NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: sextant for use on land
From: Gary LaPook
Date: 2006 Sep 7, 03:46 -0500
From: Gary LaPook
Date: 2006 Sep 7, 03:46 -0500
Gary LaPook wrote:
You do not need 28 volts to illuminate the Kollsman periscopic sextants. All you need are a couple of Caltronics number 328 miniature lamp light bulbs which are the same size as the 28v bulbs originally installed in the sextant but which operate on 6 volts. I made up a 6 volt power pack for mine using 4 AA batteries which I attached to the back of the averager with velcro. You can also use bulbs designed for 12 volts that are Caltronics number 330. You could then make a power cord to use a cigarette lighter socket for power.
I like the A-10 which I bought from Celestaire 30 years ago and I used in flight for navigation across the atlantic.
My favorite, however, is my MA-2 which I bought on ebay several years ago. It has the same body and averager mechanism as the periscopic sextant but doesn't have the periscope tube so is much easier to handle. I like using it in flight because of the averager even though it weighs more than the A-10.
When I got the MA-2 it arrived with a broken pellicle. I did very delicate surgery and removed a good pellicle from one of my periscopic sextants and installed it in the MA-2 where it works fine.
Paul Hirose wrote:
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You do not need 28 volts to illuminate the Kollsman periscopic sextants. All you need are a couple of Caltronics number 328 miniature lamp light bulbs which are the same size as the 28v bulbs originally installed in the sextant but which operate on 6 volts. I made up a 6 volt power pack for mine using 4 AA batteries which I attached to the back of the averager with velcro. You can also use bulbs designed for 12 volts that are Caltronics number 330. You could then make a power cord to use a cigarette lighter socket for power.
I like the A-10 which I bought from Celestaire 30 years ago and I used in flight for navigation across the atlantic.
My favorite, however, is my MA-2 which I bought on ebay several years ago. It has the same body and averager mechanism as the periscopic sextant but doesn't have the periscope tube so is much easier to handle. I like using it in flight because of the averager even though it weighs more than the A-10.
When I got the MA-2 it arrived with a broken pellicle. I did very delicate surgery and removed a good pellicle from one of my periscopic sextants and installed it in the MA-2 where it works fine.
Paul Hirose wrote:
Long after they were first built, some Kollsman periscopic bubble sextants were fitted with electronic averagers. I saw one in the 1990s when I was in the USAF. Every other bubble sextant I know about uses electric power for illumination only. The Kollsman I bought on eBay has the original clockwork averager. An attached sticker says it was repaired in 1994. It needs 28 V to take star shots, since the bubble is invisible at night. All it would take is a few 6 V lantern batteries and some odds and ends from Radio Shack, but I have never gotten around to trying that.
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To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
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