A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Joe Wong
Date: 2022 May 10, 23:27 -0700
Just acquired this Kollsman Periscopic sextant from a layman seller on ebay. The seller was unable to perform a thorough inspection on the instrument,so as to check the overall functionality, instead he just stated that all knobs work and the clockwork ticks.
Upon receiving the sextant and examining the sight I dicovered that the bubble is oversized and cannot be adjusted by the "Increase Bubble" knob. Plus there is a quite noticeable "wave-like" distortion located in the upper-left portion of the crosshair (see first attachment).
I intend to restore the equipment back to serviceable conditions but a lack of knowledge and manual guidance prevent me from doing further disassembly in order to work out all the sources of the problems. Although I do suspect that the bubble problem was caused by spirit leak.
I really hope someone here who has knowledge on the Kollsman periscopic sextant, or has real ones in their possession can help me in troubleshooting and fixing the sextant. Much appreciated!!