Guiding doesn't always work properly

[RobertM]

Why don't you do away with the ST4 cable and apply the corrections direct to the mount using it's serial cable from the PC ? If memory serves me correctly that ST4 cable is one of the least flexible, especially if it's one of those with a flat profile.  The corrections get applied from the PC anyway (for a computer controlled mount) so cutting out that cable and the correction electronics in the QHY5 would be one less cause of possible problems and be simpler.  If you have ASCOM then most software including PHD/MaximDL will work with that configuration.

Robert

[Carole]

Robert are you referring to the cable that you sold me that connects the handset to the PC?

Currently I am unable to control the Mount from the PC as it doesn't work on EQMod and I have not yet been successful in running it on anything else such as Starry night.  I almost got it set up once, but not entirely.
So unless I have misunderstood you this isn't currrently an option. 

I've got Ascom installed on the laptop when I installed PHD. 

Carole

[MarkS]

Use the same setup you had with the SC3 camera but just substitute the QHY5

I still use the Shoestring GPUSB to control the mount.  Using this setup meant it was easy to switch guidecams when my QHY5 failed the other night.

[Carole]

OK: Update.

Guiding is still intermittent, but on the whole better at the last imaging session, but there were still times when it was poor.  Watching the graph, most of the time the RA and Dec pulses were close to the centre of the graph, but occasionally it went astray. 
Of 30 subs:
15 were good
9 were slightly elongated
6 were crap

On two people's suggestion I have now bought myself a regulated PSU, and also bought myself a second ST4 cable, so I can check that out too.  However my original is a curly cable so should be some stretch in that. 

This has been a protracted problem, so I just hope the regulated PSU will do the trick.

Robert, you mentioned in an earlier post

the RA should be setup so the motor is driving against the slight off balance

.  I can't quite get my head around that.  Should the side by side bar be weighted to the East?  Or have I misunderstood?

Carole

[Ian]

Robert, you mentioned in an earlier post

the RA should be setup so the motor is driving against the slight off balance

.  I can't quite get my head around that.  Should the side by side bar be weighted to the East?  Or have I misunderstood?

Carole

No, not side by side, that affects the dec. The main counterweight should be set to just be slightly heavy. It ensures that the gears on the RA drive say firmly in contact and don't float around in the backlash unpredictably.

[Carole]

Thanks Ian, makes more sense, I think some-one gave me some duff info (not in OAS I hasten to add), and I didn't think it sounded right, so was basically checking. 

Carole