[amsat-bb] Re: How to calibrate the azimuth angle?
ka3hsw at earthlink.net
Thu Dec 27 07:27:03 PST 2007
----- Original Message -----
From: "Tony Langdon" <vk3jed at gmail.com>
To: "Chiu-Teng Tsai" <n2693415 at mail.ncku.edu.tw>; <amsat-bb at amsat.org>
Sent: Thursday, December 27, 2007 3:30 AM
Subject: [amsat-bb] Re: How to calibrate the azimuth angle?
> At 04:08 PM 12/27/2007, Chiu-Teng Tsai wrote:
>> I am Chiu-Teng Tsai (BM6ERA) from Taiwan. Now we are building a
>> mobile ground station. One of our problem is how to calibrate the
>> azimuth angle. Use compass only, or any better solution? Thanks for your
> Azimuth is given in degrees from true North. A compass is fine, if
> you know the magnetic declination (i.e. the difference between true
> North and magnetic North) for your location. That information should
> be readily available on the Internet.
> 73 de VK3JED
If the declination is less than half of your antenna's 3 dB beamwidth, you
can probably ignore it and just point to magnetic north. With a dish, it
becomes significant, however.
Another tried and true method is to track the sun, and adjust your antenna
mounts and rotor mount to cast the smallest shadow ("X") of your antennas on
the ground, or sight thru the antenna boom ("boresight") while tracking the
moon (DON'T look at the sun!).
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