Last updated: 6 October 2005
Subject: Meade DS-114-AT-A Sent: Wednesday, October 5, 2005 00:27:51 From: DHoelzer@cyber-defense.org Thanks for the great site! I'm sending this note to add a bit to the coverage of the DS series, which seems a bit light, and to disagree with some of the negative comments regarding the DS-114 models. I've recently purchased a DS-114-AT-A at Sam's club. The last time I did any kind of astronomical observations was back when I was in University, but when I saw this 114mm reflector with GoTo for $200, I just couldn't walk past it. I've read a number of comments regarding these scopes, most of which are negative. Here's my story: I brought the scope home and opened everything up. This scope is, in many ways, excellent for a beginner. The whole thing (except for the motors and the finder scope) comes preassembled. Also, I was surprised to find the the colimation of the scope was dead on out of the box. A down side is that, while the tripod is pretty good (especially for the price), there was an extremely poor design decision when it came to the saddle that the scope rests in within the fork mount: it's plastic. In fact, it's pretty flimsy plastic. This coupled with the fact that the shaft that the saddle pivots on for the altitude axis has a good amount of slop in it means that there is substantial play in the alt axis. Even with the alt clutch completely locked down, the flex in the plastic saddle coupled with the play in the shaft translates to easily three to four degrees of slop. The azimuth axis, however, is rock solid. I started taking the fork apart, but after giving it some thought there's very little that can be done without replacing the plastic saddle completely, so I just live with it. In all honesty, this is the one thing about this scope that I really do not like. Let's move on to some positives. :) I've read lots of reviews for this and other DS line scopes from Meade where the writers complain of the inaccuracy of the Autostar. Out of the box, the computer control board (the piece in the mount that you plug everything in to) was flaky, resulting in a mostly non-functional autostar and lots of motor errors. A five minute phone call to meade with a description of the problems that I saw and meade immediately shipped me a replacement computer board and a replacement Autostar controller, no muss no fuss. (I am quite impressed with the Meade customer support. Even on a low end scope like this they seem to be very serious about satisfying their customers!). It wasn't until the new autostar and computer board arrived that I could figure out that the actual problem was the computer control board and not the handbox. In any even, back to the story... When it comes to aligning the autostar and then using it to find objects, I started with some disappointing results. I've realized now that this was mostly due to poorly written instructions for the home positioning with Autostar. If you have poor Autostar results on a DS scope, here's what I'd recommend: 1) Reset your scope 2) Calibrate the motors 3) Train the motors on Polaris or on some distant terrestrial target (I use a radio tower about three miles across the desert) 4) Make sure that the autostar is set up for Astronomical targets! (If you don't it wont track) 5) Take time to level your tripod! Here's where the instructions are lacking. It sounds like all you need to do is level the OTA. This is not true in my experience. The closer to dead level that you can get the TRIPOD, the better your autostar results will be. The DS-114 that I bought came with a small 1.25" combo level and compass. Of course, it's really only usable in the focuser if you're going to mount the OTA with the focuser vertical. Unfortunately, unless you're 8 feet tall, this just isn't practical for viewing. I personally prefer the focuser to be mounted horizontally on a newtonian unless I'm doing photography. To solve this problem (and because I've been too lazy thus far to go and get my four foot level) I simply sit the level on the flat piece of cast metal in the middle of the fork mount (just below the fork really). With it in this position, the OTA alignment has no impact on the bubble. Loosen the azimuth clutch and rotate the OTA to each of the legs in turn, making the adjustments to each leg as necessary to center the bubble. If you do a reasonable job, you should be able to rotate the OTA clear around with the bubble staying fairly centered. At this point, the tripod is level. Don't kick it moving around the scope! 6) Level the OTA. To do this, I just sit the little level on each end of the OTA and adjust as necessary. Don't go crazy trying to center the bubble in all axes!! Remember, the tripod is already level. As long as the bubble is centered with respect to the altitude axis you are set. Lock the alt clutch. 