Dew control for a 130PDS

[rnobleeddy]

After an imaging session last night I noticed that I was probably close to having enough dew on the main mirror to start to cause issues with images. I presume it's only going to get worse as we get into winter.

I assumed I would need some heater straps so picked up a 2nd hand dew heater controller a couple of months back, but don't have any heaters yet. I've also seen dew shields that I presume I can make myself, but not sure what combination I'm likely to need.

Anyone got experience with a similar scope?

Assuming I need heaters, am I going to find anything cheaper than those sold by FLO?  My controller can handle 2 heaters. I also have some spare powered USB ports that I can use if the USB heaters work well.

[NGC 1502]

FLO only sell good kit and give top service so it may be best to go with them...

A dew shield made from camping mat foam helps, especially if the secondary mirror is not far down the tube. When my Newtonian secondary dews up I point a 12v dew gun down the focuser.  Having removed the eyepiece I rack the focuser fully in so the gun is a bit closer to the secondary.   That often lasts for half an hour or so.  Don’t leave it until the secondary has globs of moisture, do it as soon as it’s gone misty.

The primary dewing up happens less as it’s much better protected. On my Dob I increased mirror ventilation, that also helps with cooldown.  Many use a fan for cooldown, that also promotes air flow reducing the tendency for dew to form.

You’ve already considered heaters, that could be added to the above precautions.

Ed.

[rnobleeddy]

12 hours ago, NGC 1502 said:

FLO only sell good kit and give top service so it may be best to go with them...

A dew shield made from camping mat foam helps, especially if the secondary mirror is not far down the tube. When my Newtonian secondary dews up I point a 12v dew gun down the focuser.  Having removed the eyepiece I rack the focuser fully in so the gun is a bit closer to the secondary.   That often lasts for half an hour or so.  Don’t leave it until the secondary has globs of moisture, do it as soon as it’s gone misty.

The primary dewing up happens less as it’s much better protected. On my Dob I increased mirror ventilation, that also helps with cooldown.  Many use a fan for cooldown, that also promotes air flow reducing the tendency for dew to form.

You’ve already considered heaters, that could be added to the above precautions.

Ed.

Thanks. Should have pointed out I'm imaging so ideally want to sit inside and control things, or even better, set off a sequence and watch TV! So I really want something that works in the steady state, especially as I'm actually looking forward to it getting darker as we go in to winter this year! 

I'll make a dew shield and see how that goes. 

Totally agree that everything FLO sell has been excellent - just wanted to check what else was on offer before dropping ~£130 on stuff I might not need! 

[NGC 1502]

 

1 hour ago, rnobleeddy said:

Thanks. Should have pointed out I'm imaging so ideally want to sit inside and control things, or even better, set off a sequence and watch TV! 

Totally agree that everything FLO sell has been excellent - just wanted to check what else was on offer before dropping ~£130 on stuff I might not need! 

 

Don’t blame you, we all look at the price, but I’ve just recalled that FLO do a price match, they have that on the home page 👍 You want to sit inside and control things and watch TV ?   Sorry mate, it only counts if you’re frozen &. fed up not to mention totally cheesed off that everything is going wrong 😁😁

Cheers from Ed.

Edited September 21, 2020 by NGC 1502
Correction