[Elecraft] K2 spot function is off

[Andrew Moore]

I've built and calibrated K2 #4958.  If I use the spot function to tune to the exact frequency of another transceiver, the end result is I'm actually off by about 120 Hz or so.  I've recalibrated a couple times, and my display seems accurate (judging by WWV anyway).  I'm using a 600 Hz sidetone pitch.  After calibrating the displayed frequency, and making adjustments to the trimmer near the 4 MHz osc on the control board, I've done a CAL PLL followed by a CAL FIL (using suggested values from the manual, not using spectrogram...) yet the spot function seems to be off by the same amount every time.

How does one adjust spot?

Thanks,
--Andrew, NV1B