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Re: El/az rotator options

The minimum pointing accuracy of your rotor system should be one-half the 
beamwidth of your narrowest-beamwidth antenna, so check the specs of the 
antennas you plan to use.  Most of us are probably using the Yaesu 5400B or 
5500 rotor systems, and doing just fine with them.  Others manage quite well 
with old TV antenna rotors.  If you have a very high gain dish (hence, very 
narrow beamwidth), or one that presents a high wind load, you may need the 
beefier M2 system.

Another player in the AZ-EL market is Alfa-Spid 
http://www.prosistel.net/home-e/default.html.  Also a bit on the pricey 
side, but less than the M2 combo.

You might also want to look at the FOD-Track board for controlling your 
rotors:  works plug & play with most popular tracking software and the Yaesu 
rotor , can probably be adapted to the M2, and it can be built for under 
$30.  http://www.farcircuits.net for the bare board.  If you are willing to 
dedicate an older PC with IST slots to tracking duty, you could look for a 
used Kansas City Tracker board...  can probably be had for under $75.

George, KA3HSW

----- Original Message ----- 
From: "Christopher J Galbraith" <cgalbrai@umich.edu>
To: <amsat-bb@amsat.org>; <amsat-edu@amsat.org>
Sent: Tuesday, February 28, 2006 4:38 PM
Subject: [amsat-bb] El/az rotator options

> Hello groups,
> We are designing an amateur radio satellite system for the club station at
> The University of Michigan (W8UM) and need some help in assessing our 
> needs
> and specifying hardware for the elevation/azimuth tracking system.
> Our immediate plans are to use Yagi-Udas on 2m and 70cm for use with 
> current
> LEO satellites on these bands.  In the future, we plan to add capability 
> for
> S-band and higher frequencies.  Essentially, we want to be sure the system
> we build today is able to meet the capacity and pointing accuracy
> requirements of higher frequency satellite work.
> Based on these requirements, we have found two options for the el/az
> tracking system:
> Option 1: Yaesu G-5500, W0LMD Satellite Tracker Jr. interface, cost ~ $800
> Option 2: M2 OR2800PX and MT-1000A, cost ~ $3000
> We understand that the M2 system affords much larger capacity (more, 
> larger
> antennas) and pointing accuracy.  But we are having a difficult time
> assessing if the performance is worth the extra $2200.
> To ask some specific questions,
> 1. What sort of pointing accuracy should we accept as a minimum?
> 2. Would the Yaesu system be reliable with a 2m Yagi-Uda, 70cm Yagi-Uda, 
> and
> a small dish?  (Assuming the wind load is within spec.)
> 3. Are there other el/az rotator manufacturers/products we should be
> considering?
> We would be grateful for any advice!
> Thanks and 73,
> Chris KA8WFC
> ----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
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