[raymo]

I am not very comp literate. I bought BYEOS and have never used it.
All I have measured fairly accurately is my possible sub time without
star elongation. With a f/l of 1000mm at or near 0 declination I have always managed 60-90 secs [depending on my P.A.], and at high
decs such as Crux, 100-120 secs. In both cases the limiting factor
was drift in Dec, not in R.A. Now I get around 9-10secs and 16-18 secs
respectively. During that short space of time there is no Dec drift at all; all of the drift is in R.A. so it is tracking much slower than normal. I have checked everything mechanical, no slipping gears.
As I said in another thread, adding or removing large amounts of weight [7-8kg, not good for the motor I know] made no difference to the tracking rate, so I think the problem is electrical rather than mechanical.
raymo