Standard Horizon HX280S Owner's Manual page 15

PTT ( PUSH-TO-TALK ) Switch
When pushed activates the transmitter.
LCD Display
This display shows current operating conditions, as indicated on the page
17.
Keypad
[ 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 normal (quiet)
monitoring.
[ SCAN ( DW )] Key
Starts scanning and priority scanning of programmed channels.
Secondary use:
Press and hold the [ SCAN ( DW )] key for two seconds to activate the Dual
Watch feature.
[ ( UP )] Key
Press the key momentarily to increase the channel one step. Hold the key
down to increase the channel continuously.
Secondary use:
Used to adjust the squelch threshold level up after the [ SQL ] key is pressed.
[ ( DOWN )] Key
Press the key momentarily to decrease the channel one step. Hold the key
down to decrease the channel continuously.
Secondary use:
Used to adjust the squelch threshold level down after the [ SQL ] key is
pressed.
[ WX ] Key
Immediately recalls the last-used NOAA (National Oceanic and Atmospheric
Administration) 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 Canadian
channels.
HX280S Page 15