Re: [amsat-bb] AO-40 dish

[JoAnne Maenpaa <wb9jej@xxxxxxxxxxxxx>]

Hi Glenn,

> Any thoughts? Pointing might be a problem. Thought of building
> a tripod mounted to the dish and manually point it for the 
> major part of the pass.

Since I just got my dish installed and the downconverter work-
ing I've been doing the Armstrong Rotor on my AO-40 antenna.
There's a picture at http://home.earthlink.net/~maenpaa/

Sooner or later, time permitting, I'll figure out a mechanical
way to rotate it.  I've been pointed towards C-band TVRO
actuators as the best approach to automation.

One thing that surprised me about the big dish was how critical
aiming was.  Once centered on AO-40 (going by strongest signal
received from the beacon) I lose the bird if I move the dish
more than an inch or so left/right or up/down.

I take the az/el info from the tracking program and translate
it into my Armstrong Aiming Parameters (AAP's).  I started out
using a compass for az and a plain 'ol protractor for el.  After
a few weeks of practice I'm beginning to be able to eyeball 
where I should point it.

While AO-40 is reasonably far out I need to re-adjust its
pointing about every 20 minutes.  I just keep the beacon freq.
in the other VFO and use it to reposition the dish for best
signal.

Hope this helps ... go for it ... give your dish a try!

73 de JoAnne WB9JEJ
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