XV-400 Operating Manual.doc Operation Quick Start To turn the radio on, press and hold the orange PWR button for 2 second. Pull and turn the top panel's CH selector knob to choose the desired operating channel, Rotate the top panel's VOL knob to set the volume level. If no signal is present, press the MONITOR button (the middle button on the left side); background noise will now be heard, and you may use this to set the VOL knob for the desired audio level.