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Re: Re: True North vs Magnetic



Nick:

My favorite method is to align with the Sun.  Most tracking programs
will give a very accurate Solar position.  For example, I point the
antenna to be aligned and then check the shadow of the boom on the
roof.  For a dish, the shadow of the feed should appear in the dish center.
I also use a two dimensional Solar noise plot to check the dish pointing.
At its highest elevation around noon the Sun is due South of you.

The Moon can also be used but sometimes the accuracy of the tracking
may not be as good.  The shadow is a lot harder to see.  If you note the
rise and set azimuth of the Moon or Sun you can get a good feel for East
and West points.

If all else fails align to the pole star, Polaris.  It is currently within a
degree
of true North.

Also, remember that unless you have a very high gain (>20 dB) antenna,
the tracking accuracy may not be very important because of the wide beam
width.

Regards,

Richard W5SXD

K1uxbMa@cs.com wrote:

> All;
> I'm using an old Army magnetic compass to take reading on the antennas and
> setup the
> correct headings on the shack indicators. Most are probably familiar with
> this compass
> ,there are two partial lines on the face which indicate Magnetic and True.
> Question is which is which ? Ture looks to be about 15 degrees east of
> Magnetic.But this varies with
> location doesn't it ?  Any help appreciated. Tnx
>
> Nick_K1uxb@Amsat.Org
> AmSat M#22708  ARRL M#
>
> Save_Time Go_Online
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