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  #1  
Old 03-11-2017, 06:32 PM
Wurgle (Neil)
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Meade LX200 GPS 14"

Hi Everyone,
I'm new to this forum and also new to stargazing.
I have a few questions that I'm hoping the assembled minds can help me with, but I understand that they are clearly extremely basic, so go easy....

My father died a little while back, and he was a keen astronomer.
Unfortunately this wasn't a hobby that I could really join him in given distance and various other factors, but I have now inherited his equipment, hence the title.

I have my own young family and thought it would be great to try to share the hobby with them, so I have been trying to set it up to use recently.

Apart from its huge size which means it's effectively not really portable I have been completely unable to get it working, even in the simplest of ways!

I set up the tripod, put the telescope fork mount on that (he had a wedge is it? but I haven't been able to fit that), assembled the most basic optics I could work out (eyepiece, prism / mirror and a couple of short tubes) onto the back of the telescope, but no image?!

I have read and re-read the manual, focused between both end stops, but nothing other than a white haze when I look at the moon.
It's almost like all I can see is "inside" the eyepiece if that makes sense?

When I remove the eyepiece I can see a perfectly formed and focused moon on the mirror in the prism though?

I'm sure I must have missed out some vital part or other that is stopping this from working?

I feel very fortunate to have this telescope, but I am frustrated that I seem to have failed at the very first hurdle trying to view the simplest of objects!!

All help gratefully received
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  #2  
Old 03-11-2017, 07:17 PM
Wavytone
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Ha, understand your plight ! I seen you are in the UK ... if all else fails I suggest you find an astro club near you and make friends with a seasoned observer who knows how to set this up.

What you have is a very serious kit - well beyond beginner level so you face a steep learning curve. However I’m quite sure the locals will be keen to help in return for a look through it.

Unfortunately I’m in Sydney, which is a wee bit too far away.

Ok... from the ground up:

1. Tripod goes on the ground. When setting up it helps significantly if the tripod is levelled so the top is accurately flat, use a clinometer or smartphone app and adjust the legs accordingly. It’s like wrestling with a bagpipe spider.

2. Wedge bolts onto tripod. The purpose of the wedge is to tilt the scope so the fork tines point at the north celestial pole (Polaris is close enough) and it has adjustments accordingly up/down (altitude), and left/right (azimuth).

3. Telescope bolts onto wedge, with the tines of the fork pointing at the north celestial pole. The pole is at an elevation above the horizon equal to your latitude.

For a first approximation use a star map to locate Polaris, and use a clinometer to adjust the wedge so the fork tines are inclined above the horizon at an angle equal to your latitude. I leave it to you to figure how this is done in detail.

4. Eyepieces are usually marked by focal length eg 40mm, 25, 12 or 9. Start with the one that has the longest focal length - probably 25, 30 or 40mm. This will give the lowest magnification, to make this easy.

Once you have an eyepiece in the back focussing is by means of the knob on the back of the telescope. That you didn’t find focus is not a surprise, most noobs miss it completely at first try. Turn the knob more slowly and pay attention to what you see as you do. It will focus, guaranteed.

Eyepieces with shorter focal lengths mean more magnification. Focussing becomes more critical and so does tracking the object. Use these only on the moon or bright planets (Jupiter, Saturn, Mars etc).


5. Plug into power and it should track, ie make the stars stand still despite the rotation of the earth.

6. Strongly suggest you buy a copy of Norton’s Star Atlas, or one of the books by Patrick Moore - in addition to the maps these provide a wealth of how-to stuff for beginners. Then Sky Atlas 2000, or the app Sky Safari Pro.

Last edited by Wavytone; 03-11-2017 at 09:05 PM.
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  #3  
Old 03-11-2017, 08:47 PM
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ChrisM
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Neil,
With the Meade 14", something else to check is that the mirror lock knob is turned to the 'unlocked' position. If it's in the 'locked' position, focusing is not possible via the normal means, unless the mechanism is broken (by say, forcing it.)

I assume that the original focusing mechanism hasn't been replaced with a Crayford-style focuser? If it has been replaced, it's possible that true focus is out of range. If this is the case, then set the Crayford-style focuser at about mid-range, then unlock the mirror and use the original focuser to bring the scope to focus (as viewed through the eye piece), then lock the mirror and use the Crayford-style focuser for subsequent focusing.

