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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Brown-Nassau graphical slide rule, improved accuracy
From: Francis Upchurch
Date: 2015 Nov 19, 03:34 -0800
From: Francis Upchurch
Date: 2015 Nov 19, 03:34 -0800
My home made full sized BN has generally been accurate to within 5', with occassional outliers of 10' using the recommended techique of placing pencil dots for lat and LHA.
I am now getting average 2' accuracy by only using whole number lat and LHA for AP, using the printed dots and lines which are spaced at 1°
This is as good as the Bygrave, but much faster and easier, with no writing down or calculating intermediates like W, X, Y or co-lat.
Just hope one of you intrepid aviators (Gary or Brian, maybe?) would try it out against the Bygrave.
See attached for details and photos.
Best wishes
Francis
Bygrave fan who now prefers the BN for LOPs!
