PHD2/Mount Gremlins

[MakkaPakka (Daniel)]

Hi All,
I'm just about at my wit's end regarding this issue, so any assistance or insight would be super helpful at this point. �� I've been using this exact equipment for months with no issues, using the same software versions for PHD2, etc.


Here's the scenario:
I set up my equipment, balanced, loaded up my laptop with PHD2, slew to my target for the night, and began PHD2 calibration. PHD2 then throws an error: "RA and DEC are at questionable angles" or "PHD2 is unable to make sufficient corrections," etc.


After Re-setting up my equipment, balancing, arranging cables, etc, and loading up my laptop with PHD2, slewing back to my target and begin the PHD2 calibration. I encounter the same errors. Even after powering off the mount and attempting a PHD2 calibration again.


At this stage, I decided to re-install PHD2 and setup the software from scratch. While there was some progress, it would keep failing the calibration (PHD2 would report "Star Lost" every time) when doing the north adjustments. I also noticed when performing a drift align, the RA (Blue line) would not show, only the DEC (Red line)


I setup everything a third time, re-installed etc and this time PHD2 would just let the star I was calibrating on drift away, despite EQmod allowing me to slew on all axis.


I then pulled out another device, which I've used with this equipment previously, and did the routine from scratch, only to find the same issue.


Equipment details:
Mount: Skywatcher EQ6-r Pro
Guide Camera: ZWO 120mm
Connection: USB for both.


Here are the logs I captured: https://drive.google.com/drive/folde...64?usp=sharing


Thank you for the assistance! It's strange because literally weeks before, I had it all set up and working brilliantly, taking 3-minute subs and tracking like a dream.

[Startrek (Martin)]

Sounds like a typical calibration issue
You don’t slew to your target and then calibrate as your target every session could be located in a different part of the sky and not at Dec= 0
Calibration should be done close the meridian (N) on the celestial equator at Dec=0 or as close as possible
If you want you can down load the latest version of PHD2 , use the installation wizard , use the calibration assistant
If you want to keep using an older version of PHD2 which doesn’t have the calibration assistant make sure you calibrate in the location as above
Make sure your guide scope and camera are focused
Use Ascom pulse guiding ( guide camera cabled direct to laptop ) not the old ST4 way where camera is connected to mount first then mount to laptop
Also once you get a good calibration you can save it for months and months ( provided you don’t move the guide camera and guide scope on the OTA ) I’ve used the same calibration for over a year with no issues.
Polar alignment is important too , make sure your polar aligned to a few arc mins ( from memory PHD2 will be ok up to an error of 10 arc mins but I wouldn’t recommend that sort of error )
Im usually around an arc min which is fine. Folk spend time on PA to get down to 0.4 or 0.5 arc min but it’s not required.
I noticed your using EQMOD, make sure you use the PH2 settings in EQMOD ( see attached )
There’s many other items to check but start with all the above first

Good luck
Martin

[Leo.G (Leo)]

This may sound like the STUPIDEST answer you'll see.
I recently had an issue finding the moon with my GOTO mount. I parked the mount 3 times and powered down, started it up again and same thing, over and over.


SOME IDIOT still kept punching in the date as January 2023, I forgot to change the year....
It happens (I think)?

[MakkaPakka (Daniel)]

Originally Posted by Leo.G

This may sound like the STUPIDEST answer you'll see.
I recently had an issue finding the moon with my GOTO mount. I parked the mount 3 times and powered down, started it up again and same thing, over and over.


SOME IDIOT still kept punching in the date as January 2023, I forgot to change the year....
It happens (I think)?

Hahaha, I've been there too! I've set the dates wrong and spent hours figuring it out.. It was only until I was about to pack up when I checked the time and it clicked.

It's often the simple things that cause the most annoying of issues.

[MakkaPakka (Daniel)]

Use Ascom pulse guiding ( guide camera cabled direct to laptop ) not the old ST4 way where camera is connected to mount first then mount to laptop

Yea I've seen many online say Pulse is the way to go, my ZWO 120mm is connected via USB-C and pulse guiding (So far I've only pushed upto 5min subs when it's all working

Also once you get a good calibration you can save it for months and months ( provided you don’t move the guide camera and guide scope on the OTA ) I’ve used the same calibration for over a year with no issues.

Ahh fair enough! I've got in the habit of redoing it every time, because my location has the poles blocked visibly, so I drift align every time via the PHD2 tool (I try to get it around 3 arc secs or under every time) and then sometimes during my imaging sessions it drops off tracking the DEC, re-calibrating keeps it happy and running.

[Startrek (Martin)]

Do you realise your EQ6-R pro mount comes with an excellent polar alignment procedure in the Synscan handcontroller which doesn’t require a view of the pole
I’ve tried the PHD2 drift align tool and found it a bit time consuming and fiddly

Attached is the procedure for Synscan polar alignment using your handcontroller and live view function with crosshair with your capture software on the laptop screen.

I can be polar aligned to around 1arc min with about 3 or 4 iterations in 10 mins

Cheers
Martin

[ChrisV (Chris)]

What Martin said. You don't calibrate phd2 at any old place in the sky. Point up near meridian. Or preferably download latest version and use calibration assistant - it will slew to a good spot them calibrate.

[Startrek (Martin)]

Originally Posted by ChrisV

What Martin said. You don't calibrate phd2 at any old place in the sky. Point up near meridian. Or preferably download latest version and use calibration assistant - it will slew to a good spot them calibrate.

Thanks Chris,
Yep , the amount of folk I read on the PHD2 forum each week that have issues with getting their guiding to work are mainly due to -

1/ Not using the Installation Wizard to set up everything in the first place ( common mistake is using the main scopes focal length instead of the guide scopes focal length amongst many others

2/ Trying to calibrate in the wrong part of the sky ( that’s why Bruce set up the Calibration Tool in the latest version. The only problem is that you can’t access the Calibration Tool through an imaging software, you have go direct to PHD2 to access and use it.

3/ Bad guide camera focus and using a colour camera in lieu of a mono camera

4/ Fiddling with all the settings ( defaults usually get you up and running)

5/ Dec / Ra Balancing issues and mechanical issues ( huge backlash on cheaper mounts )

6/ Accessing PHD2 through their imaging software and the imaging software is not set up correctly for PHD2 in relation to version bugs , driver issues , operating platform system issues. ( eg: EQMOD PHD2 settings)

7/ Using the old ST4 connection system instead of Ascom pulse guiding connection

And a host of other issues

Cheers
Martin

[leon]

PHD1 was a dream when I used it, forget about PHD2, Just my Two cents worth

Leon

[Startrek (Martin)]

Originally Posted by leon

PHD1 was a dream when I used it, forget about PHD2, Just my Two cents worth

Leon

Give PHD2 a go , you’ll be pleasantly surprised
It’s developed from the early days of PHD1 to a solid reliable open sourced guiding program, especially Multistar guiding , the Installation Wizard and Calibration Tool
Most of the problems we see are self induced Cockpit errors by the user ( not the software itself )
Demands for better guiding have increased due to higher expectations, but there’s one thing you can’t fix and that’s Mother Nature ( atmosphere stability) and a crappy mount !!
Cheers
Martin