[TriLUG] FTA -- Probably OT, but...

[Joseph Mack NA3T]

On Wed, 6 Jun 2007, Brian McCullough wrote:

> To make a long story longer, in the past I have owned a "big" dish (
> C-band )

I'm a ham radio operator with a little experience in this 
area. It might be easier to talk about this over the phone. 
I'm at home this afternoon/evening (wed) if you want to give 
me a call.

It would help if you had the diameter of the various dishes 
and the frequencies they were designed to operate, the 
focal lengths (how far the receiver is from the dish) and 
the aperture of the horns on the receivers, all to within 
25-50%.

Aiming is important. Unless you can get az/el to within a 
couple of degrees, you won't find the bird. Have you set up 
one of these from scratch with accurate levels? Do you know 
how to compensate for the squint angle? Is all the mounting 
hardware for the receiver and dish rock solid so that the 
signal will return to normal when you give it a good thump 
(or the wind blows)?

The receivers usually have cheap lossy coax, with 
F-connectors, which give erratic connection and should not 
be used outdoors (or anywhere). You will go crazy trying to 
find a bird with the errratic connection you get with this 
hardware. I suggest changing these to BNC/TNC first chance 
you get.

Do you have anything working right now as far as getting a 
signal and detecting changes in signal that respond to 
aiming (even if you don't have authorisation to descramble 
it, and even if it isn't the bird you finally want)?


Durham (919)-401-2047

Joe

-- 
Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
generator at http://www.wm7d.net/azproj.shtml
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