7) Find north and point the OTA at north. Someone at Meade definitely has a mean sense of humor. It took me three days to figure out why my alignment starts were always five or more degrees off target from the azimuth axis. The little 1.25" compass/level that they give you is pretty sensitive. When I level my tube and lock the clutch, I would typically leave the compass sitting on the end of the OTA and rotate around to north. Now, I should also mention that I'm living in a new city 10 degrees further south and my northern sky is almost completely washed out with light pollution, so I was puzzled at first that the compass seemed to point five to ten degrees east of where I though North was. I thought I could just barely make out Polaris, but the unfamiliar sky was so washed out I figured I just had the wrong star and went with what the compass told me. There is a subtle engineering flaw here, though, that is conspiring to mess up your alignment. If you have a DS scope handy, take your compass and stick it on the end of the OTA and stand back. What's wrong with this picture?? Yes, that's right! The altitude DC motor is sitting to the east side of the OTA! "So what?" you ask. Well, what's INSIDE of DC motors? Yes, you've guessed it! Magnets!!! The little compass that they ship is sensitive enough that the DC motor actuall pulls it a few degrees to the east. The pull isn't so strong that it will pin the needle, though, so the further east you turn the OTA, the more resistance the needle has trying to reconcile north. This tends to land you five to ten degrees east of magnetic north. THIS WILL ALWAYS MESS UP YOUR ALIGNMENTS!! The answer, of course, is to target polaris before leveling the OTA, lock the azimuth clutch and then level the OTA, locking the altitude clutch. Having taken these steps and special care not to touch the OTA at all for fear of the three to four degrees of play in the altitude adjustment, I usually let Autostar pick two alignment stars and use a Meade 18mm WA objective to center. I find that the initial alignment is usually off by about 2 degrees total. Once these stars are centered and alignment is completed, however, the DS Autostar system comes into its own. Now that I've worked out a system for doing the alignment (which takes me about three minutes or so), I spent some time tonight working through the "Tonight's Best" tour. I spent about an hour going through approximately twenty to thirty objects. In EVERY case, the object was visible within the FOV. For some objects (dumbbell nebula for instance), the object was on the extreme edge of the FOV, but it was still there. For many objects (Mars, M31, several open clusters, etc) they were dead in the center. One other tip. I've noticed an annoying "feature" of the autostar. I can't find anything to confirm this so it's only speculation, but here's what I see and here's how I fix it: When you slew to an object that is on the edge or not in the FOV at all and you need to recenter it, the motors will sit silent for a second or two after you center and then reengage. In the process of spinning up, they usually move the object about halfway to the edge of the FOV (or completely out with a 9mm or 5mm). My first tactic was simply to overcorrect in the opposite direction and then let the object slide back to the center. This works great... for about thirty seconds. After thirty seconds or so the autostar seems to act as though you have "temporarily" moved the scope and it begins to slowly drift back to the original incorrect alignment. Not exactly the same place, but it definitely stops tracking. As you can imagine, this is irritating. My fix for this is to center the object in the FOV and then press and hold enter for two seconds. When you release, you will be prompted to center and then hit enter to sync. Verify that you are still centered and then hit enter. Now the scope will track the object accurately. I did this with M31 last night and left the scope for about two hours to allow M31 to rise a bit higher. When I returned to the scope two hours later, M31 was still centered in the FOV. Now, I can't say it was exactly where it was before, but hey, for $200, that's not bad at all. All in all, this is an excellent scope for a beginner, though the autostar can lead to significant frustration unless the person is going to spend time understanding how it functions. Once the alignment is understood, it can be used by beginners to easily locate some interesting stuff. On the other hand, the scope is perfectly usable without the GoTo function. The one MUST HAVE addition for this scope is the electronic focuser, IMHO. The altitude slop is so bad that simply trying to rotate the focuser by hand will throw you way off, not to mention the difficulty of determining whether or not an object that is shooting in and out of the FOV in your 9mm objective is actually in focus. The electronic focuser makes this much much easier. Best regards ---------------------------------- David Hoelzer Cyber-Defense.org http://www.cyber-defense.org/CV.html
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