From: "Jerry B. Hillman" 
To: 
Reply-To: "Jerry B. Hillman" 


Hi all,
I am encouraged by tonights star test results.  It wasn't perfect but I now
have a good idea of what is wrong.
I started by doing a Ronchi test on Arcturus.  I set it to show seven
lines. Although I had to chase the image a couple of times I did see that
the ends of the lines have a slight hook. Otherwise, they seemed to be
perfectly straight and  evenly spaced. Okay, first problem identified.  I
have TDE. That, I think I can fix.
Next I did a star test using my highest power eyepiece.  3.6 mm.  This
gives me almost 500x.  I would prefer higher but, that's life.  Outside of
focus I started where I could see a fairly large image.  My secondary
shadow was nicely centered. The image itself was a bright fuzzy ring
enclosing a series of not so bright rings  Rings within rings within rings.
The entire image was almost perfectly round.  As I moved closer to focus
the image shrinked, I had fewer rings and the image became somewhat oblong.
 When I got the image down to where I had only the bright ring and about 4
or 5 inner rings the image was becoming a little triangular. I moved inside
of focus to check and it did turn 90 degrees. I moved back outside of focus
and turned my primary mirror in the cell about 1/4 of a turn.  The image
became more oblong than triangular.  I turned the mirror another 10 degrees
and I still had an oblong, but it hadn't changed position. Okay, another
problem identified.  My mirror cell definitely has to be rebuilt into a
flotation cell.  I intended to do that anyway, but didn't have time to do
it today. In the image, isn't the bright, fuzzy outer ring being caused by
the TDE?? I hope so.  If not, please, someone tell me.  I already
determined that the center zones of mirror were still a little on the
spherical side this morning with the Ronchi test.  I tweaked it a little. 
Based on the star Ronchi test, I think I better leave it alone for now, and
just worry about the edge.
Now I am going to go and just look through it and see what I can see.
Jupiter looks nice at 100x and pretty good at 200x.  I am going to see what
else I can find.
Clear skies, Jerry

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