Anybody having PHD guiding problems?

Geoff45 (Geoff) · #1 23-10-2009, 01:21 PM

Has anybody had guiding problems which seem to have developed out of nowhere. Typical is smooth guiding in dec with a sudden spike and then with an overshoot to correct, after which things settle again. The RA usually follows the dec with spikes. Sometimes the guiding is perfect for a long period, then suddenly goes off.

There is a long thread on the Stark labs Yahoo! site http://tech.groups.yahoo.com/group/stark-labs-astronomy-software/message/17531 about this problem. There seems to be a developing perception that somehow the latest versions of PHD have a bug, which is not removed by returning to an earlier version.

Has anyone noticed this, or is the whole thing just due to a bunch of individual problems which everybody is attributing to the same cause?
Geoff

Gama · #2 23-10-2009, 04:38 PM

Have you tried an earlier version ?, quickest way to find out if its soft or hard ware..

Theo

Geoff45 (Geoff) · #3 23-10-2009, 05:21 PM

Quote:

Originally Posted by Gama

Have you tried an earlier version ?, quickest way to find out if its soft or hard ware..

Theo

Yes, but as I noted above, the later versions (so the theory goes) affects the system in such a way that going back to an earlier version doesn't help.

mill (Martin) · #4 23-10-2009, 06:32 PM

I have the latest phd guiding with eqmod and it works perfect.
I had the same problem as you and i just wiped the lappy and reinstalled windows and put on all the newest stuff,voila the problems are gone

jjjnettie (Jeanette) · #5 23-10-2009, 06:46 PM

Do you run a registry cleaner after deleting?
You don't want to leave a skerrick of the program behind.

Moon (James) · #6 24-10-2009, 11:51 AM

Mine has been playing up recently. I tried rolling back the software but it didn't help me.
It could very well be individual problems... who knows. I've wasted a lot of time trying to fix this problem.

DeanoNZL (Adrian) · #7 24-10-2009, 01:41 PM

I was having very egg shaped stars in RA that I couldn't fix. 2 minute subs max.
Went as far back as ver 1.8 with small improvments.
With all the cloud recently, I pulled the EQ6 apart and checked & adjusted all the gear mesh. Last night was the first night back up, and now getting 15 minute subs. Just in time for the moon!!!!!

MrB (Simon) · #8 24-10-2009, 01:58 PM

Quote:

Originally Posted by ghsmith45

Yes, but as I noted above, the later versions (so the theory goes) affects the system in such a way that going back to an earlier version doesn't help.

Sounds like a file or registry entry is not being un-installed.
I used to use a program that monitored every change made to the system by an installed program, every file and its location was logged, every registry entry change, etc.
You could also use it when un-installing a program and compare the results, then go back and manually clean out anything left behind.
It was called InCtrl5, a great program but I don't think it works with XP/Vista/7.
Pretty sure there would be something similar around though

leon · #9 24-10-2009, 07:51 PM

Yep I have had dose exact problems of late, it has performed perfect for ever, but the last two image runs have been exactly has described in this first post.

Leon

telemarker (Keith) · #10 25-10-2009, 02:25 AM

I've had these sort of problems for a while now, with Dec jumping around all over the place. I have taken the dec motors off and adusted the worm gear so many times but it was having no effect. Constantly rebalancing the scopes also did nothing. Tonight though after reading this thread I uninstalled PHD then ran a registry cleaner, reinstalled the latest PHD and now it's guiding like a charm, best graph in yonks. Thanks peoples.

Keith

g__day (Matthew) · #11 25-10-2009, 11:36 AM

I've seen a tad more jumping in DEC - its around +/- 2 arc seconds usually - so only on careful inspection of a fine structure shot do you realise you've lost fine detail that a few nights earlier you nailed.

multiweb (Marc) · #12 25-10-2009, 03:35 PM

IMHO PHD works quite fine. The latest releases (1.10 and onwards) do work a bit differently, the maximum DEC duration being one of the initial changes that threw a lot of people off initially because PHD is not chasing DEC drift as hard as it was back then. Its guiding aggressiveness in RA has also been increased so you'll have to tweak that down to maybe 50-60% in the brains settings to avoid jumps. Having said that I haven't experienced any major drama with the new versions. There is no such things as PHD induced "gremlins" in the registry or on your computer OS. This to me starts sounding like a witch hunt. "My car battery's flat! Bloody PHD's at it again"

. If you have big jumps in RA or DEC you have bigger problems than the software. Try to do unguided for a while, iron out any mechanical/balance issues then reactivate the guide output. Realisticaly speaking if you're guiding through clouds and lose the guide star for 30s or so then you should pick it up again no problem without any noticeable drift. If that's not the case then you have bigger problems (why do I keep repeating this?

).

Moon (James) · #13 27-10-2009, 09:44 PM

In my case the problems were caused by:
1. Incorrect brain settings after the PHD software upgrade (along the lines suggested by Marc)
2. I changed to OAG and therefore a longer focal length. Again the brain settings needed to be updated.

When I had the incorrect settings I was seeing some very weird behaviour (refer attached - image scale 0.66 arc sec / pixel)

With the new settings, the problems have gone away. One key change was to reduce the calibration step size - the calibration was happening too quickly and this is what caused the random results after each calibration.