A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2019 Mar 30, 13:45 -0700
Russell Crum you wrote:
I am a former navigator (canadian) trained on Kollsman sextant. Flew ASW during the 70's in CP147 Argus. I have a kollsman sextant but no mount, and cannot find one. I'd be grateful if you could shed any light on where i might find one.
The first thing is to check on the left hand side if your Kollsman is 28V or 3V. If put together in North America, it’s almost certainly 28V, but I seem to remember that the Argus was a very much modified Bristol Britannia derivative, so if your Kollsman came from an Argus there’s a tiny possibility it’s 3V.
Mountings are much harder to find than sextants, presumably because they didn’t need to make as many, and many are still in the aircraft or were scrapped with the aircraft. They might also be in cupboards in museums, because they were removed when the aircraft, kept in the open, eventually started to leak. If you’re planning to power the sextant directly, the voltage of the mounting doesn’t really matter, because they’ve both got the same size hole. There are also even rarer, more simple, unpowered mountings. These too have the same hole size. I got my Kollsman mounting by putting a 'watch for' marker on eBay, and eventually one came up. Expect to pay slightly more than you’d pay for a sextant, perhaps $100 vs $70. Don’t be tempted to pay the price asked by ’Buy it now’ dreamers. Make an offer instead.
In the meantime try, sitting your Kollsman on fine wedges of wood or a bean bag on a window ledge facing the body you wish to observe. Power the sextant lighting with three 9V PP3 or two 1.5V AA batteries taped together, but be careful you’re not losing power into any heater circuit or the batteries won’t last five minutes. I have a feeling you can observe the Sun with a bubble Kollsman without any power at all, but I might be wrong. I couldn't check just now; my bubble seems to have temporarily gone walkies.
Then just open the window and kneel in front of it. You have to be happy with the star of course, because you’ve no azimuth setting. If there’s a radiator on the wall, it’s lovely. DaveP