Celestron dew heater ring


Howard Ritter
 

Has anyone tried using a Celestron dew ring on an A-P 155 refractor?

Celestron offers a line of dew heater rings that mount to the front of the corrector-plate cell of its SCTs and RASAs. I have one for my RASA 8. It’s a very elegant device that replaces the front ring of the corrector cell. The heater is metal and the heat is applied directly to the periphery of the corrector without having to diffuse through a fabric sheath and a highly conductive aluminum tube.

In looking for a dew strap for my 155EDF, I noticed that Celestron’s line includes a 152mm model. The catalog doesn’t give the OD or ID, but I’m going to ask them. If this would fit flush against the lens cell, it might be the ideal solution, and I could use it with the Celestron dew-heater controller I already have.

I’m certainly willing to risk return shipping if I order one and it won’t work, but if someone’s already found that it doesn’t (or does), that would be helpful.

Any technical issues or cautions?


Thanks,
—howard


ROBERT WYNNE
 

If less than a 1/8th inch gap .118" vs .125"- affects the rings form, fit or function - which I don't believe it does - then you should be OK. The slight 1/8th inch gap would only be a visual distraction. Alternately you might be able to fill the gap with a similar thermally conductive material.

If the function of the ring relies on its ability to completely mate then functionality is compromised and the ring won't work. I find that hard to believe. It may not heat at 100% of its rating or the heater stays on longer than it otherwise might.

But I see no big mismatch in specs. that would cause the ring not to work as advertised.

Best,
Robert

On 09/24/2022 6:02 AM Howard Ritter via groups.io <howard.ritter@...> wrote:


Has anyone tried using a Celestron dew ring on an A-P 155 refractor?

Celestron offers a line of dew heater rings that mount to the front of the corrector-plate cell of its SCTs and RASAs. I have one for my RASA 8. It’s a very elegant device that replaces the front ring of the corrector cell. The heater is metal and the heat is applied directly to the periphery of the corrector without having to diffuse through a fabric sheath and a highly conductive aluminum tube.

In looking for a dew strap for my 155EDF, I noticed that Celestron’s line includes a 152mm model. The catalog doesn’t give the OD or ID, but I’m going to ask them. If this would fit flush against the lens cell, it might be the ideal solution, and I could use it with the Celestron dew-heater controller I already have.

I’m certainly willing to risk return shipping if I order one and it won’t work, but if someone’s already found that it doesn’t (or does), that would be helpful.

Any technical issues or cautions?


Thanks,
—howard





Yuxuan Wang
 

The biggest issue is that your beloved AP scope will become a Celestron.


Howard Ritter
 



On Sep 24, 2022, at 16:34, Yuxuan Wang <coolwangyx@...> wrote:

The biggest issue is that your beloved AP scope will become a Celestron.
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