[rjbruce (Rob)]

Hi All,

I have an interesting problem that I'm hoping someone might have come across before.

I have a Celestron CGEM mount and am using PHD with one of AstroGene's USB to ST4 autoguiders to guide the scope during imaging. PHD will fail on calibration stating that it can't move the scope in the "North" direction and hence guide only in RA (which is does do just fine).

I have checked the voltages on the ST4 end of the autoguider cable and they all sit at 5V and are pulled low (to 0V) when the guider signals to move in a certain direction, even North. So I am assuming from this that the AstroGene unit is working well but the mount is not accepting the "go North" command.

I have also used the "Manual Guide" mode on PHD and can get the mount to move East, West and South, but just not North.

I have set the autoguide settings on the mount to 0 and to 60 and 70, but that doesn't appear to help the North issue, just makes it more sensitive in the other directions.

The mount will move North if the Nexstar controller is used, so the drive does work in that direction.

Look forward to any ideas.

Thanks,
Rob