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darryl
04-18-2010, 12:42 AM
As a reward for connecting a renter with a rentee, I've been given a Meade DB-2102 telescope. Looks like a 4 inch, with an alt-az drive system which by the way is telling me to consult the instruction manual. I'm not sure what else is supposed to come with the telescope, but so far I haven't got any eyepieces, just a right angle 'look into' coupling. In the tripod stand, there's a tray with three 'nests'- I'm assuming homes for eyepieces. On the side of the main body there's a flimsy holder of some kind- what is supposed to be a finder scope. I don't know what that is supposed to consist of, and whether or not parts are missing from that.

Just wondering if this is a reasonable telescope and if anybody has any experience with it.

dp
04-18-2010, 01:00 AM
It's a bit of a clunker. Not one of Meade's high points. but the price was right. Eyepiece optics can be found at common telescope components sites. If one were in the market, a Celestron C-90 or better would be more fun and the prices are coming down. Very compact, and can be used for lenses on cameras.

darryl
04-18-2010, 01:21 AM
Actually it's a DS-2102. Now that I've got it in the light I can read the nameplate properly. DP, you have probably figured this out- it does seem kind of flimsy, and is of course like most things these days made in China.

dp
04-18-2010, 01:31 AM
Used to be the heaviest parts of a telescope were made of glass and metal. Now it is plastic. Many of the low-end scope digital drives were pulsed rather than continuous drive, so images will smear. Color correction is likely non-existent in that model, so aberration will add to smearing to produce quite a colorful photo.

I have an 8" Meade Dobsonian reflector scope and love it. No drive, of course, but it's a lot of fun for direct eyeballing the sky. It's close to 30 years old and the mirrors need resurfacing in a big way. That's my pocketbook saying time to retire it and get a good driven scope next time. I think a computer drive from the comfort of the living room like Evan's rig :)

darryl
04-18-2010, 02:23 AM
Well, I've been playing with it for several minutes now, having downloaded the user manual. Dennis, you've been very kind in calling it 'a bit of a clunker'- mechanically at least it's a wet noodle- as Neil Young once said 'a piece of crap'.

I'll probably take the mount apart to see if there's anything I can do to stiffen it up. If the electronics works as the manual describes, I'll at least learn something about astronomy, the stars and constellations, etc.

Optically it seems like it might be ok, at least from what I can tell without the eyepieces. The red dot finder gave me a laugh, so I guess it is worth something- :) The focus mechanism- well, let me just say I hope this jittttering in my right eye goes away by morning :)

I've learned one thing already- for me to be happy with a telescope/drive system, it would have to be at least an order of magnitude better than this one.

But even having discovered all this, I'll probably be able to have some fun with it.

tyrone shewlaces
04-18-2010, 02:59 AM
Those red dot finders aren't too bad and some guys like them.
You could always consider it the seed for "nail soup" and make an equatorial or computer drive for it from scratch, then upgrade the optics to a nicer scope once the drive is up & running. It would be a fun machining project, and a nice item for machinist's show & tell.

darryl
04-18-2010, 10:51 PM
Well, now I see that it wasn't meant to be so sloppy- I've taken the alt drive apart and it's broken. I can possibly see a way to fix it, but some re-design of the clutch will be needed. This is an obvious weak spot, but I think I can improve it. Now I need to have the az drive unit apart and see what if anything is so 'spongy' in there.

The alt drive has a forked drive dog nut that tightens against the worm wheel to engage the motor drive. The actual mount for the telescope tube is driven by the dogs on that nut. Because the forked nut has to slide through the telescope tube mount, there will always have to be some play there. I don't see the point of eliminating play in the motor drive system, right up to the worm wheel, only to end up with a built-in slop that you can't adjust out right at the end of it all. Poor design I'd say.

No eyepieces yet, but I've been told they are in a box somewhere. Chances are I will have them in hand in the next few days. As far as the tripod I'll be digging out my old one and that will be a steady base. A flat plate is all I need to mate the telescope to the stand, so that's an easy upgrade.

Once I get back from having coffee, I'll look into the base unit, the az drive.

I should be able to learn quite a bit from the manual, and I should also be able to run the drives without needing the telescope attached. The first 'alignment' I get will of course not be correct, but it will prove the ability of the system to go to positions indicated by the parameters in memory. That will be a test of the electronics, and also of my ability to make sense of the manual-

Oh, and as a last point of interest at this time, a friend has a video unit that will attach to this scope. I should be able to see on my computer what the telescope is looking at. That will be interesting.

tyrone shewlaces
04-18-2010, 11:47 PM
So are you referring to using a camera tripod to mount it to? That will hold it to give the scope a look-see, but compared to even a flimsy telescope tripod, the average camera tripod will probably be wiggly beyond your wildest dreams. The video unit may be a real help since you won't actually have to touch the scope at all to view through it. That camera tripod will probably shake for 30 seconds after the slightest touch or wind. But you'll learn some things along the way and there will probably be moments of glory here & there anyway. I always liked playing with telescopes. You can see so much more than naked eye even with the cheapest, worst scope. Nice ones are just wonderful.

I always wanted to fiddle with a CCD and some software. Never had the money to try it out yet. Picking the software is some fun in itself.

As for yer basic astro-software, there is a bunch to choose from. For whatever reason, I really like Hallo Northern Sky. There are slicker packages out there to be sure, but you might check it out anyway. What the heck - it's free! I'm not sure since I never had the chance to try it, but I think it may interface with video stuff for basic viewing at least. I'll defer that advice to those with actual experience.

http://www.hnsky.org/software.htm

darryl
04-19-2010, 12:12 AM
Tyrone, the tripod I have in mind is built like the proverbial brick ----house. It's not something that you would consider portable, but you can fold it up and take it with. It is all metal, steel legs, heavy and solid. There is no camera tripod I've ever seen that comes even close to being as rigid. In fact, it has a telescope on it right now, just not a very good one. It's a 2 inch, looks like it might be a tasco or a copy of one-

At this point, I've had the base unit apart, the az drive, and there's nothing broken or amiss- it's got too much flex in the assembly that carries the worm gear for the final drive. Not much I can see to improve that, and I'm not going to try for now anyway. There's a somewhat flimsy steel post that takes some of the force from the worm gear shaft, and I'm guessing it's on the side that resists the forces from the worm gear moving the telescope in the same direction that the stars appear to move across the night sky. Should be ok.

Next step- put my laundry in the washing machine, then try to make sense of the manual.

The Artful Bodger
04-19-2010, 04:02 AM
Darryl, the worm drive should not have much force on it as the entire ensemble of telescope and Alt-Az drive should be near to a point of balance.

huntinguy
04-19-2010, 09:36 AM
I give you fair warning!!!

My wife was thinking about getting a telescope... So a friend where I work gave her a small one... Then she wanted one that would slew... then she wanted a bigger one that would slew... Then she started teaching and needed a bigger one... then she needed one for the students to look through... I now have one room that is full of scopes.

In all honesty, the study of astronomy is a very useful waste of time: time of year, direction, time of night even your location can be found by watching the stars... It is amazing what can be learned by the study. A few years ago we went to a star party on Table Mountain just outside of Ellensburg Washington. Man.... What you can see and learn.

Eye pieces can be had from around $100.00 on up to the price of a car - Google around for them. The 8" scopes my wife bought were from a small company... Don't recall the name at the moment... but they were the same quality and several hundred less than Celestron.