Dew Heaters

[JohnH]

Grr,

I keep getting my astro shots lost to dew. I guess the problem will be around for the whole of winter so I want to do something about it.

Sorry if this has been covered before but what solutions are you using out there? Are you happy? Should I buy or build? I need to keep a 90mm OTA and a 58mm camera lens fog free and a passive shield is not enough...

[RAJAH235]

Hi JohnH. Peruse these for a start. May be a help.
L.
(http://www.saao.ac.za/~wpk/atm.html)
(www.efn.org/~mbartels/)
(http://www3.sympatico.ca/mark.kaye/dewheat.htm)
(http://www.dewbuster.com/heaters/heaters.html)

[gbeal]

Hi John,
I built and bought, so can help either way.
Buying? I used Scopestuff in the US, and bought a couple of their smaller 3" heaters.
Rob Beck, better known as "Robby" made my controller, but the Kendrick or similar are good as well. (I was just frugal).
I also made a heated strip for a 7" Mak/Newt, from nichrome wire, the correct thickness/length.
Whichever way you go, the use of a heater is almost necessary sometimes, and once used is a revelation.
Gary