Once again, some help from a local astronomer would be highly recommended.

Good luck!
Chris
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  #4  
Old 03-11-2017, 09:51 PM
Wurgle (Neil)
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Thanks Wavytone and ChrisM
Having read quite a lot of material (including the instruction manual found on line) I am fairly confident that I have mounted the telescope properly, albeit not on the wedge, and that there are no additional items affixed to the scope that I wouldn't expect e.g. different focus mechanism.

I have unlocked the mirror using the rear knob and can see the image moving in and out of focus when viewed directly on the prism without the eyepiece when I adjust the rear focus knob.

When I then fit the eyepiece however, all I can see is a completely white / hazy view that does not resemble anything, even something wildly out of focus, even at fairly low magnification e.g. 25mm.

It seems to me that either I have not fitted something e.g. some kind of extension tube to allow the eyepiece to resolve on the focal plane, or there is something more fundamental wrong that I am missing?

Thanks again for your help
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  #5  
Old 04-11-2017, 12:47 AM
raymo
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You can check if for some unfathomable reason it requires an extension tube
by loosening the eyepiece retaining screw[s], and whilst looking through the eyepiece slowly slide the eyepiece out of the holder and see if it comes to focus when several centimetres from the focuser.
raymo
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  #6  
Old 04-11-2017, 01:29 AM
Wurgle (Neil)
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Thanks Raymo,
I did try that but it didn't seem to make any difference

I've tried several eyepieces as well.

I just don;t understand why it would create an in focus image in the mirror of the prism, but then not be visible through the eye piece.

I'll keep trying
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  #7  
Old 04-11-2017, 02:04 AM
raymo
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Maybe the opposite of what I was suggesting is happening. Take the diagonal out and try the eyepiece directly into the back of the scope, again moving it away from the scope if necessary. The focusing knob does many turns from one focal extreme to the other. I presume that you are sure that the
focuser is moving through its full range of movement.
raymo
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  #8  
Old 04-11-2017, 02:46 AM
Wurgle (Neil)
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I did think that perhaps after a period of not being used and then transported that the mirror might be stuck, but it seems to move.
I say that because when I look through with only the prism in place I can get the image to go in and out of focus (changing size significantly at the same time) which is what I think I should expect?
The focuser seems to act along it full length of travel (or at least through its full number of turns)
I will try your idea, and then see if I can project an image onto some paper or something.
Right now all I get is what looks like a view of the inside of the eyepiece (rather like floaters in your eye if that makes sense) roughly illuminated by the source
Thanks
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  #9  
Old 04-11-2017, 06:05 AM
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JimsShed (Jim)
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Hi Neil. Maybe post a pic or 2 of the back of the scope with the eyepiece in so the guys can see the setup. I would’ve expected that you simply need to put in the diagonal then eyepiece into that. No extension tubes. The whiteout indicates it’s not focussed.
I’m tending to think that there’s an extension tube or focal reducer between the scope and the visual back which needs to be removed. You did mention a wedge so maybe it’s last use was in a photography configuration.
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  #10  
Old 05-11-2017, 06:45 PM
Wurgle (Neil)
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Here are a couple of pictures as requested (so sorry for the image sizes, I couldn't find a way to reduce them?)

http://photouploads.com/images/a7fb0c.jpg
http://photouploads.com/images/c2b938.jpg

So the images show the assembly attached to the back of the scope and an "exploded" view of the components.
When I look through the prism with no eyepiece during the day, I can see the image of my garden very clearly.
When I look through the eyepiece alone, with about 150mm of eye relief I can see clearly.
When I combine the two with about 150mm of eye relief I can see clearly, I just cannot get an image to form when my eye is at a more reasonable distance when focusing via the scope, which may indicate that the focus mechanism on the scope is broken, but it doesn;t seem to be?
I'm sure this will lead someone to an "AH HA" moment and tell me how daft I'm being and that all I need to do is.....
Over to you
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  #11  
Old 05-11-2017, 07:58 PM
raymo
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Have you yet swivelled the scope away from between the forks, and
inserted the eyepiece directly into the back of the scope, and as you slowly pull the eyepiece out of the scope see whether the image[if there is one] is
improving or worsening focus wise?
It just occurred to me that what you are trying to view might be too close to the scope; the minimum focusing distance can be many metres. Have you
tried looking at something further away than your back yard?
raymo
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  #12  
Old 07-11-2017, 09:44 AM
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Have you removed the plastic caps off the eyepiece ? I have seen that done more than once .:question.
Brian:
Quote:
Originally Posted by Wurgle View Post
Thanks Wavytone and ChrisM
Having read quite a lot of material (including the instruction manual found on line) I am fairly confident that I have mounted the telescope properly, albeit not on the wedge, and that there are no additional items affixed to the scope that I wouldn't expect e.g. different focus mechanism.

