10
Northstar
Explorer VHF Series: 721/725
Operation and Installation Manual
Northstar
Explorer VHF Series: 721/725
Operation and Installation Manual
1-6 How the Microphone and 701 Optional Handset Work Together
Consult the 721/701 Quick Start Guide for additional operational instructions.
If you have the optional 701 handset installed on your VHF721:
• neither item will transmit while both are ON hook, but you can hear the audio from the handset
speaker and adjust the handset volume.
• to use one item when it’s OFF hook, the other item must be ON hook.
• if both items are OFF hook, only the microphone works.
• in Intercom mode ONLY, both items work OFF hook.
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.
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 con-
nected.
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 (e.g. 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 . 721/725US 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 . 721/725EU 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 chan-
nel.