Phd guideing issue.

[redfox1971]

Hi i seem to have a problem guideing,my telescope is a celestron cpc800 on a heavy duty pro wedge,i start by doing a eq north align useing eq 2 star align i then select a star low in the south and do a polar align,align mount useing my dslr and apt software,i follow the instructions and then adjust wedge to centre star,next i start phd guideing i am useing a qhy5 on my guidescope useing a st4 cable,i start the calibration and it takes about 21 steps each direction to calibrate and start guideing it dose seem to track across the centre roughly but when i take images of 300secs i get slight star trailing,i have noticed if i select north and not auto i am getting almost near round stars,what dose this suggest? is it maybe a backlash issue on the scope,dose it mean i have a problem on alt-dec up-down on the scope,i do have the scope balanced,was thinking of trying celestrons pec tool,any help welcome.

[Davey-T]

Ah the joys of guiding, are you sure your PA is ok , if you turn off dec guiding you can see if the guide star drifts up or down while you're imaging.

Hours of endless fun experimenting with PHD settings

Dave

[redfox1971]

Hi davey the images i have taken of andromeda seem to go sideways and not stay in same position.

[Freddie]

Sounds like your PA is out a touch.