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gumbatman
member
Reged: 06/12/09
Posts: 22
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Hi,
I'm still a very green newbie because it has been cloudy and/or raining almost every night for about a month (which is about when I got my ETX-80)!
For the few nights I have been able to try, I followed all the directions to get the telescope to auto-align. Each time I try, it seems to be a good foot ( I don't know how many degrees) or so off to the left of the stars. Even after I found the stars and set the telescope, I had it look for the moon. Then again, it was off to the left for about a foot or so. I did go through training the drive, but that didn't seem to help.
I thought it could be a problem with how I set the time and daylight savings, but I checked that several times (which doesn't mean I am doing it correctly).
I am sure I am missing something obvious here and doing something really stupid, but I can't figure it out.
Any suggestions would be greatly appreciated.
Thank you.
-Rob
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caheaton
super member
Reged: 05/26/09
Posts: 155
Loc: SW Ohio
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When I first got mine, it was consistently off that way. It did turn out to be the time. Make sure you set your controller to DST first, then set the correct time. Also make sure your tripod is level (I do this by placing the level on the base above the azmith lock). After the tripod is level, level the scope with it pointed north (use Polaris if you can rather then the compass). Having done that, go through your alignment. It is normal for the first two stars to be off a bit, but after completing the alignment, all of my goto's have been dead on...even with the 9.7EP left in place (and still in the FOV if I use the 6.4EP).
Also, make sure your batteries are fresh as this can also have a dramatic affect on goto accuracy.
One last thing, if you can, set your time and location using a GPS for the best accuracy.
Craig
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Craig
Ancient Tasco 4.5" (from back when Tasco's were good)
Meade ETX-80
Orion XT10i
Meade Super Plossls 6.4, 9.7, 15 & 26mm
Zhumell Z Planetary 3mm
Agena Ultra Wide 30mm
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Treehopper
professor emeritus
Reged: 07/29/08
Posts: 582
Loc: Upstate NY
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Hard to tell for certain, but it sure sounds like you're off about an hour, which immediately tells me your DST might be set incorrectly. If you have to, double-check your DST setting, turn it off, check your time, then go and turn it back on and re-check your time. There are times when certain devices will actually change the entered time rather than modify it internally. I think I even went 'round with this on the 125 before I figured it out.
Make sure you follow Meade's alignment instructions to the letter. I'm not sure on the 80, but on the ETX-125, you had to turn the scope a certain distance from the "home" position to orient it and keep it from coming up against the hard stops built into the gear train. It can seem a little confusing and over-plumbed at first, but once you successfully set it up a few times, you'll be an old pro and be able to set the whole thing up and start observing in <5 minutes.
Just take your time (no pun intended) and let us know how you make out! 
--------------------
Tim
Champion of small aperture scopes everywhere!
Meade ETX-125PE
Meade ETX-80
Celestron FirstScope 76mm Mini-dob
 Updated: 09/16/2009
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gumbatman
member
Reged: 06/12/09
Posts: 22
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Craig,
There is about a foot or so distance between pointing the telescope to magnetic north, then there is pointing it to Polaris. Polaris is about a foot over to the right (aha!).
I remember learning something in Science class about the difference between magnetic north and Polaris - or was that just a faded memory from a long time ago?
So, Polaris is more accurate than magnetic north? Does it make a difference where I live (30 miles north of New York City)?
Thank you!
-Rob
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caheaton
super member
Reged: 05/26/09
Posts: 155
Loc: SW Ohio
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That is likely the source of your error. Polaris is much more accurate for North then magnetic north.
Craig
(I just looked it up, magnetic North is 15 degrees west of true North for New York City...quite an error to introduce if you were relying on the compass...plus I've noticed that the compass doesn't point true north when it sits in the eyepiece holder...it tends to get pulled a bit (I think it's west, but don't recall) by (I suspect) the magnets in the scope's motors).
Edited by caheaton (07/08/09 01:07 PM)
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astrowolf67
member
Reged: 12/15/07
Posts: 94
Loc: Western Kentucky
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Yes, always use Polaris as your north setting, instead of magnetic north. And, as recommended, set to DST, then check the time. I also enter my location by zip code rather than choosing the nearest city.
Tim, as you will find out when your ETX80 arrives, there's no hard stops to mess with. It's simply level the tripod, level the scope, point it north, and start alignment. Using an external power supply, cords can become wrapped up easily, but, there is a cord wrap setting, which supposedly prevents the smaller ETX's from doing 360's all night. It helps a lot to turn it on, but, I still occasionally get cord wrap.
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David
"Seek the Spirit of the Wolf, for He holds the Secret of Life."
Edmund Astroscan/Meade DS 2000 tripod
Meade ETX 60
Tasco 60mm EQ
Meade 114 NT/LXD75
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Treehopper
professor emeritus
Reged: 07/29/08
Posts: 582
Loc: Upstate NY
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Quote:
That is likely the source of your error. Polaris is much more accurate for North then magnetic north.
Craig
(I just looked it up, magnetic North is 15 degrees west of true North for New York City...quite an error to introduce if you were relying on the compass...plus I've noticed that the compass doesn't point true north when it sits in the eyepiece holder...it tends to get pulled a bit (I think it's west, but don't recall) by (I suspect) the magnets in the scope's motors).
Care to guess how much 15 degrees is in terms of the Earth's rotation?
360 degrees / 24 hours = 15 degrees per hour (give or take, true sidereal time makes me woozy!  )
Sooo, either way you slice it...the difference between magnetic and true north, or a wonky DST setting, you're going to be about 1 hour (15 degrees) off.
Another satisfied customer! 
--------------------
Tim
Champion of small aperture scopes everywhere!
Meade ETX-125PE
Meade ETX-80
Celestron FirstScope 76mm Mini-dob
Updated: 09/16/2009
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