Well I did a bit of experimenting tonight and it didn't matter which adapter I used I didn't get the problem I was having the other night. I did work out which direction the drift was though, RA+. Then it dawned on me, clutch slippage.
I had the scope pointed directly east at about 25 deg with a whoppin' great SBIG and filter wheel at the end of a 100mm f10 refractor on a poor little EQ4 mount.
Another bonus of the nights exercise I now have the periodic error measured so I can play around with that now. I think it's time to do the Astroboy CG5 turbocharge to this little mount
The two images below are from each of the adapters. The PE looks pretty constant, though horrendously large
. I'd be interested to find out what is making it gradually climb though.
Ignore the pink Dec graphs, I hadn't polar aligned accurately to start with and then with the second one I had only adjusted to altitude and as the mount pointed higher the azimuth drift error started to creep in. Mind you if you look at the second graph carefully and read the .csv file generated you will see that up until around 1100 sec there was less than 3 arcsec drift in Dec (approx 0.15 arcsec/min). Ya gotta love K3CCDTools for drift aligning
