A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bill Morris
Date: 2019 Jan 25, 13:32 -0800
Paul, you write
<<It should be possible to use an optical rev counter to get an idea of the working speed of the rotor.>
I have just ordered an optical rev counter to do just this. I had no idea they were so cheap! I am pretty sure that the maximum rate will not exceed 1500 rpm and that the rotor will "sleep" at under 1000 rpm.
I have examined both the Russian and German versions of the SOLD bubble sextant and can confirm that they are identical in principle and construction except in minor details. There is a detailed account of the SOLD here:https://sextantbook.com/?s=SOLD