PHD and CG5

[seeker372011]

I have never been able to get PHD to work with my CG5 mount..is there something I'm doing wrong?

Guidedog works fine, but everyone else seems to think PHD works really well so I wonder if I'm doing something stupid

[Geoff45]

Well I can't get guidedog to work with my gm8, but PHD works fine! You can never tell with software.
Geoff

[Dennis]

Can you calibrate uisng a bright star in PHD? That is, does PHD drive the CG5 E-W and N-S to perform a calibration run before it auto guides?

Or, are you saying it won't even connect?

Cheers

Dennis

[Harpspitfire]

i think if your all connected (it tells you at the bottom) you need to push 'guide' to start the calibation- then it automatically kicks in-- another question here though- while its calibrating- do you lose your alignment?

[Dennis]

I would hazard a guess that when calibrating, with PHD electronically “pressing” the RA+ RA- Dec+ and Dec- motor movement buttons, it should be no different to the operator manually pressing the buttons on the hand controller, so the telescope pointing system should “remember” where it is as I assume it receives positional information feedback from the encoders?

I only lose positional information and void the pointing alignment if I manually undo the clutches on my Vixen and Tak mounts and move the scope.

Cheers

Dennis

[g__day]

I use this combination absolutely fine, so it is completely possible.

I custom made the cable according to the Celestron and SBIG 4 cabling connections. From memory it goes into a shoestring parallel port connector (wish I had of got a Shoestring USB connector - that automatically starts with all 4 directions powered down, the parallel port's start-up is random so I write a script to copy a binary file I created null.bin containing only a HEX 0 to my parallel port - this clears all port settings).

Next in the Control Panel -> System -> Device manager -> Ports -> Parallel Port -> Resources setting I check what I/O range is being used. Say its 0378, you have to check that this same I/O address is set under the PHD mounts tab - else all fails.

I guide using a DSI. I make sure its orientated so the usb cable from the DSI points downwards at the centre of the eyepiece or camera hanging from my larger SCT (the 80mm Meg I use rests atop the 9.25 Celestron). The key thing is you want your X / Y axes to track the mounts axes as well as you can so corrections are only on one co-ordinate grid at a time.

Then I simple slew to a bright star and focus the DSI running PHD in capture mode, and focus on this bright star as best I can.

Then I stop capture - you apparently have to press stop or it won't guide when you click on guide - it wook me a month to learn this! I click on the brain and make sure guide on both axes is set to auto and that force calibration is set on.

Now you are ready to calibrate. I set steps to be say 0.5 secs on a bright star. Simply click on the star you wish - wait a second or two for the green box to form around it and check its X and Y pixel coordinates stay stable after a second or two. Then press Guide and watch how it tracks E - W, clears backlash then tracks N-S.

It should say calibrated at track well!

About 1 in 3 times this fails for me and if I just try again (press stop, click on brain forcing calibration for both axes again, slect your star than click on guide again) it succeeds.

Note that if I slew more than 45 degrees I generally re-calibrate PHD.

Now once it says guiding I generally lower the refresh rate to 3-5 seconds, so it doesn't get too twichy and over correct.

Doing this on a fairly well aligned and balanced mount seems to work fine for me. Hope this helps!

[seeker372011]

wow thanks for that..a lot to digest and check out

Thing is, I use a usb cable plugged into the handset-as opposed to the shoestring adapter..and maybe that is my problem..it merits a lot more investigation ..but thanks again for the tips

[g__day]

Perhaps write down in detail what steps you follow, and we might spot where things are going wrong!

[seeker372011]

yes I'll do that the next time I take the mount out

[DobDobDob]

Why don't you do that next Sunday night :D

[Harpspitfire]

well, i use the handset myself- 1st time trying to autoguide i got it all working, calibrated, and tracking the guidestar- (test only)- my 1st attempt at imaging was complete failure, i had computer freezes and USB overloads- PLUS i lost the mount go-to, since then i havent had a chance to figure out the problem- i 'might' have to get the USB shoestring adaptor, but with PHD its supposedly able to work with just the handset- so until then, i have to wait and see if its user error or equipment error, hopefully it was just user error since the shoesting adaptor is rather costly