Link A-12 Aircraft Bubble Sextant (WWII)

Link A-12 Aircraft Bubble Sextant (WWII) !*OBO*! !*OBO*! This is a Link A-12 bubble sextant with its orginal carrying case. THIS IS ANTIQUE FROM WWII ERA!  They are collectable but can be still used today . They are meant for practical use either in the air or on land.  Bubble sextants normally cannot be used at sea. These instruments are sold with one bubble chamber only, which is why I have reduced the price from $500. Most navigator's never bothered using the second bubble, and for reasons explained below you will most likely never want or need to swap out the bubble chambers. Forget any war stories you may have heard about the A-12. These were originally used during WWII as training instruments for navigators.  They were not used on combat missions because there was no accurate way to mount or to aim them in a bomber or fighter.  This is made evident by the standard tripod threaded hole in the side of the instrument.  However, for precisely this reason, it is the best possible terrestrial sighting instrument available, save perhaps for a theodolite. With the celestial sights with the A-12 model its Relative to its ease of handling and sighting, in many ways, this is the most precise bubble sextant that you will find anywhere. It is consistently accurate to below three minutes of arc when properly worked and read.  Not even a $1800 Cassens and Plath can compare when used with its $950 bubble attachment. What's more, this sextant has the widest field of view of any marine or aircraft sextant I have used and because of its ergonomics and relative lightness, it lends itself well to backyard navigating. If you look up this item on the aircraft sextant listings of Celestaire, you will see that a properly reconditioned A-12 normally sells for about $700. However, these bubble chambers have been sealed and tested to the extremes of temperatures.  The instrument comes with a bubble chamber servicing kit so that you can modify the size of...