From: Mark Holm 
To: atm{at}shore.net
Reply-To: Mark Holm 


One observation about Yolos:

Art Leonard's Yolos were built with rather tightly enclosed box like
"tubes" with lots of baffels inside and a long baffeled
"snout" in front.  This undountably helped the stray light
problem that the design would suffer from otherwise, but probably caused
rather serious trouble from tube currents. Knowing the lessons taught ATM's
by Brian Greer and Alan Adler, one would now insist that a Yolo tube have
exhaust fans, and fans blowing across each mirror face.  It might even be
wise to have an exhaust plenum running the length of the
tube, with inlet openings between each set of baffels to suck up
heterothermal air and keep it out of the light path.

A couple of other notes:

Art Leonard also designed an original three mirror unobstructed telescope
which he called the Solano.  I have seen very little about this scope.  Art
Published a booklet about it, similar to what he did for the Yolo, but I
never got a copy.
   Evidently, copies of the Solano booklet are even rarer than copies of the
Yolo booklet.  If you ever come across one, please let me know.  If it is
not copyright protected, or if I can get permission from the copyright
holder, I would like to make a web version of that also.

The names Yolo and Solano might seem a bit unusual to many.  They are the
names of two California counties, near San Fransisco.  Evidently Art was
quite fond of
these two counties and chose to name his telescope designs after them.  If
you do a web search on either name, you will find much more about the
counties than about telescopes.

Mark Holm

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