NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Bubble sextants on eBay
From: LJ Dram
Date: 2007 Jan 07, 04:49 -0000
From: LJ Dram
Date: 2007 Jan 07, 04:49 -0000
I bought a Kollsman periscopic sextant from a surplus dealer about a month ago, and have found the lamps and averager work OK with ~27 VDC from three 9-volt batteries in series. Mine was about $65 from Surplus Shed at http://www.surplusshed.com. Their current stock seems to be fairly recent surplus -- my sextant arrived with a military service tag in the case indicating it was removed from service in 1998 (from a C-130H aircraft) because the silica gel in the dessicant chamber was saturated. It has the electronic averager, not the older clockwork mechanism. The sextant is in good working condition and came in its original fiberglass carrying case with several spare light bulbs, a Y-cable for the 28-volt power supply, and miscellaneous 8-year-old military paperwork. After some difficulty figuring out how to form a bubble and adjust its size, I've had little trouble using the sextant. I agree with earlier comments about the bubble illumination system, and found no problem taking sights of Polaris and Diphda (mag 2.06) from my back yard. Hand-holding the Kollsman sextant is not all that easy, since it has no handles or grips, weighs about 7.5 pounds, and the 10-inch tall periscope assembly makes it a bit top-heavy. It helps a lot if you can brace it against something solid. The electronic averager is a masterpiece of 70s-era technology, with what looks like a miniature Nixie tube for the seconds display and several LEDs that light up to indicate if you have the altitude set above, below, or right about at the average value for the sight. In my experience, altitude can be read to within about +/- one minute when using the averager. Cheers, ljd --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---