Telescope Reviews: How do you keep warm in cold northeastern nights?

Multiple layers, starting with long johns. I often wear a one piece set of Carhardt coveralls, or a heavy army jacket with a hood. I wear work boots with thick boot socks, and sometimes I put a chemical handwarmer in each boot. If there is ice and snow, they need to be water proofed, there's products available with which you can treat your boots. Insulate soles are also a must if it's snowy or icy out there. I cover my head with multiple layers as well, using hats, baclavakas or both under the hood, which also can be used to screen out stray light.

As for your experience with your battery pack blowing up, that is a reason why I install fuses, circuit breakers or both in electrical systems. A dead short was the cause of the battery blowing up, because there was a nearly resistance free path back to ground and that meant a huge amount of current can flow long enough to destroy the equipement. The less resistance in a circuit, the more amperage can flow though it, and that means even a small 12-volt battery can for a short time deliver hundreds of amps with destructive results. Imagine what 480-volt alternating current can do during a short circuit. When dealing with 480-volts, let alone 13,800-volts, a dead short like that will cause a massive explosion, fire, and death for anyone near the equipment. Even a 12-volt battery has a lot of punch, you can actually weld metal with a pair of them wired in series. When arc-welding, a welder is deliberately creating a short circuit that is enough to turn metal into a molten puddle. A fuse will blow or a circuit breaker will trip in the event of a short circuit, saving your equipment. When I was using a homebuilt controller, having that fuse in series with eveything prevented a big problem more than once. A common source of trouble with dew heaters is a short developing at the RCA jack, which can blow up a battery if there is no fuse in between them.

Commerically made dew controllers, or a well designed homemade one will at least have a fuse to prevent this occurance. I recommend the Dewbusters, they not only have short-circuit protection built in, they will let you know if a dew heater is shorting. They will also let you know if the battery is running low. Using one of these controllers will prevent a repeat of the disaster you experienced. They are well made and you can use them with any sort of heater strip, even ones you made yourself without voiding the warranty. You order them from www.dewbuster.com, which also has instructions on how to make your own heater strips for any application. One other thing that helps is keeping your eyepieces in the case, and keeping the lid closed except when taking out or replacing an eyepiece. When it's really dewy, I put a heat pack in the case to keep the contents from cooling down to the dew point.

As for my Dobs, I use heaters on the secondary mirror, eyepiece and finderscopes. On the largest telescope, I also use a shroud and a fan in the mirror box to keep the main optics dew free.

Taras