Re: To cut or not to cut?

groski@esvax.dnet.dupont.com
Mon, 3 Apr 95 14:15:11 EDT

With all the talk about mirror cells and diagonal holders, I thought I pass this improvement on. I have a 13.1" Coulter that I purchased a few years back. As an avid ATM with a growing family I didn't have time to build a light bucket so I thought I buy this one and fix it up along the way. I've done the usual things that one does, new focuser, Telrad etc. Well the image was OK but it showed some astigmatism at high power. The mirror needed cleaning so I removed the mirror from the cell and found it to be supported on three foam pads, also it looked like one of the aligned bolts may have been touching the back of the mirror. I shorten the bolts, and replaced the foam pads with some bubble wrap. To my delight the astigmatism was gone and a star test now shows a much better figure. The planets now show a nice amount of detail. I also tested the mirror when it was out of the cell. The figure was pretty good, and my reading show that it is just under 1/4, which is what the star test is now showing.

Dave Groski