NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2014 Oct 2, 12:49 -0700
Marty,
Try USNO as a check also. Determine your Ho and compare to USNO Hc for your intercept. Adjust shading for equal brightness of Sun images. There is nothing wrong with superimposing the images which is how I like to do it when using a x2 scope. I seem to get the smallest intercepts around LAN when the altitude is changing slowly. Don't expect perfection especially when it is windy. For timing try starting the stopwatch on the minute using short wave signals at 5, 10, 15, or 20 KHz. then take splits for each observation that are added to the start time to get UT time of observation. If you don't have a short wave then use GPS time or the attached online link to UTC.
http://aa.usno.navy.mil/data/docs/celnavtable.php
If 3' intercepts persist then post your complete observation information and reduction.
Greg Rudzinski