Hi Chris
I will try and explain it to you,
, remember this is Tak......
There are 3 different Extenders/Focal Reducers and Flatteners.
The CAA is the same for all the 2.7" focusers.
For the FS-102/128 you use the Focal Reducer/Flattener, it is 2.7" in Dia and screws onto the CAA, a CA-35 is then screwed to the rear of the Focal Reducer/Flattener, screwed to the rear of the CA-35 is a Wide T-Mount (A special Tak camera mount), attached to the Wide T-Mount is your camera adapter.
The 1.6x Extender just slips into the 2" focuser and brings the scope up to about f/12 or so BUT you need the CA-35 (50.8) to give you the right distance back for your camera's focal plane.
Please note: The CA-35 and the CA-35 (50.8) are two different bits of equipment.
The 35 Flattener is different again, as I said earlier, it was designed for use with the TOA and TSA series which are triplets, not the FS series which are doublets. On the TSA-102 it reduces the focal length from 816mm to 800mm, the FS-102 has a f/l of 820mm. When you use a 35 Flattener in an FS series, I believe that there is not enough Infocus. With the TSA-102 you have to remove the CAA to get enough infocus. The 35 Flattener slides into the 2" focuser and the CA-35 (50.8) slides into it to give the right distance back for your camera.
All very confusing so I hope I have explained it properly
Cheers
John G