[amsat-bb] Re: Calibration of AZ/EL

["Wayne Estes W9AE" <w9ae@xxxxxxxxxxxxx>]

Ben K9BF wrote:

How are most of you calibrating your Az/El? With a compass and level?

Wayne W9AE replies:

Most people calibrate az/el by pointing at an object that has a known
azimuth and elevation.  Convenient things include the sun, moon, and Polaris
(the north star).  I generally use the sun and either look down the beam of
a yagi towards the sun, near sunset when the sun isn't too bright to look
at.  Or you can look for the minimum shadow of the yagi boom if it isn't too
far away from the roof.  Most satellite tracking programs display the az/el
of the sun and moon.  Polaris is north (approximately) at an elevation equal
to your North latitude.

I calibrate elevation purely by eye.  I compare the elevation of a yagi boom
to nearby objects that are known to be horizontal or vertical.  Like others
have said, you are doing fine if you can get within 2 degrees.  You don't
need more accuracy than that unless you have a huge dish.  Besides, you can
always manually swish your rotors to peak the signal strength of the beacon.

Make sure the elevation of your yagi and dish are aligned, though.  That's
tricky with an offset dish, and can be somewhat difficult even with a prime
focus dish.

Wayne Estes W9AE
Mundelein, IL, USA


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