Focus coil does not have sufficient range

[LukeSimon]

Yeah, Magnavox T933, but to a lesser extent also my Magnavox T931 has similar symptoms but not as extreme. The T931 reaches optimal focus just before maxing the focus control whereas the T933 is still far from ideal focus when at max. R150 is part of a voltage divider that is inbetween the focus coil, which is an adjustable buck boost transformer and the kinescope focus anode, and so I had suspicions it was a problem. I will test it to see. I will also try swapping in a new focus tube, HV rectifier, and HOT.

Side thought: if the chassis is going to use a voltage divider on the focus rail, why even bother with the buck boost transformer? Why not just use a 50meg pot as the focus control?