Unpark problem with 10" LX200R

[Mel]

Hi all,

I am an owner of a 10" LX200R - have had it for about 2 years now. It's on a wedge/pier permanently mounted. I have accurately polar aligned and the pointing is now excellent - whereas it wasn't previously .

One problem that keeps recurring however is when coming out of park (I use a custom park position, pointing south, horizontal tube) after parking an accurately-aligned session, when asked to GOTO a star, it takes a GPS fix, then proceeds to slew to a number of hours (haven't measured exactly how many but I would guess 6-8) in RA too far round - i.e. East). If I then realign it to the star and SYNC, all is well.

Bit of a niggling point, but it would be good to solve this. I've checked the obvious things - UTC offset being the first one to come to mind - do I need to 'Calibrate Sensors' - I thought that was just for AltAz set up?. The offset is set to 0 which I think is right for the UK.

Any ideas anyone?

Iain

[barkis]

I don't suppose having cord wrap on, or slew limitations set, would have any effect on the problem. It seems a silly suggestion I know, But will keep thinking about it.

Ron.

[Mel]

I am careful about any cord wraps/snags and usually sort the scope out cable-wise before I park/unpark it. I dont leave the handbox in the obs due to possible humidity issues.

I have set slew limits on the +ve DEC axis before when 2 inch diagonal/camera is attached, but there's nothing set just now and it did it last night coming out of park - it's a real bugbear. I'm sure the scope thinks it's in the West coast timezone (even if it was made in China)!!!

Thanks for the suggestions.

Iain

[barkis]

Mel, If your problem Isn't solved by someone here, you could sign up to the Meade 4M forum.

Post the problem on their forum. There is a Guy there called Mark Sibole, who is a very knowledgable on LX scopes.

Ron.

[zero]

it's initializing the smartmount. It'll slew 2.5 hours (ish) in ra to obtain an encoder reference and the lx200 system uses a routine called Fingerprinting. The scope always knows exactly what part of the worm gear it is on. It's for Periodic error calculation and correction. Your original software would not have had this routine hence it seems different.

The easy (and my proffessional) answer is don't park it. The software used to park the scope is a bit poor in relation to the rest of the software. You are best off doing an easy alignment each time. This is good because unlike park it obtains a new gps fix before trying to calculate it's last position , park uses a small internal clock. It then finds where it thinks it should be and then uses gps to refine it.

The other option is that you simply turn the scope on, select a star in the menu, and manually push the scope there and sync it using the enter key. The next time you use the goto function it will obtain a gps fix and everything will function as it should.

If you do an easy align routine every time (as I do), this ensures no cord wrap issues -not that that's normally a problem - and guarantees spot on pointing every time. It just takes 2 minutes.

In polar mode you don't calibrate the sensor as polar alignment is a mechanical alignmenmt on the pole - the scope is physically pointing at it to start with . In alt-az, the scope needs to find north and two other points to work, hence calibrating refines it's idea of where north should be making the alignment more accurate.

I would not normally recommend attaching the camera to a diagonal as most diagonals are optically out by varying degrees. Only Everbrites are genrally spot on. You are best off directly attaching the camera to the scope, as no matter what diaginal you use, putting extra glass in the imaging train isn't ideal.

Mark Sibole

Steve

[barkis]

it's initializing the smartmount. It'll slew 2.5 hours (ish) in ra to obtain an encoder reference and the lx200 system uses a routine called Fingerprinting. The scope always knows exactly what part of the worm gear it is on. It's for Periodic error calculation and correction. Your original software would not have had this routine hence it seems different.

The easy (and my proffessional) answer is don't park it. The software used to park the scope is a bit poor in relation to the rest of the software. You are best off doing an easy alignment each time. This is good because unlike park it obtains a new gps fix before trying to calculate it's last position , park uses a small internal clock. It then finds where it thinks it should be and then uses gps to refine it.

The other option is that you simply turn the scope on, select a star in the menu, and manually push the scope there and sync it using the enter key. The next time you use the goto function it will obtain a gps fix and everything will function as it should.

If you do an easy align routine every time (as I do), this ensures no cord wrap issues -not that that's normally a problem - and guarantees spot on pointing every time. It just takes 2 minutes.

In polar mode you don't calibrate the sensor as polar alignment is a mechanical alignmenmt on the pole - the scope is physically pointing at it to start with . In alt-az, the scope needs to find north and two other points to work, hence calibrating refines it's idea of where north should be making the alignment more accurate.

I would not normally recommend attaching the camera to a diagonal as most diagonals are optically out by varying degrees. Only Everbrites are genrally spot on. You are best off directly attaching the camera to the scope, as no matter what diaginal you use, putting extra glass in the imaging train isn't ideal.

Mark Sibole

Steve

Hi Steve, Since I had no Idea you were an expert on the Meade LX scope, It was natural for me to direct Iain to the Meade site. As I have the LX90, I joined the group to glean information myself. Reading through the posts can sometimes to reveal an answer that you seek.

