Date: Tue, 16 Jun 2020 08:15:53 -0700
From: jimlux <jimlux@earthlink.net>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Inverted Vees
> Jim Lux wrote
>
> These are theoretical dipoles, so infinite null.
>
>
<The hairy ball theorem says that isotropes don't exist in the real
<world. And neither do perfect dipoles. <grin>
<I'd be impressed by a 30 dB null on a real dipole on real supports in a
<real environment.
## Perhaps Grant Saviers or Tim Duffy can chime in..as they both have 80m
rotary dipoles ?
To tweak the rotary dipole for a deep null, the rotator would have to be
going really slow.
A T2X, or any rotor that turns at 1 rpm is way too fast. Thats 6 degs per
second.
A PP is only 3 degs per sec. A PP with the green heron box can really be
slowed down,
and ditto with the OR-2800. The OR-2800 can be slowed down to .1 deg
increments
on the digital output, like say 89.1 and then 89.2 then 89.3 etc. M2
calls the ultra slow
mode..... bumping.
## Sure, free space models will show a sky high, almost infinite FS....
but practical
dipoles are above dirt. Still, if the rotor was slowed right down, Im
betting the
null off one end, could be directed at one station, resulting in a real deep
null.
## Same thing could be applied to a yagi....with offending station off one
side. Again,
the array would have to be turned really slowly. It would be an interesting
experiment..esp for 40M broadcast.
That SW broadcast junk on 3925 would be a good source for a solid steady
signal to experiment on.
Jim VE7RF
Jim VE7RF
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