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Guiding problems

Started by Carole, Oct 26, 2010, 11:49:14

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Carole

QuoteSounds like cables to me?
Starting to think that Chris.  
I have had an even worse problem tonight as it wouldn't even calibrate.  It first of all said there was a Dec calibration failure, and then it said there was an RA calibration failure because the star did not move enough.
So...........for the purpose of exclusion I tried my other laptop.  After trying a number of ports it could not find the GPUSB, so I removed the USB extension lead and used it directly from the shorter GPUSB cable and it recognised it that time.  This time it calibrated but then started to have the same problems as last night - kept losing the star.

So I think that's eliminated the software and the laptop.  
I will try my other mount next time I am out and if it happens with that too it can't co-incidentally be both mounts, it must be the cables.  

The joys of imaging.  Yes Fay I know "you warn me".

I only bought these cables less than a year ago which is annoying but cheaper than a duff mount.  

Carole

MarkS

Carole,

I've occasionally had a similar problem with PhD.  In my case, closing PhD and then restarting it always does the trick.

Also, you need to check if the star actually does move during calibration.  Watch the calibration take place becuase it helps diagnose what may be happening - does the star move? - does the GPUSB LED flicker?  In my case the star didn't move and that's why the calibration failed.  After restarting PhD it worked just fine.

Mark

Carole

QuoteIn my case, closing PhD and then restarting it always does the trick.
No, I tried that, and the calibration is only a new part of the problem.  
Also I have tried two different laptops.  

The star definitley moved when it calibrated on the 2nd laptop (XP) as I watched that (at one point it said it was sorting something out on backlash so don't know if that's clue but still managed to calibrate.  
I can't be sure about the calibration on the 1st laptop (Vista) which I did last night.  However it still lost the guide star consistently on both laptops and on the Vista it wouldn't calibrate tonight but it did last night.  
Quotedoes the GPUSB LED flicker?
Yes I checked that on the 2nd laptop (XP) and it was flickering. 

I always try restarting things if they don't work but it made no difference.  

Thanks anyway, I think it's a process of elimination.

Carole

MarkS


Calculating backlash is a normal part of the calibration procedure - if you watch the calibration in progress you will see it come up every time.  You really must watch the calibration take place because then you can begin to gain experience of what a successful calibration process looks like and then what is different about a failed one.

If you keep losing your guidestar then find a brighter guidestar by adjusting the guidescope rings.  Or increase the exposure time (on the dropdown box) - you can increase it to a few seconds but note that this will also slow down the calibration process significantly.  Losing the guidestar (low SNR) is another reason for failure to calibrate.  When you click on a star, its SNR appears in the status bar - I would choose a star with a SNR of at least 5.  Increasing the exposure time will increase the SNR of the stars.

Mark

The Thing

Carole,
Whenever I've had the ' not enough movement' message its always been cables. I'm discounting Meade specific issues to do with the hand controller.

Duncan

Carole

QuoteOr increase the exposure time (on the dropdown box) - you can increase it to a few seconds but note that this will also slow down the calibration process significantly.

Did that too and noticed the calibration time increased.

QuoteWhenever I've had the ' not enough movement' message its always been cables. I'm discounting Meade specific issues to do with the hand controller.
Hmmm does the handcontroller have something to do with guiding?  I wouldn't have thought of that as once you've slewed to your object you don't need to touch it any more, but that it worth thinking about if it does as I had some problems with this hand controller cutting out once before and decided it was loss of power, and now seems to be OK.

Well I guess I'll get to the bottom of it eventually, it's useful having two mounts now as at least I can interchange things and eliminate the culprit, but I don't have two sets of cables.  Does any-one have a set I could borrow if need be (are they the same for all mounts?) I use a GPUSB and an RJ12 cable.

Carole



Carole

#21
I'm still working my way through eliminating things to do with guiding but having a night with stars on a night when I am at home is holding me up.

