Dew Heater for Explorer 130PM

[bandit]

Managed to get a few mins in the company of Saturn before frost on the lens and condensation on the tube set in last few nights.

I've been looking at Dew Heaters and tapes but not sure which is the correct one for my explorer 130PM or even how to attach these to the scope.

I can see plenty of makes and models, but haven't been able to find any examples of how they are attached to the scope or what make/model is best for my scope. Would appreciate the words of wisdom from those that have trodden this path before please.

regards,

Bandit

[gary1968]

Howdy Bandit,

Just a question, was it the primary, secondary or ep that dewed / froze over?

There is a guy on here that makes bespoke heaters to order, it might be worth dropping him a pm.....

See here...... http://stargazerslounge.com/index.php/topic,32420.0.html

Hope that helps,

Gary

[bandit]

Thanks Gary, it was the primary mirror, as the worst effected, but also the outside of the tube that got a little frosty (not to mention my fingers). Not surprising at -3 i guess, but the clear skies were worth it I'll follow the links, much appreciated.

Bandit

[stefski]

Hi Bandit,

I'll second that from Gary.

I've got one of 'Blinky's Bespoke Dew heaters' from this forum....It does exactly what it says on the tin - and cheap too! Just give him your dimensions!

Stef

[beamer3.6m]

Do you have a dew shield wich you can make for about £3.00 from a camping roll mat.

Just make the dew shield about 2.5x the D of your scope so 5" = 12.5cm dew shield - although probably 15cm to allow it to slide onto the scope.

This will save you a lot of dew problems and it a really cheap way to solve the problem.

[daz]

Frost on the tube is not a problem, but I'm surprised that the primary was worse affected than the secondary...?

[scotastro]

Amazed you had problems -

The tube of a Newtonian acts as a dew shield for the optics so even at cold temperatures the optics should be ok. I regularly observe at temperatures down to -5^oC over the winter.

Make sure you breath down away from the eyepiece when observing. Also keep you EPs with the caps on in a pocket not on the accessories tray as they get cold and dew up quickly that way.

Also don't leave a scope pointing straight up when looking at a chart to see what to observe next move the scope to a shallow angle as it stops the dew going down the front.

A 12v hairdryer is a cheap way to remove any dew you do get on an EP.

Mike