So I finally gave up and brought a new scope, a Planewave CDK20 with a fused Silca mirror and an IRF 90 Focsuer/Rotator. I put the same old FLI Proline 16803 but it failed with a chip error within a month of operation, a new one is on the way. Below is the scope installed.
It’s installed at iTelescope.Net at Siding Springs, Coonabarabran, NSW, Australia where the 3.9m AAT is. The guys have been unbelievably helpful, not just with the install but with all the new things that can take a little while to sort. There are a thousand thing that happen slightly differently when