MEADE IMPROVEMENTS: OTHER
Drive The drive simply did not always work, and when it did work it did not turn the scope with the correct rate. After taking it apart, I found that the optical encoder was trimmed by using tipex (or a comparable substance). The problem was that the substance was so thick that it kept the encoder from turning if it was stopped at the wrong place. This happened about 2 out of 3 times and one had to shake and switch on/off repeatedly to get it working again (for some time). The solution was simple, I carefully removed some of the substance, without exposing additional gates. After that, it worked just fine.
Tube After I finished with some of the other improvements, the tube showed a bit of abuse. So it was improved in two ways, it is 'harder' now, and it has a different color. The main objection against a paper tube is its relative softness. Especially at the mounting holes. After removing the outer white layer, the exposed paper was impregnated with epoxy. Then it was sanded and painted red. (Actually it was repeatedly sanded and epoxied to achieve a smooth surface.) I don't like white, it is a bit to white when my eyes are fully dark adapted. This has probably to do with the fact that it doesn't get 'really' dark here.
Focuser I disliked the feel of the focuser from the start. But after I saw how much it sagged when a camera was attached, I decided to exchange it. It would have been preferable to replace it by a 2" focuser, but I had a 1.5" NFG-2 at hand. So I used that one. This does cause vignetting for photographic use.
The secondary was to small, it only allowed me to use about 9" from the 10" mirror. Since the original focuser had the focal point quite far above the tube (just over 13 cm or 5" !!) I decided to move the focuser up the tube. This fixed the problem for visual use, but photographic use will have strong vignetting, unless I mask a part of the primary. After measuring my camera/focuser combination I also changed the mounting holes for the "imaging" position of the primary.
Backend The backend was completely open. It was possible to look through the focuser, in the secondary and then past the primary. This is not acceptable since it also allows light in the reverse direction to reach the focal plane and lessen the contrast. The solution is simple, mount a ring on the backend that allows air to pass through (in the middle) and blocks all light between the mirror and tube. Due to the recent (Jan 99) discussion on the ATM mailing list I will be adding a fan as well.
Tube inside The inside of the tube was just black. There are no baffles installed. After seeing (by daylight) how much the reflections in the tube could be lessened by black velvet, I lined the whole inside of the tube with it.
Finder The Meade comes with a fixed focus finder. I had another (cheap) finder lying around that fitted in the same mount. A simple change, but much easier on my eyes afterwards. I also mounted