Standard Horizon HX850S Owner's Manual page 17

PTT ( Push-To-Talk ) Switch ( Left side )
When pushed activates the transmitter.
DISTRESS Key ( Right side )
This used to send a DSC Distress Call. To send the distress call, refer to
section "7.3.1 Transmitting a DSC Distress Alert".
Keypad
[ VOL ] Key
Press this key to activate the volume adjusting mode. Press the [ ] or
[ ] key to adjust the receiver audio volume level.
[ SQL ] Key
Press this key to activate the squelch adjusting mode. Press the [ ] or
[ ] key to adjust the squelch threshold level.
Press and hold this key for 3 seconds to open the squelch, allowing
you to monitor the operating channel. Release the key to resume nor-
mal (quiet) monitoring.
[ ( UP )] Key
This key is used to change the operating channel, receiver volume
level, and squelch threshold level.
Press the key momentarily, the channel (or level) increases one step.
Holding the key, the channel (or level) increases continuously.
[ ( DOWN ) Key
This key is used to change the operating channel, receiver volume
level, and squelch threshold level.
Press the key momentarily, the channel (or level) decreases one step.
Holding the key, the channel (or level) decreases continuously.
[ WX ] Key
Immediately recalls the last-used NOAA Weather Channel from any
channel location. Recalls the previously- selected working channel when
the [ WX ] key is pressed again.
Secondary use:
When the [ 16/9 ] key is held and the [ WX ] key is pressed, the radio will
change the marine band between the USA, International, and Cana-
dian channels.
HX850S Page 17