So far I think I have eliminated the cables as I tried the manual NSEW pad within PHD and watched the LED light in the GPUSB and it definitely flickered red and green.  I then listened to the sounds of the mount change as I did it which was quite difficult as it is so faint.  The East and West I could definitely hear a change in sound, but not so clear on NS.  However at this stage my handset cut out and (this is the second time this has happened).  So I changed to the handset on my spare mount and I again could definitely hear the East and West sound changes on the mount and I am fairly certain I heard them on North and South although it was VERY faint.  

So it looks like the signals are getting through OK.  

So what else is there to eliminate:

Having tried two different laptops when all this happened I think discounts the laptops and the PHD software as I got the same problem on both.

Some-one has suggested to me that it could be the network on the laptop that is causing a conflict and causing the signal to drop.  I have both 02 (for a dongle) and the Observatory network set up on the laptops.  Although the O2 is not being used at the time, is there any possibility that this might be causing some sort of a conflict ?  Even if I am not actually using them at the time.  My problems seem to have started around the time of putting these networks on.  

Also this handset that has cut out twice.  Would a handset have anything to do with guiding problems?
I am thinking to uninstall the networks just to see whether it makes any difference.  

Carole


mickw

You are not testing laptops, software, or cables  - you are testing laptops with all sorts of poop plugged in including a problematic handset.

Unplug everything, including the possibly duff handset and test everything with ONLY a laptop and a handset you know works.
Otherwise you'll be stuck knowing the problem could be either -

Laptop
Cables
Software
Dongle
Network
Handset

If it works with everything unplugged, plug things in one at a time and test again - When it stops working, unplug the last thing and test again, if it works don't plug the offending item in again.
Growing Old is mandatory - Growing Up is optional

Carole

Guiding won't work unless most of those things are plugged in, that's why I am trying to eliminate things one at a time.

I am just asking whether a network (switched on or not) can cause a conflict?  I don't want to have to uninstall unless really necessary. 

I can easily eliminate the dodgy handset. 

As I said
QuoteSome-one has suggested to me that it could be the network on the laptop that is causing a conflict and causing the signal to drop.
, but this is some-one who knows about PCs but has never done guiding.

Carole

mickw

I meant don't plug in things you don't need

Network - no
Dongle - no
Suspect handset - no
Growing Old is mandatory - Growing Up is optional

Mac

having a network plugged in wont make the blindest bit of difference to your guiding.

Although if you notice your router moving across the table i;d suspect something is defiantly wrong.

As i've said before, plug every piece of your equipment one by one into every usb port, and install the drivers each time.

When that is finished, reboot your pc and then plug in the equipment you need,
Which should be guide camera and mount cable.

I would do the following.
Start the software you use to image with, and check you are getting an image. If yes, then your camera and cable is ok.

Close the software down

Start the software you use to controll the mount, connect to the mount and use the software to move the mount.
If this works then the software and the cables and the mount are working ok.

close this down.

you know now that the cables, mount and camera are all ok.

start your guiding software and go through the motions.
if it dosent work, then either the software is corrupt, (unlightly, but not impossible) or some of the settings are incorrect.
As said before, start with the exposure of the star, make it longer and then see what happens.

If its still not working reset the guiding software to the default settings and start again.

Mac.

now, start the guiding program.

Fay

I often have times when the calibration fails because of the star not moving enough. I have to go to another part of the sky, well away from north, & find another one, then go back to where I want to image & it then it guides ok on whatever star I select, even though I have calibrated in a different part of the sky. 
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

Carole

Mac I have already done what you suggested but have not found any problems except that guiding is not working properly when I try to guide on a star which is why I am searching for a less likely cause.

Fay that is worth thinking about as the last time I was trying to guide I was doing M81/M82 and of course that is close to the North pole.  However the problems started when I was doing NGC7000 which isn't.

Carole



mickw

OK, now I understand what the difficulties are.

My first attempt at the G word was not good -
Forgot to turn EQAscom on
Forgot to focus guide scope
Forgot to carry out alignment
Forgot to turn PHD Guiding on/start
Forgot that when you change orientation of camera, need to refocus

I'll reassemble everything indoors and Make a List

Running before walking springs to mind  :oops:
Growing Old is mandatory - Growing Up is optional

Fay

A little bird is reminding me that you never ;) read instructions.....................
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!