[ Update Dec. 2000: My 2010 seems to like Vref in the 1.85 - 1.87 volt range. ]
Background: VT1 adjusts SSB reference voltage, VT2 adjusts SYNC reference voltage. These go to IC-10 pins 4,2, and are switched out on pins 1=3. IC-10 pins 1=3 are connected to a 6-pin connector at bottom edge of shield. You can get a probe on pin 6 to measure the voltages without removing shield. See service manual component layout.
I'm so glad I measured these before I started! SSB= 1.85, Sync= 1.81 volts. Radio set at xxxx.0 for adjustment. Note: Sync changes with tuning, so make sure you are on xxxx.0 when you measure.
Following the procedure in the Sony service manual, I set SSB for 1.5 volts, tweaked the cap, and adjusted sync. Result was that sync-lock-center was way off. Most of the lock range was on USB. Repeating the procedure using SSB=1.6v, lock center was still off. Using SSB=1.7v produced OK lock center, but SYNC voltage was high by comparison. Using SSB=1.8v, and repeating the procedure yet again produced matching SSB/SYNC reference voltages. Gee, you think maybe Sony knew that when they aligned it?
Unless my unit is unusual, it looks like the service manual is off.
Larry Russell .... in Flushing, Michigan