Hello Jack,
I use PHD with my spectrographs.
(Note with PHD even when guiding properly, the star tends to move backwards and forwards across the slit because half the star is hidden when the star is slightly off the slit so it over corrects. There are guiders which work on the split image of the star on the slit but I have not used them)
You say the star wont guide on a star, the star wont stay on the slit.
Do you have the green square round the star with a green cross at the guide position?
Did the training work ok? First time you run (or if you hit shift when you start to guide) the cross is dottted yellow and the star is moved in X and Y to calibrate the guiding. (If the star does not move, there is a problem communicating with the mount and you will get an error message)
Does the star and green square stay near the guide position (centre of green cross) or does it continuously wander off?
If the star is staying around the right position but is moving around the guide position too much try guiding off the slit. Does it work ok then ?
Cheers
Robin