Scoring out Mark Siboles Name as you did, may be an indication I have upset you a little.

I sincerely hope not, because I may need to avail myself of your expertise at some point, now that I know you specialise on the LX's

Ron. :salute:

[zero]

No Ron, I forgot to add the smiley!! I hit post rather that preview DOH!

Marks a knowledgeable guy indeed. I'm no expert on Meade's really

Sorry to have given, you the peed off impression Ron, it takes a bit more than that to get me going

[bazza]

My understanding is the UTC offset should be on the 'factory settings' which if memory serves me right is about 13?

The reason for this is that the GPS will adjust if necessary when it takes a fix.

I think if you set the SMT (Smart Mount) to on - then park the scope - next time you turn it on, it shouldn't move.

This worked when I had my LX200GPS, but I bow down to Steve's knowledge, I'm sure he knows more than I about these scopes and mounts.

Barry.

[zero]

UTC offset is to compensate for the amuont of leap seconds aquired singe gps started. We are now on a 13 second offset and that is indeed in the factory defaults. There is no reason why smartmount should need to engage after parking.

One thing that springs to mind though, is don't wake the scope with the enter key That'll cause all sorts of things if I remember correctly. It' best to use one of the numberred buttons (may be wrong -haven't read manual in a while).

I Think Barry's right with the SMT though.

I just wouldn't park the thing.

[barkis]

No Ron, I forgot to add the smiley!! I hit post rather that preview DOH!

Marks a knowledgeable guy indeed. I'm no expert on Meade's really

Sorry to have given, you the peed off impression Ron, it takes a bit more than that to get me going

Thanks Steve, I feel better now, I just hope Iain,problem can be solved.

Ron.

[Mel]

Glad that's settled then.

Steve, as ever, you've provided an informative and detailed reply. I would like to use park, but hey - I'm already performing an alignment when it comes out squiffy, so it makes no odds. I'll just turn it off and move it to the park position.

I've heard two star alignment is a good path and I got a copy of a little program called BestPairs2 which suggests the best combination of 2 alignment stars depending on date/time/location and it seems to have come up trumps so far.

Cheers all - my scope is really only just coming into its own now that the alignment is spot on - pointing is excellent I'm getting targets in a medium power eyepiece across the sky now which gives me alot of faith in the instrument.

I'll set that UTC offset back and see if it helps but I'm going to take steve's advice and stop using park.

Iain

[RichieJarvis]

Hmm - i find this a little difficult to understand myself. Having just sold my 10" LX200R (the same as Iain's) I used to have it custom parked every night. The next time I came out, I would switch it on, it would do its smartmount thingy, and then when I asked it to goto, it was in the ballpark - except when I did something stupid like forgetting to disengage the guidescope before asking it to park!

The goto would fire up the GPS as the first operation, it would take a GPS reading, update its clocks, and slew.

I know that doesn't help you much Iain, as it doesn't solve your issue, but just letting you know that it worked for me, despite Steve Collingwood from BC&F saying that it doesn't!

Good luck mate - you'll get there - or get a decent mount

FYI - for those that don't know, I sold my LX200R for precisely this sort of thing - paying £1600 (LX200R plus wedge minus OTA costs) for a mount which doesn't perform, like I did with my LX200R leaves a bitter taste in ones mouth, especially when I now use an EQ6 Pro for half the price, and at least twice the performance!

Cheers,

Richie

[Mel]

I may have discovered the source of this problem. Re-reading the manual references to 'Smart Mount', I find it is very closely linked with parking the scope. Furthermore, there is no longer a 'Smart Mount' option anywhere on my Autostar II handbox! It should be in the Setup menu, but it's not there.

I remember when I tried to train the smart mount (the scope performs a sky survey of about 40 stars which you centre for it), but it never completed. I did about 3 runs, but none got through to the end, complaining (probably correctly :crybaby: ) about the accuracy of the polar alignment. The scope has probably got corrupt or incomplete SM data and is now refusing access to that menu item.

I will try and update the handbox - by reflashing it - and update with the results. Finger crossed for me everyone.

:nono:

[RichieJarvis]

Good luck mate!

Of course, you do know that as soon as its working to your satisfaction, the will roll in?

[Mel]

Cracked it!

Someone from the M4M forums pointed out that the scope should GPS fix before anything else happens. This wasn't at all what my scope was doing - it was waiting for me to select and goto an obj before doing a gps fix.

The GPS Alignment setting *must* be set to 'At Startup', not just *on*.

Many Thanks to all who contributed!

Iain

[philipok]

hi all,

been reading this with interest.. i had a related query.

I have a scopebuggy which I used to wheel out my lx200 and align on marks in the ground. I've parked the scope. I'm sure my position of the buggy will be a few centimetres out each time, so I wondered whether there was a quick way of "refreshing" the alignment without doing all the find home, level mount, north finding etc. i.e just use one star to refine the alignment.. any suggestions?

philip