Strip Dew Heater For a Celestron 6SE reflector

[yeletah]

Hi

I'm thinking of buying a Astro zap £69 Heater + 6" strip £35 to prevent dew.

is it a good investment?

Is the cheaper HitecAstro  heater £39 just as good for a 6SE?

Thanks for any advice.

Steve

[DaveGarland]

I cant speak for the HitecAstro one Steve but I have an Astro Zap and find it very effective. I use a separate power pack so I dont lose any life from the scope one, you can get a cheap one from Maplins. It may be that the cheaper strap is perfectly effective though.

Dave.

[emadmoussa]

Hi Steve,

Do you mean Celestron Schmidt Cassegrain 6 inch - not reflector?

If so, like you know SCTs are dew magnets. I remember my C11 could suck all the dew in the garden in under 30 minutes. I used only a dew shield which lasted for about 3 hours. If you intend on spending more time outside especially in those humid condition, then yes, a dew heater is necessary.

I would suggest, however, that you invest in a dew controller that has more than 1 port just in case you want to use another heat strap for, say, finder scope or telrad..

[Tinker1947]

If you have a stable 12v supply one these works very well i drop the voltage to around 5 volts on a ST80 its clear all night, the volt meters bit of over kill only really needs the output.....source from E-bay very cheap....

[LukeSkywatcher]

I have the Hitec astro controller for my 8se and it works fine. It has 2 ports on it for 2 heater straps if you want to add another but one should be enough.

[yeletah]

Thanks for the great repsonse, I will buy buy a dual port hitec astro for my Schmidt Cassegrain 6 inch and a 6" strap.

Is it best to place it just behind the dew sheild?

Thanks

Steve

[emadmoussa]

I would think it'll be more effective underneath the dew shield  as close as possible to the corrector.

[LukeSkywatcher]

Just behind the corrector plate. It should be making contact with the metal of the scope.

[keithatrochdale]

Dew heaters are also available on e-bay.

http://www.ebay.co.uk/itm/W-W-Astro-dew-heater-80-cm-for-8-telescope-/190914219212?pt=LH_DefaultDomain_3&hash=item2c735fcccc

Very fast service, looks good, yet to be used in anger though.

Dimmers, but a little wait as they come from Hong Kong

http://www.ebay.co.uk/itm/DC-12V-8A-LED-Light-Dimmer-Brightness-Adjustable-Bright-Controller-Single-Color-/140928585939?pt=UK_DIY_Material_Electrical_Fittings_MJ&hash=item20cfff90d3

[Tinker1947]

Just ordered a 12" from FLO for my C11, already have 2 of the dimmers .......think it was  10 days from Hong Kong, but they work ok....

[keithatrochdale]

My dew strap for my C11 from the e-bay supplier above was only £27.60 with free P&P arrived in just over 24 hours.

[hobsey]

Just a word of warning about the Hitecastro contoller. The terminals are quite sunk in on my controller and give quite a loose connection to the heater strip.

I have already dismantled it to see if I can do anything about it.

Options are, take a demel tool to the case and widen the holes so I can push the heater strip terminals further down or try and unstick the circuit board without damaging it and moving it further up and resticking it.

[jonathan]

I have the AstroZap four port controller but one half of it failed, not economical to post back for repair so it has become a single channel / two tape heater controller.  Never was too sure how well it worked, my scope still seemed to dew up as I wasn't sure how high to turn up the knobs.

I bought the HitechAstro four channel, four port controller as a replacement which I have yet to use with my 8SE, but as it also comes with 12V outputs I should need one less battery port (for the scope power).

[yeletah]

Hard to fit celestron 6se branded dew cover over heat strip? unless loose and cone shaped (wide around corrector plate)

tried strip next to metal, behind corrector plate, slight dew inside of glass?

any ideas?