User`s guide

3-10 User’s and Service Guide
Controlling the Test Set and Making Measurements
Calibrating the Test System
CAUTION When performing a full two-port calibration and making subsequent
measurements, you must use the transfer switch internal to the 8720D
to change the RF signal path direction. Do not use the test set to change
the RF signal path direction when you are using a full two-port
calibration. Doing so will render the calibration invalid.