Dew heaters and built-in dew shields

[RichieJarvis]

Hi All,

I've got a 2 channel dew heater coming. It occurs to me how you make one work with something like the Williams Optics and Astro Professional sliding dew sheilds?

I always thought the bands had to be over the lens cell?

I must admit, I've never used a dew heater before, so any advice welcome!

Cheers,

Richie

[FLO]

For a William Optics telescope, extend the dewshield then wrap the dew heater tape around the OTA behind the shield and slide it as far forward as it'll go until it bumps up against the shield. This way it'll be just behind the optic and will work fine.

HTH

[RichieJarvis]

Thanks steveo!

[blinky]

Thats what I did at Kielder and it worked a treat!

[FLO]

I don't know why but dew heater tapes do seem to work well, perhaps better, when placed just behind the optic, particularly with SCTs.

[Psychobilly]

possibly beacuse if the band is behing the "optics" the heat is "trapped" inside the OTA rather than radiating off into space if its level with or slightly infront of it...?

Just a thought....

Billy...

[Kai]

I always place mine behind the lense.

[stefski]

Good to know about the 'behind the lens' thing ....I'm yet to try out my new dew heater 'a la Blinky' on my SCT.

Stef

[Albireo380]

The dew heater tape sits about an inch behind the corrector plate on my 8" LX90. This is because the dew shield needs 2" of OTA to "grip" properly. I was a bit concerned that the "rear placement" pf the dew heater tape would reduce its effectiveness, but I have found it works just fine.

Tom

[RichieJarvis]

Mine will be a 'blinky' as well once I get it...

Thanks for the info though - thats perfect!

Cheers,

Richie

[FLO]

Mine will be a 'blinky'

That'd be a fantastic brand name

[steviejasp]

Not meaning to hijack the thread but...............

If i knew then what i know now.

I bought a combined shield/heater for my lx200. It works beautifully and i havent even seen a drop of condensation on the front element. The trouble is i would like some kind of counterbalance system to offset my dslr but it seems they all need to be mounted to the ota using the screws around the front and back of the scope and you cant cut the shield away at these points as it would mean cutting through the element .

Any one come across this too?

[FLO]

Steve, some of the larger Flexiheat dew shields are notched for situations like this. I'll make some inquiries and get back to you Mon/Tue. Is your LX200 the gps version?

[steviejasp]

Hi Steve, it is one of your Astrozap ones for a 10" LX200R