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Best dew heaters for eyepieces?

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#1 Daniel Guzas

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Posted 26 January 2013 - 03:08 PM

Hello,

I have read here on CN'S that Dew not heaters are pretty good. But Kendrick gets good reviews as well. I need a pair of dew heaters to assist my eyepieces in a binoviewer in the cold.

I currently have a Kendrick controller with a spare port. One is being used to power the Kendrick dew heaters in my Wood Wonders eyepiece case.

Can I use the Dew Not's with the Kendrick controller? And if so are these as good as the Kendrick's? The former are much more expensive but want to know if they are worth the extra $$. AKA, you get what you pay for...

What are your opinions/experiences?

Thanks in advance.... And clear skies!

#2 Fred1

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Posted 26 January 2013 - 03:34 PM

The Kendricks are built better. They have cables and heating elements that are much more pliable in the cold and better RCA connectors. If you observe in sub-freezing temps and into the teens, I'd say go with the Kendricks, otherwise the Dew-Nots are fine. I have both. However, DewNot will do custom lengths and widths, if that's important.
And yes, the DewNots heaters are compatible with the Kendrick 12V controllers.

#3 Daniel Guzas

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Posted 26 January 2013 - 04:41 PM

Sub freezing temperatures are what I do a lot. This is an important consideration I didn't think of, whether the cables were going to get really stiff...

So Kendrick cables are better on the cold?

Thanks for the advice...

#4 Fred1

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Posted 26 January 2013 - 05:48 PM

Yes, Kendrick claims they are cold flexible down to -40. I can't attest to it as I haven't been observing in less than +13°F.

#5 zippeee

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Posted 26 January 2013 - 05:58 PM

Yes, Kendrick claims they are cold flexible down to -40. I can't attest to it as I haven't been observing in less than +13°F.


Agreed, I have a bunch of Premier heaters. I can't confirm -40 but I'm regularly out in -20c and the silicone is still soft. I don't think the actual casing of the conductors is silicone but the outer sheathing is.

#6 Daniel Guzas

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Posted 27 January 2013 - 01:10 AM

Perfect! Thanks for the confirmation. I think I will go with the Kendrick's!

Thanks again!

#7 AstroGabe

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Posted 27 January 2013 - 02:11 AM

I recently got a Kendrick strip for my SCT and the dew-not strips for my refractor and 2" eyepieces. While I haven't used them much lately due to the weather to know which is best, I do remember some claiming for the Dew-not strips that since there isn't as much insulation between the heating element and the OTA, that they will be more efficient at heating, saving a bit more juice for the battery.
I can at least confirm that the back of each strip is different, so this sounds plausible.

Looks like the current draw is similar between the Kendrick and Dew-not for the 2" eyepiece strip (0.3A vs. 0.35A).

Maybe others will chime in.

Gabe

#8 zippeee

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Posted 27 January 2013 - 02:22 AM

The only Kendrick heaters that seem to have any more material on them are my objective ones. They've got a kind of rubbery/grippy fabric to help keep them in place. Even still, it's really very thin. As for the others, there's just the thinnest layer of nylon covering the heating element. I couldn't imagine it being any thinner.

#9 Daniel Guzas

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Posted 27 January 2013 - 11:16 AM

I pulled the trigger for the Kendrick's binoviewer dew heaters, the premium ones direct from Kendrick themselves. I will post my findings once I receive them.

I am glad Fred1 educated me to the cold weather flexible cables. I think that was what sold me.

I know all to well what -2degF can and will do to plastic at the end of the night of COLD observing. I always fear breaking a line or connection because of the stiffness.

I should have them in a couple of weeks. Hopefully sooner!

#10 Fred1

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Posted 27 January 2013 - 01:25 PM

You're welcome, Daniel. We're all here to share our trials and tribulations. :salute:

#11 csrlice12

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Posted 27 January 2013 - 02:10 PM

Best one I've found is a leather chair, nice fire in the firplace, a nice drink.....as I set there and clean/look at the eyepieces....(due to weather, can't look through them).

#12 zippeee

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Posted 27 January 2013 - 02:46 PM

A picture is worth a thousand words;

Posted Image

The weakest link might be the interface between the conductors and the element. HOWEVER, looking at it carefully I see that the wire insulation is imbedded a good half inch into the rubber and NOT the typical weak solder point we see so often on electrical things. I've been using this one for two solid years and it's still in pretty mint shape (apart from the fact that I took it apart).

#13 Daniel Guzas

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Posted 29 January 2013 - 12:05 AM

Zippee

Thanks for the photo! I am very much looking forward to getting the heaters so I can have my eyes close to the eyepieces while in the cold.

Now it's a balance of trying to get the full FOV while not getting greedy and fogging the heck out of the eyepieces. Hopefully after I get the heaters I will have all the time I need at the eyepiece without fear..

Thanks again all!






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