HP 8753E Service Manual page 206

Perform the first five steps of the procedure at least once for familiarization
before trying to select the target spur (especially if you are not using a filter).
1. Connect the equipment shown in Figure 3-10.
Setup for Cavity Oscillator Frequency Correction Constant Routine
During this adjustment routine, you will see several softkeys:
Figure 3-10.
sweeps the current frequency span; you may
press it repeatedly for additional sweeps of the
current frequency span.
sweeps the next frequency span (2 MHz higher).
enters the value of the marker (which you have
placed on the spur) and exits the routine.
exits the routine.
Adjustments and Correction Constants