[amsat-bb] Re: G-5500 Orientation

Greg D. ko6th_greg at hotmail.com
Sun Oct 10 23:33:30 PDT 2010

Hi Dean,

Usually an elevation rotor is mounted so that the antennas are directly horizontal (zero degrees) when the rotor is positioned at zero.  Then the satellite elevation is the same as the rotor's position.  45 degrees up is, well, 45 degrees.  Straight up is 90.

What others are discussing is a further refinement, where the rotor can swing past 90 degrees, into what is known as "flipped" operation.  For this, the software and rotor need to both be capable of it, as well as your installation (watch for tangled cables!).  If your Azimuth rotor is mounted so that it stops at +/- North, then a satellite pass that crosses the line from North to you will force the rotor to swing clear around when it gets there.  To prevent this 60-second outage, a flipped pass will turn the antennas on their back and swing them around 180 degrees, effectively giving you an Azimuth rotor that has its stops aimed South.  Then you can work the satellite through its entire pass.

Hope this helps,

Greg  KO6TH

> From: dean at n1ety.com
> To: amsat-bb at amsat.org
> Date: Sun, 10 Oct 2010 13:07:08 -0400
> Subject: [amsat-bb]  G-5500 Orientation
> I am installing a G-5500 Elevation rotor and trying to determine
> orientation of elevation with reference to software specifically
> rtrcontrold for Linux but I'd suspect this would be typical to most PC
> applications.
> If a sat is 45 degrees above horizon should rotor control read 45 or 135
> degrees on the hardware control dial?
> What I'm asking is when I want to mount antenna where 90 degrees is
> horizontal or vertical?
> It seems natural that midway point is horizontal but midway point is 90
> degrees. I don't think I ever have a reason to point antenna into the
> mud so it makes most sense that midway 90 degrees is straight up??
> _______________________________________________
> Sent via AMSAT-BB at amsat.org. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

More information about the AMSAT-BB mailing list