Heated dew strip or heated dew shield for sct

[Bender]

My 8" sct is fairly new to me and I had to pack up after a hour as the scope started to dew up despite the dew shield.

So a dew heater is becoming more alluring. Just wondering if a simple dew strip is doing the job on 8-11" sct's or if a heated dew shield would be a better option.

Them I think I would also need a dew controller and power tank to get it working.

[baggywrinkle]

When I bought my 9.25 SCT I did order a combined shield and heater but the deliveries were really long, so I had to go with separate shield and heater.

I used it last night and it was heavy dew fall in the Fens. It worked a treat....now got to get a heater for the RACI!

Yes I run it off a power tank.

[ollypenrice]

You only need to heat the rim of the tube around the corrector so a strip is fine, but you also really want a dewsheild. That means a dew shield that will fit with the strip in place. Making your own from camping mat might be best.

Olly

[Bender]

Thanks Oly, so a dew shield with build in heater strip ticks all boxes?

I read somewhere that from 8" on you wouldn't need the dew controller as you need max power anyway. Is that true?

[YKSE]

Agree with above mentioned.

I had only dewshield before for my C8, when humidity was over 80%, it would dew up in a couple of hours. Then I added heated dew stripe around the corrector plate, it keeps dew-free even in 100% humidity, even if the OTA is soaked.

I have controller to the heater, it's on mid-power all the time.

[rob0971]

I have a heated shield for my C9.25. I also have a controller that I start off on full power then drop to about half way after half an hour. Never had a problem with dew while using it, dews up really fast without it.

[Owmuchonomy]

The only way to keep the freshest Yorkshire dew off my 9.25" is a Kendrick dew band and a plain dew shield. Note that the precipitation of dew is a function of the dew point not just the humidity. The new Clear Outside website from FLO publishes this information in its weather forecast.

[Tinker1947]

When i had the C11 i used a Astrozap dew shield with heater combined, on the out side i put another dew strip, the corrector never dewed up, i never tested it with only one heater on.....

[Permafrost]

Hi Guys, I've been thinking of a similar setup the past few days and found this topic..

I have an Celestron 8" Edge HD SCT, and want to buy a Dew Not Heated Strip http://agenaastro.com/dew-not-dew-remover.html and attach it to the top of the OTA on the corrector lens and than also add an Astrozap Dew Shield.

These are the strip's specs:

Model, Length in In, mm, Watts, Voltage, Amperage

DN009   30.0"  (762mm)   14.0   12v   1.18

I'd like to know 2 things:

1) Can I get by without wasting 100$ on a controller and just leave it to the maximum setting? (I just want to heat the OTA)

2) And also, which battery to buy? Is there not a battery that can shoot out half the amperage? If not, which inexpensive battery can I buy?

Thanks!