The idea's not a bad one but I've yet to see it actually done (on an SCT) to anyone's scope around here? For starters, how would you "enclose it round the base of a cat cooler"? You seen one of these in the flesh Dave? Also, where would you place the internal sensor? I'm not in a blinding rush to pull my SCT apart. Not to mention the actual construction itself. I'm not trained or experienced in any way in anything electrical or technical. I can, however, write you a pretty good feature magazine article or read a news bulletin! What's simple and straight-forward to you is a little daunting to some of us Dave.
I haven't used desiccant in my scope very often but there doesn't appear to be any residue from outgassing. I use the small packs from inside pill containers and place them inside the film canister. The bags used in these packs appear to be very dense and tough - maybe thats enough to filter any outgassed material?
-Tony
I can't get hold of these peltier coolers in my area! I'm out in the sticks here. No problem for me building a system. The sensor will go on the end of the pipe on the cooler Matt. When the coolers inserted, instant internal temp readouts.
ok, asi or mick pinner with his skills would have to make it, but it you get asi homemade tube for blowing air up the tube and into the cavity of the c9.25.
instead of drawing air from the surrounding air, you attach the peltier / heat sink to where the fan is and enclose it so that only cold air from the cold plate is sucked up the tube.
Great topic chaps, The peltier will only dryout and cool a small amount of air; so the question should be what sized peltier is needed to cool and dryout the required air flow from the fan used.
Sorry I don't know the answer; but perhaps someone at www.techbuy.com.au can help. Good luck
It sounds like us SCTers need a little box like an esky that we can put our scopes in and cool them in there. That way we would have greater control of the temperature and humidity. Once the scope reaches ambient we can then mount them. Bit hard for those with fork mounts though.
Believe it or not Paul, I think you've come up with something there!!!
A couple of years ago, I made this esky at work (out of sheet metal)....I reckon it will hold the SCT OTA no worries! Yes! OTA in sealed esky....controlled air from hypothetical source ducted into esky! I'm going to dig it out of the shed & post a pic of this esky I'm talking about......
Yeah and minature airconditioned cool box. It will be important to match the internal with the external temp fall. One of my concerns would be that when the OTA is removed from the box it will becoming from a low humidity environment and moisture in the air will instantly start to condense on the OTA. There needs to be someway to prevent the external air from getting into the OTA. Condensation on the outside of the corrector plate isn't a prob, getting it on the inside would be a different story. Maybe that dust/humidity filter would work in that situation.
Few things to think about to solve this little problem
Here it is. Inside dimensions: 1000mm L 500 W 450 D. Big enough to hold 2.5 possibly 3 slabs of beer Made 2 boxes, one 3.5" smaller than the other in all dimensions. Glued that white packing foam (1.75" thick) on all surfaces of the smaller box, Slipped the bigger one over the top. Even just to keep the OTA in it & leave it in a cool room all the time would have to help. I'd rather see it kept at ambient though somehow.
A normal bought esky would do just as well. Why not just cut a hole in the esky & mount a fan & peltier system to that? Have the scope sealed, naturally. If you could preset the temp to whatever you wanted, roughly to what your ambient gets down to normally in your area (here its about 6-8C this time of year) You could have it running 24/7 if you wanted to at home.
Interesting. The finder I put in the fridge I put in a ziplock bag. I took it out after nearly 2 hours in there. It immediately fogged up after taking it out of the bag in the house as you'd expect. But when I took it outside seconds later the fog burnt off the optics within seconds. I can guarantee its not as cold outside as it is in my fridge.
You need to get hold of a couple of hygrometer to make a comparative measurement of relative humidity inside and outside. By the sounds of it, much more humid in the house than out, which at that time of night sounds pretty normal.
![[1ponders]'s Avatar](../vbiis/customavatars/avatar45_9.gif){kind=avatar}
Made 2 boxes, one 3.5" smaller than the other in all dimensions. Glued that white packing foam (1.75" thick) on all surfaces of the smaller box, Slipped the bigger one over the top. Even just to keep the OTA in it & leave it in a cool room all the time would have to help. I'd rather see it kept at ambient though somehow. 
