My manual shows a different socket PCB. On mine the
wire goes to one of....
F0 ground
F1 275 V
F2 500V
F3 870V
The other end of the wire to move goes to a 560 K ohm resistor.
I think the white wire is just a jumper & not to be moved.
Usually moving focus jumpers make little or no difference in
the picture.
BTW the set in my manual looks very different ( newer ) than
yours.
73 Zeno
