[Chaos-l] dew prevention advice

[Mark Lerch]

Michael,

I have made my own heaters according to those instructions, since I own the DewBuster.  They are easy to make, and I'm not especially experienced with soldering.  I wasn't able to put them in a nice home though (cloth with velcro, e.g.) since I don't (and won't) sew, so I don't really use what I've made.  But it was a fun project.

I love the DewBuster!  This is one of my all time favorite pieces of equipment.  The reason is it works off the ambient temperature, so it draws extremely low amounts of current.  Running multiple heaters all night off a jump start battery leaves plenty of juice in the morning.  You can control how many degrees above ambient you want your heaters to run, so there is no danger of getting any kind of warm current issues either, with imaging for example.

I highly recommend the DewBuster.  Ron is also outstanding when it comes to service.  I think everyone ought to get one.  Why not be left with as much battery as possible in the field?

Mark

-----Original Message-----
From: chaos-l-bounces at rtpnet.org [mailto:chaos-l-bounces at rtpnet.org] On Behalf Of Michael Hrivnak
Sent: Monday, November 03, 2008 6:25 PM
To: chaos
Subject: [Chaos-l] dew prevention advice

It's time for me to buy some dew prevention for my Starmaster 18.

First off, I am strongly considering building my own heating elements by following these instructions:

http://www.dewbuster.com/heaters/heaters.html

Rather than lay out $120-150 on heating elements, I think I can do it all for under $20.  Have any of you done this before?  Would anyone be interested in making some with me?  The resistors are real stinking cheap ($0.016), and shipping is really the greater cost (at about $5 for as many as you can buy).

As for a controller unit, what do you suggest?  Lots of people praise the DewBuster for its intelligent thermostat, but I'll mostly not be using that feature.  On the Starmaster, I'll just use it to heat the finder, telrad, eyepiece, and secondary mirror (which already has an AstroSystems heater that includes a thermostat).  However, I may want to use it on my refractor down the road, in which case the thermostat ability would come in handy.  Any opinions or experience to share?

Thanks,
Michael