much for their theory.
It's always nice when a good-working antenna can be backed up by theory.
One thing I have never understood is many people's reluctance to use (or
even try) an antenna found to be good in practice, yet not proven in theory.
Oh, I'll admit I've tried a lot of stupid ideas and many have flopped, but a
few have turned out to be secret weapons. Some (e.g., the EH-Antenna), even
life savers - if you are space limited.
73
Rick
-----Original Message-----
From: tentec-bounces@contesting.com
[mailto:tentec-bounces@contesting.com]On Behalf Of Stuart Rohre
Sent: Monday, June 14, 2004 1:51 PM
To: tentec@contesting.com
Subject: Re: [TenTec] Vertical Antennas (was Radials)
My take on antenna nulls from arrays comes from playing with extra large
Horizontal Loops at Field Day, up to 1200 feet of wire circumference!
Classic modeling shows nulls in the multi lobed patterns of symmetric loops.
However, plotting states and sections worked shows a good fill in in
expected null zones.
Current ionospheric theory says there is not a uniform layer, but clouds of
ionization. It is possible that the reflections from varying ionosphere
tends to fill in the areas of null you would otherwise find.
Or looking at it another way, a station beams his signal away from his area
which is in your null, and it refracts and reflects such as to fall within
your major lobes.
Phasing does work, but on antennas that squirt signal theoretically in
various lobes, the nulls may not be complete from on the air observations.
Either stronger signals over come them, or conditions bend the lobes and
nulls effective directions. Kind of hand waving, but that is what we have
seen over 6 years of careful Field Day attention to large Vee beams, Double
Zepps and horizontal Vees.
73,
Stuart
K5KVH
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