Meade LX90 Alignment Issue

[Wanga]

Hiya folks,

My first post here (have been a lurker and active on the Facebook page).

After reading many posts here, I recently bought a second hand LX90 UHTC. It's about 10 years old and needed a good clean (the former owner was a heavy smoker) and was very dusty and a little sticky. Anyway, it cleaned up nicely, came with heaps of accessories and after a few nights of viewing is proving to have lovely optics. I purchased a camera adapter (have been getting some great preliminary results)0, a power tank and some other bits and bobs.

Anyway, here's the issue: at first I had some trouble aligning, but got fairly close to what I thought was a good alignment for an old scope/new user. It came with an equatorial wedge, but I could not get anything to align... too much to deal with at this early stage... so I went back to Alt/Az to get my head around the scope.

Because the scope had a few degrees of misalignment with stars, DSOs, and a great degree of error for planets, I decided to upgrade the Autostar

I decided to update the Autostar software to the latest version (6.0) on January 31. After a few fruitless tries at aligning with the new version (correct location/time/date/daylight savings) the scope suddenly aligned perfectly with a two star alignment and worked beautifully all night. I saw my first EVER external galaxies (Sculptor and a few others) and was very excited.

So last night (Feb 1) I had another session - but the scope would not align... not even close. I used Sirius/Canopus as my align stars, and tried a few others as well. However, the scope was about 25 degrees south east incorrect, and no matter what I did (reset, re-input all site location data etc about a dozen times) the scope continued to point to a totally obscure place south east of my alignment stars.

So... I changed the date back to Jan 31 - and behold, it almost aligned, give or take the distance/time difference. I changed back to Feb 1 and it would not align.

Weird, right? :sadeyes:

So, does anyone else have this problem, or know of it... or have heard of a solution? I'm baffled. I managed to get some nice images but slewing was out enough for me to have to keep the exposures very short and I was unable to pinpoint any faint DSOs.

Any thoughts? :)

Look forward to having a chat if anyone is up for it.

Cheers

Wanga (near Warragul, Victoria).

[jamiep]

might sound like a dopey suggestion - but are you using 2013 as the year (a mistake I've been known to make in the first month of a new year)? Do you have the GMT offset correct for daylight savings (can't remember the format for the Autostar) but you need to have time date and approx alignment correct and it should be close on initial?

Also re-check your long/lat settings making sure its in the southern hemisphere ...

[acropolite]

As Jamie said, check your Lat/Long, check that you're set to Alt Az mode, make sure your time & date are correct make sure you are pointed North (compass bearings can be out and don't forget to compensate for magnetic variation when working out true north). If you get the chance use the Solar Noon (http://www.iceinspace.com.au/forum/showthread.php?t=5690&highlight=solar+Noon) method to calculate true north. I always set Eastern Standard time and don't switch daylight saving on, causes less confusion.

If the LX has LNT, ignore the automated setup, manually level and set north and just do the 2 star alingment. Autostar software has always been buggy, I remember one build I used would go pear shaped if you entered a custom location, if you suspect that it's a bug issue go back a version or two.

[Wanga]

Thanks for getting back to me about this guys... :)

I've gone back and checked everything you've suggested to see if I missed anything (my heart skipped a beat when you mentioned the year - but I at least had it right!)

-Correct long/Lat for my exact location in my site options.
-I'm pointed true north. I spent a good deal of time a few years back to ensure I had a correct bearing, so I'm confident that this is okay.
- I have daylight savings switched to 'yes' and my GMT is set to +11 in 'site' settings.
I might try and change it to 'no' with a +10. However, I did mess around with the +10/+11 settings last night, without changing the actual real DLS time on the Autostar.

It's kind of odd that it works for 31/01/14 but not for 01/02/14. Maybe it is a bug?

If I load up an older verion of the software, I wonder if it overwrites the new version or if I should remove it first. I'll have to look into it.

Let's see how it goes. :shrug:

Thanks again!

Wanga

[netwolf]

Edit: if DST yes then gmt should be 10 I think not 11.

I just got a used lx90 and had similar issues at the start. But now it has been working well for past few nights.

1. Updated using starpatch modified firmware.
2. Took it to Bintel for a tune up on the dec as min had a bit of play plus optics cleaned. Very helpful and professional guys.
2. Most critical spend more time leveling the scope, I have a level ruler so I also do a 360 turn to ensure its level in all directions. You could get a bulls eye level or use a android or iphone app for this also, but more expensive if you drop them.

3. Removed the lnt and don't use automatic align.
4. Make sure your finder scope is well aligned.

5. As Phil mentioned use the solar noon method to locate true north, for me this line is almost parallel to the back wall of my house.

Last night I was moving from north to South and hitting all my targets now and then I would recenter and sync on the target (hold down the enter key for 1sec and let it go centre and hit enter again).
I used Procyon and Betelgeuse for a two star alignment, then go to Jupiter and sync on that also. This worked on Thursday and Saturday night.

My dec still has some play but I don't as yet have counterweights so that could be it.


Hang in there. Keep trying. Even though I owned a lx90 some years ago I still was getting problems and frustrated. But keep trying and it will work out. Else reach out to your local astro clubs and try to attend a session with them.

[AndrewJ]

Gday Wanga



That is the ASU version, not the Hbx firmware.
You should have something like 43Eg, 5CE1 or A1F7



That should be +10 for the site offset and DST = YES
The site offset should be the std offset for the site, irrespective of DST.



They may actually be a bit too high in elevation for a good align ( depending on time ). I normally try to find stars that are about 90 deg apart in Az and are each about 35 to 55deg in elevation. The higher the stars elevation, the worse the possible error in Az can be when centring.
To really test 2 star aligning well, if you can see the pole,
use Canopus and Acrux mid evening. This pair normally gives very good and repeatable results. At least it will show how repeatable the 2 star is.


Andrew

[acropolite]

That's the very reason I always use standard time and no to DST.

[Wanga]

Thanks for the advice everyone, I appreciate it... I will have a crack tomorrow evening. We have thick cloud right now.
I'll keep you informed.

[aarong]

I have a similar aged lx90 too. Leveling the tripod and pointing it north does help. If put back on the wedge, levelling and a reasonable polar alignment is needed. It's more forgiving in alt/az.

+ 1 for Andrew's advice. Installing the patched firmware version with starpatch will help iron out the bugs and give you more functionality.

You can also recalibrate the sensors, if the other suggestions don't work, but I think they will. Also check out Weasner's Meade site (http://www.weasner.com/etx/techtips/etx_tuneup1.html). There are 3 parts to tune up your scope. I have done part 2 and 3 and it helped improve goto performance and reduce backlash.

If all else fails, then Bintel can service the scope for a very reasonable price. They can also up-grade the firmware for you or give you advice on how to do it, if need be.

[Eggmoon]

I have a newer LX90, only a year and a half old, and don't seem to be having any alignment problems... apart from not being to polar align very well... but pretty sure that's me, not the scope! Level the tripod... then level it again when you load the scope... then level it again before you turn it on... can't get it too level.

Mine has the GPS unit on it... so I don't need to worry about Lat / Long and setting the time, the lovely satellites help me out on that.

Hang in there... so much enjoyment when you get it working... and you must have some nice dark skies out where you are compared to me in the suburbs!