The instrument impedance is 50 ohms by default. This can be changed to 75 ohms by using the Anritsu external impedance converter, part number 12N50‑75B, which is designed for DC to 3000 MHz.
50 ohms
Select this impedance when no converter is used. Impedance loss is automatically set to 0.0 dB.
75 ohms
For example, select this impedance when Anritsu part number 12N50‑75B is used. Impedance loss is automatically set to 7.5 dB.
Other
Set this impedance (also 75 ohms) when an impedance converter other than Anritsu part number 12N50‑75B is used. Set the insertion loss for the impedance converter that you are using.