Dew Stopper/Heater

[mjbent]

Hello - since the colder/winter months are coming quickly here in Canada, I just thought I'd ask about dew heaters or dew stoppers - forgive me, I don't know the actual term for them. The heaters for the mirror to prevent dew/frost accumulation. Basically I wondered about when I would need it (at what temps), and what kind to buy etc. I have a 10" dob. Any help is appreciated! Thanks!

[oldannie]

glad you posted this question - we have an 8" Dob which we had out for the first time last night when it was very cold and within a  short time  it was streaming with water so we're looking for similar advice!

Cheers

Annie

[faulksy]

hi both, you can heaters for the secondary mirror and primary but the primary is usualy ok, for the secondary you can get temperature controlled automaticaly or plug in to a controller. some people just wrap a eye piece heater around the stork and plug into a controller or you can make your own like i did. or what a lot do is use a simple 12v hair dryer and give the mirrors/eye pieces a blast when you need to, some thing like this

http://www.firstlightoptics.com/dew-prevention/hitecastro-four-channel-four-port-dew-controller.html

to control

http://www.firstlightoptics.com/dew-prevention/astrozap-dew-heater-tapes.html

for your eye pieces and finder

hope this helps

[Owmuchonomy]

Great dew bands are made in Canada - Kendrick, I own 2. It's not temperature that should concern you but the dew point measurement. The new 'Clear Outside' forecast provided by the Sponsors of this forum, FLO, quotes the dew point at your location. Not sure if it works outside the UK.

[sluce]

Glad you asked. I was out last night and the temps dropped into the 20's. Im just a little south of Canada in North Dakota. Pretty quickly everything was covered in frost. A hair dryer and a towel bought me some time but before long i was frosting up again.