NavList:

1)A question please for lunar/Bygrave/nav triangle experts. Possibly Gary LaPook, Ronald van Riet, John Karl, Frank Reed?(Happy posting 10th birthday Frank!)
I realise the 1' accuracy of the Bygrave is probably not good enough for regular lunars, but, I'm getting very accurate results so far using John Karl method page 93,if I start with known Relative Bearing angle(RBA), declination (ho moon),lat (Ho sun).I basically do the "great circle" calc and get accurate LDo. (much quicker and less moves than the Fuller using sine/cosines.) However, I have to start with known RBA. Question, how do I do the first calculation, ie find unknown RBA with known Hsd,hsd, LDsd, dec and colat? I cannot get my head around the maths using cosines and cotangs for the Bygrave.I can do it on the Fuller using John's cosine/sine formula, but it is pretty laborious. As an intellectual challenge, could anyone help me work out a method to calculate RBA on the Bygrave?
2)There was a lot of discussion on Bygrave replica manufacture over the last few years. Any updates on status from anyone? I have an original MK11A circa late 1920s, but no serial number and a homemade replica, both work perfectly, if anyone interested in details.
Best wishes, Francis.
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