Press to set the FM audio spectrum span. Use the numeric keypad, the rotary knob, or the arrow keys to set the value. Valid values are 2 kHz, 5 kHz, 10 kHz, 20 kHz, 70 kHz, and 140 kHz.
Press to set the sweep scale in percent of intermediate frequency bandwidth (IFBW). Use the numeric keypad, the rotary knob, or the arrow keys to set the percent value.