Hi Dave,

A user of the LVB Tracker, SatPC32, and a Yaseu G-5500 *can* do 450 AZ and 180 EL if they choose to. It's all configurable. The LVB Tracker must be calibrated with either 360 or 450 for azimuth , and either 90 or 180 for elevation. From there, the operator just has to make sure the SatPC32 rotor setup "matches." Users can pick and choose whatever combination matches their station needs or desires (450/90, 360/180, 450/180, 360/90).

I tend to use 90 deg because it's simpler from a "coax hanging" perspective. And I also use 360; in my hands, the 450 seems to "lack linearity" if that makes sense. By that I mean, if I calibrate to 450, it's like 360 isn't quite really 360.... So, I just use 360 and it's fine.

73,

Mark N8MH

On Mon, Feb 8, 2010 at 7:14 AM, David Johnson [email protected] wrote:

Hi Clive,

Dave is correct about MacDoppler, it works a treat.

What Don (the writer on MD) and I do for GENSO is set a rotator dead spot and indicate to the software that it should allow the elevation to flip the rotators 180 degrees before the pass. The prediction algorithm then knows that if the azimuth passes through the dead spot during the predition, it should flip the rotators beforehand and output the adjusted azimuth position.

I'm sure that some of the windows trackers do this.

AFAIK none of the existing programs allow for the 450 degree rotation.

733

Dave, G4DPZ

On 08/02/2010 10:59, Dave-K7DAA wrote:

...

Clive:

If you're running Windows, this won't help you, but MacDoppler does this easily, and without operator intervention.  I'm using the same equipment you are, but with a MacBook Pro laptop, and it works beautifully.

73,

Dave - K7DAA

On Feb 8, 2010, at 2:17 AM, Clive Wallis wrote:

...

Hi,

A problem that I've had for many years is how to track when the satellite's azimuth crosses across the rotator's end-stop,  ie. when the azimuth changes from 0 to 359 degrees.

My rotator turns between 0 and 450 degrees, so it should be possible to use  angles between  360  and 450  to  overcome a sudden  transition from  0 to 360 degrees.

As the pass data is  available within the tracking program, it should be feasible to deal with the problem in the program.   Do any tracking programs include this feature?

A possible solution would be to use a small PIC between the computer and tracker, which could modify the commanded azimuth.

I'm using a Yaseu 5500, LVB tracker, Sat_Explorer tracking program and WinXP.

Any help,  suggestions or comments would be most welcome.

73     Clive    G3CWV

Hitchin, North Hertfordshire, UK _______________________________________________ Sent via [email protected]. 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

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Hi,

Many thanks to everyone who replied to my request for information.

I thought that SatPC32 might offer a solution with the rotator set up for 450/90 operation.

AFAIK my tracking program (SatExplorer) offers an option to flip the elevation, to avoid traversing round the end-stop, but I didn't really want to do that.

I will contact the author of SatExplorer to see whether 90/450 operation is possible.

Sorry Erich about the bounce problem, should be better now :-)

73 Clive G3CWV

Hitchin, North Hertfordshire, UK