A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Gary LaPook
Date: 2016 Jan 19, 21:27 -0800
But not all of them, see attached manual page. Some used 3 volts supplied from a flashlight size battery case. There are bulbs that fit the socket in 3v, 6v, 12v, and 24 volt ratings so you can make up a battery pack that you want and then just put in the proper bulb. Three "AA" put out 4.5 v and work well with a 6v bulb and is very compact, I velcroed such a power supply to the back of my MA-2. If you want 28 volts then three 9volt batteries in series will get you there. If yours has the electronic averager which uses a lot of power then this doesn't work too well since the averager eats batteries, better to use a 24 volt tranformer available at Home Depot or Lowe's for your sprinkler system, very inexpensive. I also posted how to make a 28 volt source powered from a 12 volt car socket, costs about $30 and is simple to make. I have posted a lot of information on this in the past so just research the archive.
The Kolsmann bulbs are 28V, but fairly readily obtainable. You may still need the bubble light during daylight to get a good balance between the target and the bubble. You could use any handy 24v dc or ac power supply to run it. The 9v batteries wont last any time.