Keysight N9923-90001 User’s Guide 163VVM (Vector Voltmeter) Mode - Option 308OverviewOverviewIn the FieldFox, both 1-port and 2-port measurement types use a differentconfiguration setup from the HP/Keysight 8508A Vector Voltmeter.Figure 11-2 Typical 8508A measurement configuration –as shown in the 8508A manual.The above block diagram requires an exte rnal source and directional coupler tomeasure the electrical length of a DUT or cable to be trimmed. Separate pathsare used to measure the Incident signal (A) and Reflected signal (B). Tomeasure the ratio of the Reflected/Incident signals, you were required to selectB/A for both the Magnitude and Phase display.In the FieldFox, the source and directional coupler are inside the instrument.This allows you to connect the DUT to ONLY the FieldFox PORT 1, with NOexternal instruments, in order to make Cable Trimming measurements.See the FieldFox block diagram and Cable Trimming procedures beginning in“1-Port Cable Trimming Measurements ” on page 169.
