NorthStar Navigation Explorer 721US, Explorer 721EU Basic Operation and Key Functions

1-7 Basic Operation and Key Functions

All possible keys on the base unit, the microphone, and the optional handset are listed and their functions are explained.

NOTE: Some keys or functions may not be available on your particular model of base unit, microphone, or optional handset. This example shows the 721US base unit.

Explorer 721

Key	Function
VOL PWR	Volume and Power. Turn clockwise to power on. Continue to turn until a comfortable
	volume is reached. VOL/PWR will also adjust the settings of an external speaker, if
	connected.
SQL	Squelch or Threshold Level. Sets the threshold level for the minimum receiver
	signal. Turn fully counterclockwise until random noise is heard, then turn slowly
	clockwise until the random noise disappears. Make another 1/4 turn clockwise for
	best reception in open sea conditions.
	In areas of high noise (eg close to large cities) reception may improve if sensitivity
	is reduced. Either turn SQL slowly clockwise or use the LOCAL setting. See section
	2.4.
DISTRESS	Send DSC Distress Call. See Section 6.
16/9	Priority Channel. 721US only. Press to cancel all other modes and to tune into the
	priority channel. Press again to return to your original channel.
	The default is Channel 16. To make Channel 09 the priority channel, hold down 16/9
	until a beep sounds and 09 is displayed.
16	Priority Channel. 721EU only. Press to cancel all other modes and to tune into the
	priority channel, Channel 16, on high power. Press again to return to your original
	channel.
3 CH	Three Favorite Channels. Press to toggle between your favorite channels. The
	CH1, CH2, or CH3 symbol appears on the LCD to show which favorite channel is
	selected.
	To scan only one of your favorite channels, press 3CH then immediately press and
	release SCAN. If you want to scan all three favorite channels, press 3CH then im-
	mediately press and hold SCAN.

10 Northstar Explorer VHF Series: 721US, 721EU Operation and Installation Manual