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Re: The Refrigerator



On Fri, 23 Oct 1998 16:53:37 -0500, Tom Droege <droege@wwa.com> wrote:
*>
*>I note that I could match this $200 (plus shipping) refrigerator with 4
*>small thermoelectric (@ $10ea) devices.  I am thinking of just plastering
*>some TEC on the frame of the telescope.  There is lots of area, and warming
*>the whole telescope body would reduce problems with dew.  Serious
*>astronomers will be horrified that I am thinking of heating the telescope.
*>But we need only 7 second seeing.  Should be hard to do this much damage by
*>heating things up a few degrees.   
*>
*>Just waiting for the screams of horror.
*>
*>Tom Droege

In the amateur astronomy world, there is a company that produces a variety
of HEATING products for telescopes. THese use resistive heating to
heat eyepieces, optical windows (corrector plates), finders. FOr instance,
my Princeton club's Celestron C-14 has a dew shield that draws FOUR AMPS
at 12 volts (!). In the amateur world, the reduced seeing due to any
small change in optics or distortions in the air is FAR PREFERABLE to
the accumulation of dew which will "reduce" seeing to ZERO.

Seven arc second seeing is pretty lowsy seeing: I wonder what Jupiter would
look like under those condtions: Jupiter is a kind of "calibration object"
among amateurs when estimating seeing

Herb Johnson
Herbert R. Johnson              http://pluto.njcc.com/~hjohnson
hjohnson@pluto.njcc.com         voice 609-771-1503, New Jersey USA

             amateur astronomer and astro-tour guide
     classic S-100 computers restoration & parts as "Dr. S-100"
   rebuilder/reseller of classic Macs for your computing pleasure
          and senior engineer at Astro Imaging Systems