Keysight A Series User Manual page 594

VVM (Vector Voltmeter) Mode - Option 308
1-Port Cable Trimming Measurements
9. Remove the reference cable from the FieldFox PORT 1 connector.
10.Connect an unterminated, longer cable to the FieldFox PORT 1 connector.
11.Observe the displayed phase difference between the reference cable and
The VVM phase reading shows a maximum of ±180°. Therefore, the
electrical length of the untrimmed cable MUST be within 180° of the
reference cable.
12.Carefully trim the cable until the phase shift reads zero. The attached
13.Repeat steps 10 through 12 for the remaining cables to be trimmed.
594
the untrimmed cable.
cable's electrical length is now matched to the reference cable.
Keysight N9927-90020 User's Guide