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  1. #1
    hallcp's Avatar
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    Default Question about Polar Viewfinder usage



    I bought the polar viewfinder from a Meade LXD75 telescope mount off ebay. As I expected, it has an illuminated reticle, etched with the little dipper and Polaris. I figure that if I can mount this on my wife's old fork-mount Celestron it should be easier to get a good polar alignment.

    But the mounting isn't quite what I imagined and the downloadable LXD75 manual is no help. It seems to me that the polar viewfinder must be free to rotate in it's holder, but there's no such mechanism with the one I have. It has a mounting ring with threads on the outside and setscrews on the inside.

    Can someone describe it's correct usage to me? You do have to be able to rotate it, right?

    And if this works like I think it should, why aren't such gadgets more readily available? This should make accurate Polar alignment possible without a lot of trial and error if I understand it right, but I couldn't find one to buy new.

    Thanks!
    Charles Hall

  2. #2
    RussL's Avatar
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    Charles, I tried to get a look at one, but just couldn't find it. Like you, I would assume it has to rotate. I'm also imagining that the threaded part is designed to thread into the LXD mount. ??? Surely you'll need to make something, I'd think, to afix it to a fork mount.

    Wish I could help. Just wanted to give ya a reply. Maybe someone else will know more and come along. Good luck, pal.

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    Have one never use it

    Compass and digital protractor are all I use

    if you set these right then Polaris should appear in EP

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    Quote Originally Posted by trevorw View Post
    Have one never use it

    Compass and digital protractor are all I use

    if you set these right then Polaris should appear in EP
    I'm still in the Stone Age here Trev, I use a compass and plastic protractor and plumb line

  5. #5
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    ... well ... there is one in my CG5 ... never pulled off the caps to look through it though ... I also have one that showed up with a box of stuff I bought off eBay ... hmmm ...

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    Guys there is a point here.

    Charles has a fork mount alt az SCT and the Polar scope is intended to fit a GEM.

    Its something I wouldn't even contemplate but I guess anything is do-able?

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    Charles, you still here? I was just thinking that maybe you could mount it on the side of one of the forks. You'd need some kind of rings, I guess, even if they're plywood and a base. You might could stick it on there with some double-sided tape. The trick would be to make it alignable.

    I dunno, man. Sounds like a tricky project.

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    Quote Originally Posted by RussL View Post
    Charles, you still here? I was just thinking that maybe you could mount it on the side of one of the forks. You'd need some kind of rings, I guess, even if they're plywood and a base. You might could stick it on there with some double-sided tape. The trick would be to make it alignable.

    I dunno, man. Sounds like a tricky project.
    ... see ... that's what I was thinking ... make it into a small scope in itself ... thought you would have to collimate (or maybe align is a better work in this situation) and then align it like a finder scope ... then align the mount ... cold become a cottage industry here ... lol ... seriously though ... you could easily use a piece of tubing/pvc, some 50mm mounting rings, a plumbing fitting that you could screw the polar scope into ... hmm ... I can see that I will be playing at work again ...

    ... of course ... then comes the whole issue of aligning it on the forks, or rather, the wedge, or some part of the mount that actually points north ... yeesh ... yeah, this could be a project ...

    ... yepper ... sounds like shooting some start trails might be in order ... lol ...
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  9. #9
    hallcp's Avatar
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    Default

    Well, my original plan was to simply replace the existing finderscope on the SCT and have a mount loose enough to rotate to offset from Kochab (or Alkaid). I was able to make such mount, but it does not hold alignment when I turn it round. So I could do like the "Kochab's Clock" guy, and align it to a certain angle, then wait until the time of night when that angle matches Kochab. I believe this would work, but in reality I suppose this illuminated reticle is no more helpful than any other illuminated reticle for this purpose!

  10. #10
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    Well then, what about not turning it on, but just look through it to see Polaris. If it's centered, you'd be good for visual observing. Can you still see the other things in the reticle with it turned off?

    Then, you could just tighten it down enough to stay aligned. No?

 

 
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