Autoguiding help please!

[Glasspusher]

Hi Guys, would be grateful for some help, hopefully it is something silly I am missing. I am using an eq6 pro with eqmod all seems to connect up OK through the handset. Trying to use PHd for guiding but after about 2 mins an error message pops up about the guide star not moving enough!! Sorry, cannot remember the exact wording of the message. Any thoughts please?

Thanks

John

[chrisshillito]

John,

Presumably this is occurring during PHD calibration. - I'll assume it is...

During calibration PHD attempts to move the star image around by issuing a guide pulses to the mount. If PHD is not detecting enough movement then this could simply mean that given your particular guiding resolution the length of pulse issued is not long enough. PHD has a "calibration step" setting that you can lengthen the calibration pulses.

If changing the calibration step doesn't produce greater movement then it could be a cable fault (if using ST-4 guidng) or perhaps you will need to select a faster guidng rate in EQASCOM.

Chris.

[Beardy Bob]

...or it could be that you're picking a hot pixel instead of a star. Thought I'd mention it 'cos I recognise the error message from when I did it!

[Glasspusher]

Thanks guys, Chris I will have a play with the calibration step when I get the opportunity, sounds like a possible solution!

John

[Ant]

Chris is right - you do not mention what scope you are using?

For this problem that is important, my guess is that you are using a short FL refractor??

Click on the brain (down the bottom), and then increase the calibration step. The shorter the FL the higher the number needs to be.

I image through an ED80 and have it set to 1000 (as you can see below).

It could also be the hot pixel suggestion or something as silly as not having the RA axis locking bolt tight enough (which I did early sunday morning...

Cheers

ant

[Sparrow]

I agree with previous comments re. calibration steps or possibly hot pixel chasing - it can and does happen - I've been guiding for a year now and last time I was out, forgot to take the lense cover of the guide scope and very efficiently set PHD to calibrate on a hot pixel!!!! Easily done. Couldn't understand why I wasn't seeing many stars to choose from!! - what a wally I am.

[Glasspusher]

Thanks Ant and Sparrow, appreciate your input, just need some decent weather now - looks promising for tonight but with high winds!!

John