[AZ-Observing] Tropical Moisture and Dew


We had our problems Saturday at Las Cienegas with dew as well, and it
took its usual toll of unprepared Arizona observers.  Fortunately I had
anticipated, the recent rain and moisture had brought back memories of
my 18" dripping with dew a couple years back atop Mingus Mtn, unable to
enjoy otherwise perfect skies.

This time I prepared!  A bit of perfboard loaded with power resistors to
form a heating element and the smallest 12V fan I could find assembled
into a scrap tube of machined aluminum.  I built the heater subassembly
Friday and finished it Saturday afternoon.  Connect to one of the 12V
sealed lead-acid batteries I keep around and presto!  A dew devil!

In the end it proved unnecessary for my 18", 40 pound mirrors do not
cool off all that easily and dew never touched my primary or even the
secondary inside the cage and shroud, Deep Violet was functional when
Mercury rose in the sunrise.  But I was lending my dew devil out left
and right to clear SCT corrector plates that seemed much more vulnerable.

Andrew


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Andrew Cooper
Tucson, AZ
mailto:acooper@xxxxxxxxx
http://www.whitethornhouse.com
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