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James Cunningham
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Reged: 08/07/10

Loc: Maryland
Slews too high??
      #5780907 - 04/05/13 11:43 PM

My slews with my 11 inch SCT are consistently too high. The object that I am slewing to is within the FOV but always up near the top of the eyepiece. What would cause this? Thanks.
Jim


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CharlesW
Pooh-Bah


Reged: 11/02/12

Loc: Chula Vista & Indio, CA
Re: Slews too high?? new [Re: James Cunningham]
      #5780950 - 04/06/13 12:17 AM

If you are using a wedge, are you resyncing after your polar alignment?

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James Cunningham
Post Laureate
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Reged: 08/07/10

Loc: Maryland
Re: Slews too high?? new [Re: CharlesW]
      #5781467 - 04/06/13 10:36 AM

I am on an alt/az mount.

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rookie
Good Night Nurse
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Reged: 01/14/06

Loc: St. Petersburg, FL
Re: Slews too high?? new [Re: James Cunningham]
      #5782358 - 04/06/13 06:26 PM

What focal length eyepiece are you using when this occurs? If you are using high power and your field of view is small, that level of accuracy is acceptable.

Do an alignment with a narrow field eyepiece like a plossl for better centering or use an eyepiece with cross-hairs for your alignments. You can also fine tune your alignment by adding a "sync" alignment with your target. The steps are covered in the manual.


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rmollise
Postmaster
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Reged: 07/06/07

Re: Slews too high?? new [Re: rookie]
      #5786247 - 04/08/13 03:41 PM

I think you received some pretty good answers on the Yahoogroup...but if you want more...

As long as the object is in the field of a medium power eyepiece, this shouldn't be a problem. But some things that can cause it, you axe?

--Alignment star choices.
--Scope balance.
--Centering of alignment stars (use the up and right keys only for final centering, use a medium power reticle eyepiece).

My own NS11 won't center every single object from one side of the sky to the other, but it will place anything in the field of a 12mm Nagler, or in the field of my Mallincam Xtreme, even at f/5 - 6.


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James Cunningham
Post Laureate
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Reged: 08/07/10

Loc: Maryland
Re: Slews too high?? new [Re: rmollise]
      #5786279 - 04/08/13 03:58 PM

I got much better at getting an object fairly close to center by shifting the counterweights. So, I think the scope was out of balance.

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