clear tonight

[MarkS]

Mark does 0.3 really make all that difference...? (whatever 0.3 is...)

The SQM measures in visual magnitudes per square arcsecond of sky.  A difference of 0.3 means the sky is approx. 35% brighter.  This is quite noticeable visually and adds more background noise to an image.

At 4am when I was imaging the comet the sky was back to its usual 20.9

I had technical problems last night also.  The camera froze (i.e. simply stopped working) twice and EQMOD lost connectivity once.  Probably a USB issue caused by my failing 12volt battery.  I need a new leisure battery.  Can anyone suggest where I might find info on leisure batteries

Mark

[The Thing]

Batteries, mine went to the recycling before Christmas. Whenever I've had camera or mount problems it's usually power.

In my observatory I'm now using old laptop power supplies and ebay buck converters with voltage readout to get the right output (just seen they are half the price I paid now!). They are more reliable than the PC power supply I was using. Loads of good power with reasonable protection for gadgets and resistant to moisture, they are well sealed and tough. I've used bungies to hold them against the pier (which is bubble wrapped against dew forming on it). I've modded the mount to use an aircraft style screw locking connector for the 12v feed.

[JohnP]

A difference of 0.3 means the sky is approx. 35% brighter

Blimey - I didn't realize it was that much...

[Fay]

No I did not realise either!

[Carole]

I need a new leisure battery.

Why are you using batteries Mark?  Now you have an obsy you can use mains, and when we are at camp we have hook up.

Carole

[RobertM]

Like Duncan I use laptop PSUs but run mine through a Cyberpower UPS which has been hacked with a 115Ah leisure battery; that should allow an imaging session to finish even with a power cut.  I like the idea of using those Buck boost units close to the equipment, they provide a bit of isolation and make sure it really is 12v at the equipment.

Carole: yes I can close the roof manually.

Mark, I got my latest leisure battery from halfords (good price in the sale).

Robert