Potential guiding issue

[JohnP]

Hi All,
Might have a potential guiding problem. Was out last night for first time in ages – playing around with EQMOD & some other bits of S/W. All seemed to work well except when I calibrated my guide scope it wasn't moving enough during calibration. I checked cables etc. & think all is OK.  I guide using a modified webcam & parallel port on my Laptop to ST4 port on EQ6. E,S,W seemed to move OK but N was causing a problem.. Anyway, eventually I got it to calibrate by doubling the time it had to move motors during the cal procedure. Cal procedure said backlash was like 7500msecs.. normally it is less than 4000msecs (has been over a year since I used scope though). I was playing around with imaging Pacman Neb in Cass – this was relatively close to North & was wondering maybe issue was because where I was pointing...?

Any ideas. Thks,  John

[Fay]

I cant calibrate using PHD when pointing near North. i usually go somewhere else calibrate  then go back to what i want to image

[The Thing]

You found the correct solution John. On the EQMOD Yahoo group this comes up every so often.
Also make sure the EQMOD backlash compensation time setting (top left under guide rates) is about 20ms (the default I think)and check you are unbalanced the right way for the scope position. Not that you'll get a chance to try it now the weathers changed

[Rocket Pooch]

John,

On EQMod there is a slider for Guide Rate, set it to 5, its set to 1 by default and the mount won't move a lot.  Also, why not just guide with ASCOM, it cuts out the need for the cable and port.

Chris

[MarkS]

Also, why not just guide with ASCOM, it cuts out the need for the cable and port.

Guiding with ASCOM - what connects to what?  And what do you run?

[Mike]

You just use the EQ-MOD cable. It sends guide pulses from the laptop to the mount. No need for the ST4 cable.

[mickw]

It's been a (long) while but I think it's been over simplified a bit.

Guide camera connects to laptop using USB and an ASCOM driver (this does away with the guide cable) - This is with a QHY.

Guide camera now speaks to the ASCOM jobby, CduC (or whatever) and the mount.

Put kettle on or open case of beer and wait for a bunch of images 

[MarkS]

So no further need for the Shoestring GPUSB then?  Does that mean no more PHD Guiding either?  Are you dithering?  

[mickw]

Oops
Yes to shoestring thingy, that makes PC speak same language as mount
Yes to PHD that is software interface with output from guide camera
Yes to dithering (actuated by capture software - APT and others I can't remember)

[MarkS]

Mick - if you are using the Shoestring thingy that plugs into the mount's ST4 port and you're using PHD then it sounds like you are doing the same as me.  But I suspect it is not doing the same as Mike because he's using pulsed guiding from EQMOD and has no ST4 cable.

I'm trying to clarify what Mike does ...

[Mike]

I just have the USB cable from the guide camera and an EQ-DIR between a USB port and the hand controller socket. EQ-MOD and PHD take care of the rest using pulse guiding.

http://eq-mod.sourceforge.net/docs/EQASCOM_Guiding.pdf

Once up and running use the pulse guide monitor to help you fine tune the settings.

[JohnP]

Well prob I have is that I still use my old lx exposure webcam with no st4 port. It uses parallel port to control the lx exposure so I have cable from parallel port to webcam anyway. Having an extra from parallel to mount st4 is not a prob. I need to check if the guide prof I use supports ascom. Thks, John.

[Rocket Pooch]

I'll bring my spare guide cam to France in case you need it.  As well as the parallel port and spare laptop.

Tools, spare tyre, camping kit and ditch bridge (there is a road I want to drive on).

[JohnP]

Excellent - sounds good - cheers mate.. Off roading or dirt lanes sounds like fun as well

[RobertM]

I'll bring my spare guide cam to France in case you need it.  As well as the parallel port and spare laptop.

Tools, spare tyre, camping kit and ditch bridge (there is a road I want to drive on).

You're just showing off now