After the fun with getting guiding working on Saturday night I had even more trouble on Sunday night.
The symptoms were a bit weird. For starters I had no luck getting APT Goto++ working. I’d get within a reasonable distance from the target then the fine adjustment just didn’t seem to work. Then when I did get the target finally centred PHD2 guiding kept drifting off in DEC.
Eventually I gave up trying to image anything and started to diagnose the problem. Running the PHD2 star cross test gave me a T shape with no/not much downward movement in the south direction. I then went back to the Goto++ and yes, when looked closely it was targeting perfectly in the RA but if the target needed adjustment south nothing much was happening.
After a bit of poking about in the dark I found that the retaining blots on the DEC adjuster lose. So at one in the morning I was stripping down the DEC adjuster and readjusting it.
What I think happened is that when I striped the telescope down about a month ago using this guide (which is really good) I’d been really careful to only do the bolts up finger tight (as instructed). Of course one of the bolts had worked lose.
So this time I’ve made sure the retaining bolts and the adjustment bolts are done up quite tight and adjusted them off with the small adjusting grub screw in the middle. I’ve also done the RA again for good measure.
Trying it the next night I was getting 5 minute exposures so I’m happy.