Posted 29 July 2014 - 08:06 PM
Posted 30 July 2014 - 12:40 AM
Posted 30 July 2014 - 04:53 AM
I live in northern MN where the winter temps 0 and below. My observatory is a skyshed pod with a LX200. I want to view in the winter. I can stay warm but what about the scope(tube and electronics)? I don't see anyway to heat the skyshed. Any feedback would be helpful.
You really want the scope and observatory to be the same temperature as the surrounding environment. Otherwise thermal currents will ruin your seeing.
Posted 30 July 2014 - 08:13 AM
Posted 30 July 2014 - 09:07 AM
Mechanicals and electronics are another story. Greases thicken at low temps and the slew rates should be set accordingly. Most consumer electronics are only rated to work down to 32F. I've had USB hubs misbehave at 15F, and a camera power cord that cracked at -5F. Computers generally heat themselves to a reasonable internal temperature, but any fans inside will quickly announce if the bearings are up to snuff for cold weather use.
Batteries have only about half their normal power capacity at low temperatures. Lithium cells are much better in this regard.
Posted 30 July 2014 - 04:45 PM
There are really 2 issues. The first is when you are not observing/imaging while the second is when you are.
In weather this cold the temperature can swing easily and my equipment was often covered in dew/frost. Also, the area between the dome and walls has a nice space for air circulation. However, in winter this can let in snow so I block it with 1" foam strips. To keep the equipment dry I run a small heater/fan. The slight heat and moving air keeps things dry. I use this one http://tinyurl.com/l3co4aw
When imaging/observing I do not have any heat on as that would cause air currents. As stated above the equipment warms itself until the temperatures I mentioned - then I have problems, so I head inside.
P.S. - don't forget to lubricate the lock as it can freeze easily in winter.
Posted 01 August 2014 - 08:29 AM
Posted 01 August 2014 - 08:30 AM
I use Gerbrings stuff...just a heated jacket LINER which I wear over a plain t-shirt BUT under an extra large sweat shirt ...a pair of heated GLOVE liners (one size smaller then normal) that I wear under a pair of finger-less mittens and a pair of heated socks ...I also use a thermostar that allows me to heat all 3 items to the temperature I want individually...
Glove liners have heating element on the top of the hand as well as between each finger The socks I use have heating elements on top of the foot as well as the bottom of the feet... I wear them over a regular pair of socks and a pair of bedroom slippers...
Seriously I am very comfortable down well below freezing..although I seldom go out on the rare nights here that the temp drops to zero...
Posted 01 August 2014 - 09:05 AM
I leave my scope uncovered and place the West Marine fan on a small table to let it blow over the scope. It actually creates enough air movement to keep the Pod above the dew point. Its made to run all the time and I always have it on during the winter unless I'm observing/imaging. It seems to create almost no heat and hardly turns - this is ok. It only draws about 75 watts even though it says it draws 90 watts on the box. I talked to the engineer and the 75 watts is correct. I always worry about covering my scope as the cover can hold the moisture in and not let the air from the fan blow over it.
I assume any lock lubricant will work - even just WD40. Also, lock de-icer should work. After mine froze up the first winter, I've always kept lock de-icer on hand - just in case.
Also, I started to close the Pod so that the lower dome - the part that slides under - is facing south. This allows the sun to shine on it keeping the ice off and allowing it to slide easily under the upper dome.
I'm not sure where you are located but we have had cold and rainy weather this July and we are hoping for a better August. All this planning for winter is great but I'm still waiting for a proper summer.
Posted 01 August 2014 - 02:03 PM
The only issue I've heard is that many cameras can't handle having a temperature less than ambient... so if it's -35C, you're going to have a hard time controlling cooling. Essentially unregulated.
Posted 01 August 2014 - 07:21 PM