Astrophysics GTO900 mount and PHD issue

[tooth_dr]

I’ve been helping a friend setup his autoguider, and it did work the first night he tried it. But ever since he can’t get it to calibrate with with version of PHD.

The stars start to move when calibration begins, and then just keep moving out of the green box, almost like sidereal tracking is switched off. 

Any ideas?

[tooth_dr]

Should have added that the laptop crashed after first night of it working, so he has to reinstall all the software again. 

[michael8554]

Find the PhD guide log and  the debug log on the pc and post your problem and files on the PhD forum.

https://groups.google.com/forum/m/#!forum/open-phd-guiding.

The authors will find the problem from the logs.

Michael 

[tooth_dr]

Logs attached.

 

PHD_log_31Dec17.txt

PHD_scope_ascom.log

[michael8554]

The log appears to be from PHD  version 1, PHD2  is currently version 2.6.4, suggest you upgrade !

Michael 

[tooth_dr]

6 hours ago, michael8554 said:

The log appears to be from PHD  version 1, PHD2  is currently version 2.6.4, suggest you upgrade !

Michael 

Michael it happens with both so the problem isn’t version related. Plus the DMK21 camera doesn’t work with PHD2 in LX mode. I’ve ask my friend to run PHD2 and send over the files.

Can you help with the current log files posted?

[kens]

Unfortunately not. The old version of PHD did not record much in the log so it isn't very useful.

Have you tried the WDM driver with the DMK?

[tooth_dr]

40 minutes ago, kens said:

Unfortunately not. The old version of PHD did not record much in the log so it isn't very useful.

Have you tried the WDM driver with the DMK?

Yes he has tried that with the WDM and it works just not proper long exposures (or at least not easy to achieve)

I have asked him if he will do a PHD2 log tonight if it is clear.

thanks for your help  

 

[tooth_dr]

57 minutes ago, kens said:

Unfortunately not. The old version of PHD did not record much in the log so it isn't very useful.

Have you tried the WDM driver with the DMK?

 

Hi Ken

 

He just forwarded me some PHD2 logs from last night

 

Thanks for your assistance.

 

Adam.

 

PHD2_DebugLog_2017-12-11_215202.txt

PHD2_DebugLog_2017-12-11_215408.txt

PHD2_DebugLog_2017-12-28_204622.txt

PHD2_DebugLog_2017-12-31_231143.txt

PHD2_GuideLog_2017-12-28_204622.txt

PHD2_GuideLog_2018-01-01_001111.txt

[kens]

My first guess is that the mount has been configured for the wrong hemisphere as its westward moves are at around 2x sidereal.

I'm assuming the guiding focal length is correct at 540mm.

[tooth_dr]

33 minutes ago, kens said:

My first guess is that the mount has been configured for the wrong hemisphere as its westward moves are at around 2x sidereal.

I'm assuming the guiding focal length is correct at 540mm.

Yes he is guiding with a TeleVue TV-NP101 scope.

I’ll pass on the message. He does take unguided images quite frequently, would it be possible to have it set wrong and still take those images?

[kens]

Actually - that guess doesn't make any sense or you wouldn't get a stable image to guide on.

Whats interesting is that there is very oconsistently a small step west  of around 5" followed by two large ones of about 30".  That indicates backlash in RA so the first thing is to check that any backlash is taken up before starting to calibrate. This is done by making the last move westward.

If the large steps are sans backlash then the calibration step size is much too big and should be more like 100ms. That would in turn indicate that the guide rate entered into the calculator was too large. If it was read from the mount then the mount supplied the wrong value. This is not unheard of so worth checking.

I would recommend at this stage to  start with a star cross test (from the tools menu) to get an idea of how the mount is responding to guide commands.

[tooth_dr]

Thanks @kens

I’ve forwarded this to him. 

 

Regards

Adam. 

[1parsec]

I would turn off PEC correction via the GTO controller too while you're testing this out.  I had a 'funny' blip on my mount and the PEC wasn't ok and needed to re-record it.

Also do a DEC-RA test run just to make sure backlash isn't an issue.  Ray Gralaks Pulse Guide  http://www.pulseguide.com/index.html   can run this test and give a visual of the backlash performance
Good results look like this  https://www.cloudynights.com/topic/483600-ap900-dec-backlash/ 

If backlash is detected check according to this pdf - http://www.astro-physics.com/tech_support/mounts/backlash2.pdf

 

 

 

[tooth_dr]

3 hours ago, 1parsec said:

I would turn off PEC correction via the GTO controller too while you're testing this out.  I had a 'funny' blip on my mount and the PEC wasn't ok and needed to re-record it.

Also do a DEC-RA test run just to make sure backlash isn't an issue.  Ray Gralaks Pulse Guide  http://www.pulseguide.com/index.html   can run this test and give a visual of the backlash performance
Good results look like this  https://www.cloudynights.com/topic/483600-ap900-dec-backlash/ 

If backlash is detected check according to this pdf - http://www.astro-physics.com/tech_support/mounts/backlash2.pdf

 

 

 

Thanks Dave, forwarded to the interested party.

 

Regards

Adam

[tooth_dr]

Thanks for everyone’s input.

Issue resolved:

“Issue was the controller setting in the ASCOM driver - it was set as a CP4 controller instead of a CP2”