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View Full Version here: : Dew controller for 14inch SCT


thunderchildobs
04-11-2009, 08:21 PM
I am looking for recommendations for a dew controller /heaters that would be suitable for a Meade 14inch ACF SCT.

Ideally it should be able to run from mains power as it will only be used in an observatory.

Brendan

(PS my 12inch classic LX200 is being advertised for sale in the classified section)

mtodman
05-11-2009, 01:17 PM
Hi Brendan,
A 14" corrector will take a fair bit of heating / power. I would suggest that you go with something like the Kendrick ZapCap from Bintel. I don't know if you really need a dew controller to go with it though. I run mine directly from 12V supply with no problems.
For 12v power, I have converted an old PC Power Supply as shown in the attached link:
http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply

multiweb
05-11-2009, 01:31 PM
Start getting a flocked dew shield that runs the length of your OTA past the corrector cell and you'll find that you'll have to warm up the corrector plate very little or even not at all.

mithrandir
05-11-2009, 02:25 PM
I asked about a ZapCap for my SCT. Because I have two dovetails on it, the shield would have to pass over one of them. You can't cut a slot for the second one because the heater is too close to the edge of the shield.

Marc seems to be on the right track. I have an Orion shield with length about 1.5 times the tube diameter and haven't seen much dew form even without a heater.