Hair dryer for dew control in reflector

[StarLane]

I`m wondering if anyone can tell me where I can buy a small battery powered hair dryer to prevent dew from forming on my secondary??

I have been to a local camp shop and all they have is 12volt hair dryers. When I am viewing, the car is usually too far away to enable me to use it in the cigarette lighter socket and I don`t have a 12volt battery pack and I`m trying to aviod buying one.

Ultimately I want a small dryer that takes regular batteries or rechargeable NI-Cads or Nikel Metal Hydride batteries.
Where can I find one of these??????
I have read posts in the past of people using hair dryers for this purpose. Where did they get them?

Any info would be greatly appreciated. :)
Cheers.

[iceman]

Most people that use them, use the 12V ones that you get from camping stores.

You really should just buy a jumpstarter battery pack from autopro or a similar auto shop. You can get them for around $40 and will easily support running the hairdryer when required all night.

[Dennis]

Hi StarLane

Another option might be to prevent the build up of dew in the first instance, by using a secondary mirror dew prevention heater, such as the Kendrick system (http://www.kendrickastro.com/astro/dewremoverphotos.html).

You will still need a battery with some grunt, but you'll be trickling the current all night to keep the secondary above the dew point, rather than belting it with the heat from the hair dyer once it has dewed up.

Cheers

Dennis

[Starkler]

This is precisely what you need (http://www.astrosystems.biz/dewgrd.htm)

12V hairdryers dont pack much of a punch and mine at 18A current drain will kill anything smaller than a car battery pretty quickly.

Other options are an ota tube extension dew shield or many report than running a fan pushing air up the tube is enough to keep dew away.

[StarLane]

Thanks guys,

Didn`t realise mirror heaters were available.
Now I need to think about which way to go.

Cheers, Paul.

[rogerg]

I have one of the 12v camping ones and am very cautious about using it. I only use it for short bursts (5 seconds or so) and not for more than a handful of bursts either. I know it could kill a SLA with the high draw. So I wouldn't really recommend one, but I don't have a better option for you. I'm always suspicious of heating up things with the dew heaters, but do have a low powered DIY one on my 12" corrector plate.

Roger.