HP 8664A Internal Frequency Calibration

[avvidclif]

I have worn out a set of eyeballs trying to figure out how to calibrate the internal reference oscillator on this signal generator. Does anyone have any clues? I have one that is on freq and the other is off 62hz @ 1.5G. I realize that's almost nit picking but the other is less than 5 Hz off.

[avvidclif]

Disregard I found the adjustment hole on the back. Sheesh.

That's what I get for trying to read the manuals instead of looking around.