I have unlocked the mirror using the rear knob and can see the image moving in and out of focus when viewed directly on the prism without the eyepiece when I adjust the rear focus knob.

When I then fit the eyepiece however, all I can see is a completely white / hazy view that does not resemble anything, even something wildly out of focus, even at fairly low magnification e.g. 25mm.

It seems to me that either I have not fitted something e.g. some kind of extension tube to allow the eyepiece to resolve on the focal plane, or there is something more fundamental wrong that I am missing?

Thanks again for your help
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  #13  
Old 08-11-2017, 01:50 AM
Wurgle (Neil)
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Thanks
I think I can safely say that I remembered to remove the eye caps
Unfortunately I can’t try anything else for a few days as I am in South Africa, but will still gladly receive further suggestions in the meantime.
Maybe it’s not as obvious as I thought it would be?
Can anyone comment on the eyepiece / prism arrangement I have in the photos and if it “looks right”?
Cheers
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  #14  
Old 08-11-2017, 06:09 PM
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Neil , I dont see anything wrong with your set up , it's almost identical to what I have on my C9.25 and I don't have any problems and focus is found easily in all my eyepieces , mainly TV's Plossl's , Radians , Panoptics and Naglers all reach focus .

I would put my money on the mirror lock not fully releasing fully .

Can you see the primary moving when the focuser is turned both from the front of the OTA and looking it the diagonal without an eyepiece as you should see it moving back and forth .

Here is mine , as I said almost the same as yours .

Good luck .

Brian.
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  #15  
Old 08-11-2017, 07:07 PM
Wurgle (Neil)
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Thanks Brian,
I agree that focus must the problem, or at least part of it.
Both the mirror lock and the focus mechanism seem to move freely / as I would expect, and don't seem to be disconnected or damaged.
I haven't checked from the front of the OTA, but when I look down the diagonal without the eyepiece, I can see the image clearly, I can see it moving in and out of focus and getting smaller and larger as it does so.
As to whether the primary mirror is actually moving sufficiently to achieve this I am not sure and further investigations will have to wait until I get home.
Thanks again for the thoughts
Neil
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  #16  
Old 08-11-2017, 11:19 PM
raymo
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As I said earlier, are you focusing on something sufficiently far away?
Minimum focusing distance can be many metres. I have a pair of zoom
binoculars with minimum almost 20 metres.
raymo
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  #17  
Old 09-11-2017, 12:56 PM
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Good point I would think that 500 metres would be minimum for a 14 inch SCT .
Brian.
Quote:
Originally Posted by raymo View Post
As I said earlier, are you focusing on something sufficiently far away?
Minimum focusing distance can be many metres. I have a pair of zoom
binoculars with minimum almost 20 metres.
raymo
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  #18  
Old 17-11-2017, 06:15 AM
Wurgle (Neil)
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Ok,
SO thanks to everyone who has responded.
It is fixed!

It seems that although it was focusing, it was not doing so along its complete length of possible travel.

My father had not used the instrument for several years and it had lain without TLC for that time, and I think that the lubrication on the thread attached to the primary mirror had dried up / seized.

I followed some internet instructions and partially dismantled the focusing mecahnism and discovered that although the primary mirror was moving, the whole mechanism was stopping half way along the threaded rod.

A bit of fettling and greasing later, and I now have a working scope that seems to produce some nice images (although the seeing has been very poor recently in the UK).

Hopefully now I can contribute a bit more usefully to the forum, now that I can actually see stuff
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  #19  
Old 17-11-2017, 05:59 PM
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Awesome news , now get out and enjoy your beautiful telescope and please keep us informed as to the viewing sessions you well enjoy .


Oh yes , photos .

Brian.
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