Hmm ..
This looks interesting and promising ..
The dish doesnt return exactly where I want it to ..but the errors seem less pronounced ...
Pole top wobble ..
ie the clamp ..therefore the motor ...therefore the dish listing to left or right either side of TDC ..
not a visible quantity to the naked eye ..but there is space to insert a couple of thin penny washers at the front of the top lip of the clamp ..
I popped a couple in at TDC ...and the return from E or W is closer to correct ..
ie ..stopped the wobble ??
Looks like the top clamp lip is not exactly a right angle ??