Help with Phd guiding please!

[zcapp96]

I am having a go at autoguiding using phd with little success at the moment, it took a couple of hours just to get the laptop to control the mount. Once I finaled managed that I tried to calibrate on a guide star, clicked on a star and got the green box. then clicked on the start guiding button. Yellow cross hairs appeared but after a couple of minutes an error message came up saying 'RA calibration failure, star didn't move enough'. Does anyone know how I can get past this? I'm using a HEQ5 upgraded to goto with a ST80 and a DMK camera. I have a serial to usb and cable to the handset, both bought from astronomiser and am using EQMOD.

Steve

[Tim]

Are you by any chance using a target near the pole? They dont move much.

But you can make it happen.

Set your calibration step to at least 2000ms. I'll explain why it works another time, but you may still get some guiding done tonight!!

[Tim]

Out of interest, what are you using to connect PC - Autoguide port on the mount ?

[Dave Moulton]

Are you by any chance using a target near the pole? They dont move much.

But you can make it happen.

Set your calibration step to at least 2000ms. I'll explain why it works another time, but you may still get some guiding done tonight!!

Steve, TJ makes a good point.increasing the calibration steps may help. It sounds as if you are pulse guiding the mount via EQMOD and not using the ST4 port to guide.

If correct then you may have to up the anti on the pulse guide settings,this may help if you are pulse guiding. the settings are on EQMOD I think the default is set at 100ms pulses, I would lift this setting to about 400ms and see if the star moves then. I had this same problem a while back and lifting this setting cured the problem for me.

Dave Moulton

[zcapp96]

Thanks for your help, will try it next time the skies are clear, was trying for something in ursa major so was quite close to pole.

[Tim]

It's a good thing in a way, as it means your ploar alignment is pretty good! But you can make PHD push the stars around so that it can get a measure of what it needs to do.

Good Luck!

[George]

I'd also play about with the exposure time, 2 seconds works for me most nights with my LP, when its crystal clear and good seeing I can reduce this.