had the same trouble b4, and set em up with the stobe so the were nigh on perfect @ the various dot sizes.

or this is the official way,

pitch control +- 0% adjustment

connect a frequency counter to points +tp27 -earth point , turn on the power, set the pitch control to zero, adjust pitch pot vr301 so the frequency is 262.08 khz +- 0.05 khz



pitch control gain adjustment

set the pitch to zero, pull out the conector cn102 of drive p.c.b, conect a multimeter to terminals 5 and 6 of conector cn102 on the pitch control p.c.b side, adjust vr302 so that the resistance is 2.7 killer ohms +- 0.1 killer ohms.


the above is from the technics service manual.