Keysight Technologies FieldFox N9912A104 User Manual page 26

Preparing for Initial Use of Your New FieldFox
Avoid Overpowering the FieldFox
Very often, coaxial cables and antennas build up a static charge, which, if
allowed to discharge by connecting to the FieldFox, may damage the
instrument input circuitry. To avoid such damage, it is recommended to
dissipate any static charges by temporarily attaching a short to the cable
or antenna prior to attaching to the FieldFox.
2- 6 Keysight N9912-90001 User's Guide