Rick, I hear what you are saying but why not just use your S meter. Get a
ham that is a mile or two from your QTH and have him (on a dead band) key up
a reduced power carried. With your beam pointed at him note the S meter
reading and then rotate off until the S meter drops into the notch (or what
ever value of dB you want) and read out your rotor angle. The difference
between the peak direction and the desired dB loss direction is the angle I
think you are looking for? You say you know where North is so if you have an
accurate North what more do you need? Seems you are more interested in the
actual antenna pattern than anything else. BTW, you will need to do that on
each band if the beam is a multi band beam. 73, Ron W8RJL
----- Original Message -----
From: "Rick Kiessig" <kiessig@gmail.com>
To: <towertalk@contesting.com>
Sent: Friday, October 26, 2012 12:12 AM
Subject: Re: [TowerTalk] Calibrating antenna direction and using chokes with
a beam
Thanks for the replies so far -- as I said in my OP, I know how to find
true
north. I already went through the compass/declination/rough-alignment when
I
first put the antenna up. I know about the shadow technique as well [FWIW,
in the southern hemisphere the sun is in the north and shadows point due
south at solar noon]. What I'd like to do now is calibrate pointing
direction with some degree of accuracy, based on something more concrete
than just eyeballing it.
Also, I realize a 3-el Yagi has a reasonably wide 3 dB forward lobe (appx
66
deg). I'm not concerned with the accuracy of where I'm pointing the center
of the lobe; I'm ultimately interested in managing placement of its edges,
where gain drops off quickly.
73, Rick ZL2HAM
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