Hello Al, You said ...

I already have the equations for LO19 in front of me... simple ennuf for a five year old!

Aye, well, then you can appreciate the work LA2QAA had doing is' sums "longhand".

Remember, my last remaining active dozen or so braincells have been 'out to lunch' for the past 5 years.

73 John. la2qaa@amsat.org