A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: David Pike
Date: 2016 Dec 23, 03:10 -0800
Please will someone confirm a few facts about my ex-Bundswehr Kollsman pendulous reference periscopic sextant A28450-00-002 serial 20026 and its ex RAF Nimrod mounting?
1. What is the purpose of the small spring loaded to centre lever on the left hand side (arrowed in the photo)? As far as I can see pressing it ‘down’ temporarily removes the constraint which normally prevents you from seeing through the sextant when it isn’t wound up. Pressing it ‘up’ seems to fulfil no useful purpose.
2. Why does the calibration card have two values for each height sextant? My guess is that one set of values is for approaching the angle from below and the other set for approaching it from above to give an idea of the slack in the system.
3. Do all Kollsmans hang right side down in their mountings because of unequal mass distribution? Has anyone experimented by loading the left-hand side with lead or using stiffer grease in the mounting?
4. If apply power to the mounting, should the azimuth counters window light up; the sextant itself is lit from a modified ‘Ever Ready’ 3V torch?