I don't know everything, but I am in the middle of reading a thread about Refractor or Reflector, they talked about heat and mirrors, I mean they go down to if they touched there dob tube with their bare hand they could see the waves of heat in the dob tube, they wear gloves so that doesn't happen, metal tubes were the worst.
You cannot heat your mirror or your secondary because it will show up in your eyepiece, heat coming off the mirror will look like heat coming off the freeway on a hot day and make the object your trying to look at dance.
I am the happy new owner of a 12" truss rod dob and wondering about whether or not I need to heat my mirrors, especially since I lack the protection of a traditional tube dob.
These dobs I have come with a fan to Cool the mirror down, intended to get it to operating temperature sooner, but I'm guessing that there's a good reason to have it actually stay a few degrees above ambient, when theres condensation happening around you.
How do you usually heat your dob? Mine comes in a metal box rather than the typical plywood or mdf boxes that the mirrors usually go in. I'm thinking that some kind of heat tape attached to the metal box may be the ticket.
This S&T article seems to have ideas. What have you tried and what worked well for you? Particular dew heater strap tech for dobs?
I myself am a newbie, I have a model airplane heater to keep my Telrad dry so I can find things, I have used it once to dry off the primary mirror because of my mirror cover, and a few times on the secondary mirror, when I look thru the eyepiece things are dancing and I go inside for a little while.
Edited by Waynosworld, 27 November 2020 - 11:54 PM.