NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2019 Feb 14, 11:54 -0800
Bill some non equilateral sextant sights for you. I observed them today on the Sun after doing ten calibration sights on each stud setting using Franks GPS Antspoof App and finding an average instrument error. I've purposely not put my observation position on, but it's not far from 53N 000.30W. I rather like using the basic Hughes MkIX. It's much lighter and much better balanced than the clockwork ones. This one was overhauled by Paul Brewer and it works a treat. We don't try to fiddle too much with the calibration. We just accept what we get. It's in one of the original aluminium cases, before they stole all the alminium to build Spitfires. I used 'Navigator' to find GHA and Dec Sun being too lazy to do all that time to arc stuff. We didn't need that on Vulcan's; with five people helping, we always managed to centre about an Air Almanac ten minute time. I'm taking a bit of a risk sending this without tripple checking it, but it's a clear night, and I thought I'd go out and find somewhere with no light polution and get some star sights before the mist comes in.
Sextant: H. Hughes & Son Bubble Sextant MkIX Serial No 230/40
Calibration: 10d stop add 6’, 10d +5d stop add 6.5’, 20d stop add 6.9’
Date:
Body: Sun, Centre, Bubble Horizon
Time: 10.03.07 GMT Hs 17d 50.6’
Inst corn +6.0’
Refraction -3.0’
Ho 17d 53.6’
GHA Sun 327.14.1 From ‘Navigator’
Assumed Longitude 000.14.1W
LHA Sun 327 Dec 13d02.8S From ‘Navigator’
Az: 146 Hc: 18d11’ d-56 From AP3270 Vol 3
d Corr’n -2’
18d09’
Intercept: 15.4’Away
Time: 13.05.55 GMT Hs 22d 53.8’
Inst corn +6.9’
Refraction -2.0’
Ho 22d 58.7’
GHA Sun 012.56.1 From ‘Navigator’
Assumed Longitude 000.56.1W
LHA Sun 012 Dec 13d00.3S From ‘Navigator’
Az: 193 Hc: 23d12’ d-59 From AP3270 Vol 3
d Corr’n -0’
23d12’
Intercept: 13.3’Away
Time: 16.04.51 GMT Hs 07d52.6 ’
Inst corn +6.5’
Refraction -7.0’
Ho 17d 52.1’
GHA Sun 057.40.2 From ‘Navigator’
Assumed Longitude 000.40.2W
LHA Sun 057 Dec 12d57.7’ From ‘Navigator’
Az: 236 Hc: 08d54’ d-52 From AP3270 Vol 3
d Corr’n -50’
18d04’
Intercept: 11.9’Away