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Meade LX3 polar alignment help please

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#1 shawnhar

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Posted 27 January 2011 - 11:21 AM

Reposting here in hopes of a response, originally in beginner forum but no response.
I recently got a mid 80's Meade SCT (LX3 2120) on a wedge with forks and I am trying to learn polar alignment. From what I can gather, this is how to start....

Point tripod/wedge North using built-in compass
Level Tripod
Set wedge to 36* - My Lat
Level fork arms and lock RA
Point OTA straight up in Dec and level top of OTA
Set Dec circles to 36*
Now when Dec is 90* should be on Polaris
Adjust AZ (left/right) with fine tune screws to center Polaris. (I know, probably have to adjust Dec as well)

Now...I know Polaris is not Celestial North, pretty sure I can use Stellarium to show it, and I have some of those kooky circular star charts that have the celestial pole in the center, point is I can figure out which direction it's supposed to be from Polaris and it's like 43 arcmin. (I think)
Now...I have this finder scope...10x50 Illuminated Polar Finder Scope. It has crosshairs and an outer circle. (2 lines make up the outer circle)
Can I assume somewhere in this outer circle is where Polaris should end up after pointing the scope true North?
If that is the case then it seems like if I were lined up right and spun the scope in RA, Polaris would track inside the illuminated outer circle of the polar finder scope....am I right? I haven't measured the arc of the circle or anything, but I can't find the original polaris reference thingy you are supposed to use with this finder scope.
And is there anything wrong with the above steps?

#2 GrampianStars

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Posted 27 January 2011 - 03:49 PM

after level fork arms and lock RA
Point OTA perpendicular with fork arms.
(i.e. tube inline with forks.finder on top.)
set circles to "O"
Polaris should be in field of view somewhere (26mm)
" Now rotate the tube until the RA setting circle reads 2 hours 31 minutes and the Dec circle reads +89 degrees 15 minutes."
These are the coordinates of Polaris and the Pole Star should now be in the finder’s crosshairs.

If it’s off, once again move the mount in latitude (altitude) and azimuth to center Polaris.

should take 10 minutes tops :grin:

#3 Brian Risley

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Posted 27 January 2011 - 08:18 PM

To use the RA Circle you first need to get the RA circle set. Get close by lining up 90 on polaris, then you can go to a known star, set the RA circle to the indicator under the RA Lock, then move it to the 2:31 position and 89 15.
There are instructions for the polar finderscope and you can download the needed calculator if you don't have them. Check the LX-5/LX-6 Yahoo group for download of the calculator and check the manuals for instructions on it.
I just got one with my LX-6 recently and still don't have it all figured out yet myself.
If you are going to use a permanent pier, do the drift alignment to get it closer.
Brian

#4 shawnhar

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Posted 28 January 2011 - 08:11 AM

Awesome thanks for the tips!






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