I don't have experience with 3rd party controllers but the position reporting is fundamentally different. Instead of potentiometers indicating the present az/el, there are just pulses indicating when the motors have traveled a degree.

So a little more work is associated with keeping track of the heading, and I haven't heard of a compatible 3rd party controller, but I don't foresee modifying one to do so as particularly challenging.

On 2/7/10 10:12 PM, amsat-bb-request@amsat.org wrote:

Message: 5 Date: Sun, 7 Feb 2010 17:34:13 -0400 From: Bruce Robertsonve9qrp@gmail.com Subject: [amsat-bb] lvbtracker (or other) and AlfaSpid rotors? To: AMSAT-BBamsat-bb@amsat.org Message-ID: 49657a761002071334n17015d9cm9de43e37134395f2@mail.gmail.com Content-Type: text/plain; charset=ISO-8859-1

The Alfa Spid price list http://alfaradio.ca/docs/AlfaSpid_Price_June15_2009.pdf indicates that the az/el rotor alone is about $600 (CAD) cheaper than the rotor with controller. I understand that this controller is a very nice piece of kit, and many are quite pleased with, for instance, its mouse interface. However, that additional charge moves the purchase from the 'maybe one day' to the 'no way Jose' column.

So I'm wondering if anyone has experience with third-party controllers to operate the Alfa Spid rotors. Are they electrically similar to other rotors, or is the proprietary controller absolutely necessary?

73, Bruce VE9QRP -- http://ve9qrp.blogspot.com