Dew :(

[hornedreaper33]

Happy Friday everyone!

Last night I was having a battle with dew. I had my dew strap turned up for the first 20 minutes while I was setting up and I noticed that the wire was pretty warm (Astrozap heater). After that I turned it down and lost the battle to the dew

I have never noticed the heater wire get warm before. Is this normal when you have the heater turned up to 11?

I think I'm going to be moving to a mains supply as my 8Ah lipo is getting wiped out in a couple of hours. Pocket Powerbox seems like a solid choice. 

[wuthton]

If you're running 240v to your mount then I'd highly recommend one of these.  Neat, convenient and reasonably safe. 

https://www.screwfix.com/p/masterplug-weatherproof-box-kit/46169

 

[StuartJPP]

How deep is your dew shield?

Mine is about 25cm deep on a 125mm objective lens and my dew heater is barely warm to the touch, it will keep the dew (and frost) at bay for an entire evening drawing about 3 watts (0.25 amps).

You only have to keep the air above the mirror/objective above the dew point, not burn it off 😁

[hornedreaper33]

The dew shield is the great big Celestron one for the C8. To be honest I'm asking a lot of my set up as it's been raining for two weeks. It's ridiculously humid here. I just need mains power on my dew heater so I have the ability to keep it cranked up. 

[kirkster501]

An active (i.e. heated) dew shield or tape should never be "warm" as such.  It only needs to output the tiniest, weeniest bit of warmth to keep the dew off.  Indeed, if your tape or shield element is actually warm to the touch it will be having adverse effects on the seeing, especially a SCT scope.