HP 70427A User Manual page 264

0.05 PM/V
This softkey sets the reference chain's tuning sensitivity to
0.25 parts-per-million (0.05 PM/volt). The 10 MHz reference can be tuned
externally from the front-panel TUNE VOLTAGE connector. The
100 MHz oscillator is locked to the 10 MHz reference and the 600 MHz
oscillator is locked to the 100 MHz oscillator.
Select this sensitivity for applications requiring the lowest possible noise at
offsets offset ≤ 100 Hz.
If the module is being used with the HP 3048 Phase Noise Measurement
System with this tuning sensitivity, the 100 MHz PLL bandwidth must be set
wider than the HP 3048's loop bandwidth.
Path
HP-IB command
Figure 10-20 Reference Chain
Ref Chain Tune Sense
REF:TS 1
HP 70427A/HP 70428A User's Guide 10-21
Softkeys and Displays
0.05 PM/V
0.05 PM/V