Fight against dew for newbie

[long_arms]

Hello,

Last night I had the best night stargazing I've had so far (I got my scope a month or so ago).

But I stopped before the orion nebula had risen high enough for me because my primary had completely dewed up.

I don't have any dew strips/fans etc.

Is there anything I can do tonight to clear dew without having to buy anything? Wrap something around the ota? Heard something about using hair dryer?

Cheers,

Dan

[Xplode]

A hair dryer would probably work fine.

I guess you have a newtonian? They should take a while before the primary dews over and the secondary will dew over long before the primary.

[long_arms]

Yes I have a 200p newtonian.

Everything just got horribly dewed up, when I brought it in it was the primary that I was surprised about the most though.

What options are there for dealing with dew on the secondary?

[onesmallstep]

Hi

Buy a foam camping mat and cut to size, wrap around the top of the OTA and tape the foam so that it retains the tube shape.

HTH!

[billhinge]

Like you when I bought my SCT I didn't want to spend anything not observing related e.g eyepieces etc , but living in a high dew area (80% to 100%) I gave in eventually

(I sold a load of unwanted stuff on ebay and amazon to part fund cost)

So I bought:

Dew shield/heater (Astrozap Flexible Dew Shield £39-110)

Dew shield controller (Astrozap Dual Channel Dew Heater Controller - £69)

Mains power supply unit (something from Maplin)

Mains power cable (long caravan style cable from amazon) plus assorted connectors

waterproof box to put power supply unit in (£20 from amazon)

RCD plug (few £ from amazon)

The Astrozap products are superb (also got heater tape for finder/eyepiece)

It really depends on your pain threshold, get a hairdryer and keep drying or get a heated dew shield and forget the hassle (you wont regret it investment wise)

[long_arms]

Thanks for the replies !!

yes the humidity at the moment is awful! Tonight its going to be 87% and rising all night.

I have a camping mat that I'm going to cut up now but I think I will have to get some heated dew shield/strips at some point.

Once I've sorted out some sort of power for the heq5 I can then start buying things like that.

Thanks so much for your responses.

Dan

[Capricorn]

You cannot prevent dew from forming on your scope, you can reduce it but eliminating completely it will not happen.

Does seem odd that people spend time, money and effort in geting the temperature of a mirror down using fans, then use a 12v hairdryer warming it up to remove moisture on it. :D :D

[VigdisVZ]

You can make both DIY battery tanks and dew heaters if you're a bit handy with electric stuff. A simple camping mat will still help a bit in the meantime.

[long_arms]

Haha it does seem quite counterintuitive to warm everything up!

I would love to make a diy battery tank and dew heaters. I'm only 20 so trying to learn as quickly as possible atm. A year ago I never imagined astronomy got so complicated haha!!

Any good online tutorials?

The camping mat will help drown out this pesky streetlight for now also.

[Marc1980]

From everthing I have read on here leisure batteries are definately the way to go. If you feel like trying your hand at a diy project check these links out of others who have built their own power tanks. I am gonna go down this route when i have something to plug it into.

Or you might find this useful.

[VigdisVZ]

Here's some more stuff to look at for DIY battery and heat.

http://myastroimages.com/Equipment/Telescope_Field_Battery_DIY/index.php

http://www.iceinspace.com.au/63-292-0-0-1-0.html

[Russe]

Are there battery run hair dryers?

[starnut]

Are there battery run hair dryers?

yes 12 volt

[Russe]

Can you recommend one? Loads out there with rubbish & good reviews. Very confusing.

On amazon I found one for 16£. Would that be in the ballpark?