Guiding worse than tracking with mount - what's wrong ?

[jbdave (David)]

Ok, I have no idea what's going on but I've never come across this before.

I set up my laptop, connected the guide camera like I normally do and started guiding. The problem is that when guiding was on, star trails went crazy. I turned it off and the mount's tracking did a much better effort.


I've used the guide camera plenty of times, and the settings looked ok, but no matter what I tried I couldn't get it to guide for me - it's like the guide camera told the mount to stop tracking at all, rather than assist it.

[gregbradley]

Originally Posted by jbdave

Ok, I have no idea what's going on but I've never come across this before.

I set up my laptop, connected the guide camera like I normally do and started guiding. The problem is that when guiding was on, star trails went crazy. I turned it off and the mount's tracking did a much better effort.


I've used the guide camera plenty of times, and the settings looked ok, but no matter what I tried I couldn't get it to guide for me - it's like the guide camera told the mount to stop tracking at all, rather than assist it.

More detail about your equipment and setup would help here. Which software and guidescope/guide camera.


A few things that can make guiding can wild:


1. You've calibrated for one side of the meridian and now you are on the other side and your software does automatically reverse the commands so the commands are reversed.


2. You have a brighter star intruding into the frame of the guide camera and the guider is using it instead of the guide star.


3. The camera has some hot pixels in the guide frame that the software is taking over the guide star. If you click on auto find guide star you can see what the software is picking. A lot of guide cameras don't have a shutter so auto darks are very difficult.

4. Similar to #3 the guide camera may have artifacts/interference that is creating bright pixels that the software is picking.

5. Your software's autoguiding settings are incorrect, wrong type of guide signals being sent ie. direct guide on a mount that does not take that.

6. A bad cable.

Greg.

[Stefan Buda]

Originally Posted by jbdave

Ok, I have no idea what's going on but I've never come across this before.

I set up my laptop, connected the guide camera like I normally do and started guiding. The problem is that when guiding was on, star trails went crazy. I turned it off and the mount's tracking did a much better effort.


I've used the guide camera plenty of times, and the settings looked ok, but no matter what I tried I couldn't get it to guide for me - it's like the guide camera told the mount to stop tracking at all, rather than assist it.

Sounds exactly like what happened to me Sunday night. I wasted hours trying to get my guiding to behave, and in the end changing the cable between the QHY5 and the EQ6 mount did the trick. I still don't understand how a cable can generate periodic error, but it is what it looked like. Every minute or so the RA tracking would deviate, then catch up. Tried every trick in the book, without success, until I changed the cable.

[jbdave (David)]

I was using a Orion starshoot autoguider on an EQ6 (direct connection) using PHD2.
I have done this before previously without problems.

I unplugged the (ST4?) cable and turned it around to check. Same issues.
Could it be faulty ?

[gregbradley]

Its been a while since I used PHD2 but isn't there a menu box about what type of signal goes to the mount? Like direct guide, pulse guide, camera relays.

Perhaps you have accidentally changed one of those settings.

Just a thought, probably unlikely but who knows.

If its any comfort it often blows me away that even if you have an observatory and the same setup night after night how something can fail to connect or need some attention.

Its hard to keep an observatory in an unchanging static state.

Greg.