Press the Span main menu key to access the Span menu. Then press the Zero Span submenu key to select Zero Span. If Option 89 is installed on your instrument, then press the Zero Span submenu key again (after the circle is red) to access the Zero Span IF BW menu. The span can be set from 10 Hz to maximum frequency of the unit. The Span can also be set to zero span.
Key Sequence: Span > Zero Span
Zero Span IF BW Menu
Normal
Press this button to select a bandwidth that uses bandpass filters in the normal RBW chain. When this button is pressed (red circle indicates active setting), the IF bandwidth is influenced by the selection of RBW filters.
7 MHz BW
Press this button to select a fixed IF bandwidth of 7 MHz.
10 MHz BW
Press this button to select a fixed IF bandwidth of 10 MHz.
16 MHz BW
Press this button to select a fixed IF bandwidth of 16 MHz.
32 MHz BW
Press this button to select a fixed IF bandwidth of 32 MHz.