Keysight N9923A FieldFox User Manual page 53

6. Connect the DUT and view the insertion loss measurement results.
When measuring very long lengths of cable, it may be necessary to increase the
sweep time. Learn more about measuring long cable lengths at the FieldFox
Supplemental Online Help:
http://na.support.keysight.com/fieldfox/help/FieldFox.htm
CAT (Cable and Antenna Test) Mode - Option 305 53