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cantab

So I went and did exactly what everyone says not to do...

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Bought a scope off eBay. It was seemingly one heck of a bargain though, £25 for a Celestron Powerseeker 114eq, albeit with missing slow-motion controls. Last night the clouds consented to stay away for long enough to first light it.

The good:

  • Jupiter looked nice at 45x, the image seemed somehow crisper and more pleasing than through my refractor. Mind you that refractor's a hunk of junk so this isn't saying much.
  • The Moon looked OK. I didn't spend any great length of time studying it though.
  • The mount's obviously far from rock stable, but it moves smoothly and easily.

The bad:

  • The usual suspects. Useless SR4 eyepiece, couldn't even focus Jupiter with it. Rubbish finder.
  • The Orion Nebula was a total letdown. The trapezium was small but very clear, I hadn't seen it before, but the nebula itself? What nebula? This may well be down to conditions as much as the scope itself though, with Orion still low in the sky and a bright Moon.
  • Stupid equatorially stupid mounted stupid Newts! I spent more time looking for one of the tube ring nuts that I'd dropped when I was trying to rotate the tube than I did actually observing.
  • The mirror does look pretty filthy, though I know it's best left alone.

The ugly:

  • One of the plastic surrounds to the tripod leg screws cracked, so now I don't feel able to raise the tripod above its lowest height.

My plans now:

I've yet to even do a star test, still less collimate the scope, so I'll tackle that at some point soon.

I got a spare finder, the previous owner had had to replaced the bracket and ended up with a new finder too. I've filed out the aperture stop from it and will see if this makes it any better.

I've got an eyepiece from an old broken binocular. Holding this over the focuser showed it basically works and is a lower power than the 20mm Kellner I got with the scope, with the same apparent field, so now I just need to sort out a proper nosepiece for it.

If I'm happy with the scope optically, I might try making a Dob mount for it. I had an idea earlier on this front, which is to make a combined Dob base and transport case for the scope, so it will be relatively light and easy to get to a dark-sky site with.

Edited by cantab

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£25 sounds like a bargain. You should think about getting some decent quality eyepieces, they will make a difference!

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There was a youtube video about how to clean a mirror, can't remember which thread it was in now, it's probably quite easy to do with care.

I had a tripod leg screw plastic bracket crack on my EQ1 recently, I fixed it with a well-known brand epoxy resin and two metal tie-wrap thingies that the local Wilco Motosave sold me over the counter for about 78p each; jubilee clips would also work. Seems to have done the trick, probably stronger than it was originally. Those light-weight EQ tripods are very easy to break, you could probably just acquire a better tripod, or as you say an entire mount, but I think there comes a time when the scope itself won't be worth putting too much money towards.

Edited by jonathan

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I fixed my old eq-4 tripod screw plastic bracket with a bit of string - just tied it up as tightly as I could. Didn't have any problems holding a 150 refractor, certianliy no worse than it was before breaking it anyway. Very easy brackets to crack.

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Newtonians on equatorial mounts are a chiropractor's dream. The contortions you put yourself through to view can lead to criks in muscles you didn't know you had. This can be mitigated a bit if you set your scope up so that the EP is on top at the home position (difficult to view anything near Polaris though). Another cheap option are diy 'rotating rings' know as Wilcox rings. These are simple to make with long hose clamps and rubber tubing.

Here is a link to a page describing how they are made and used.

http://www.andysshotglass.com/wilcox_rotating_rings.html

As for the stability of the tripod you could either replace the legs themselves with diy wooden ones or make a 'eyepiece tray' to link the 3 legs together lower down.

Pat

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If the finder has an aperture stop inside it. Just bin it, it's not wrth filing it. You will get CA something awful but at least you'll be able to see some fainter objects than just the moon and planets through it with it gone.

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This can be mitigated a bit if you set your scope up so that the EP is on top at the home position (difficult to view anything near Polaris though).

Pat

Or use a 45 or 90 degree diagonal. Rotate that and your problems are solved.

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Or use a 45 or 90 degree diagonal. Rotate that and your problems are solved.

I'm not sure my newt has enough focus range to accommodate that. I'll have to try it and see, might be a solution for many newts on eq mounts.

Thanks for the suggestion.

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Had a couple more nights of frustration with the bleeding thing, but tonight was a better story. I'd tried to collimate it a few days ago (following Astrobaby's guide), the secondary adjustment was hopelessly erratic so I took the secondary holder out, slipped in a milk bottle washer under the adjustment screws and that made a world of difference, the secondary now behaved predictably when I tweaked the screws. I still need to get a Cheshire to sort the primary out though.

The finder needed tape round it to properly fit the holder. Again, tiny little change ends up making a world of difference, it can actually be aligned now.

I did a search for suitable nosepieces for the binocular eyepiece, and found a cardboard tube that fit well for the purpose.

Wasn't out for long tonight before the clouds rolled in, but I took another look at the Orion Nebula. In the "new" low power eyepiece, which I guess is a 30mm Kellner or thereabouts, I could see the two "wings" extending away from the Trapezium with averted vision.

I tried to star test it, it looks nothing like the textbook images and I'm not sure what to make of it.

I had a look at M35 in Gemini. Locating this was a job for the finder, which got me to Eta Gem, and then with the ~30mm EP I scanned north a little and picked up the cluster, a nice group of faint stars that stood out clearly. I think such open clusters are going to be objects where the scope can really deliver more than my binoculars, which tend to show them as faint fuzzies with two or three visible stars in them. The finder's still naff, but at least it shows stars I can't see with the naked eye, which I kind of need in skyglow city Birmingham.

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