32• EmergencyRefer to “EMERGENCY CALLS” on page 25.• External SpeakerPress this key to switch the speaker from the transceiver’s built-in speaker toan optional external speaker. When using an external speaker, the(KCH-4) or SP (KCH-5) icon appears on the display.• FunctionPress this key, then press a programmable key to activate its secondaryfunction.• GPS Position DisplayPress this key when the GPS unit has been installed to display your locationdata.• Home ChannelPress this key to jump to your home zone and channel (pre-programmed byyour dealer). If activated by your dealer, you can set your own Home Channelby selecting your desired zone and channel, then pressing and holding theHome Channel key for 3 seconds.• Horn AlertPress this key to toggle the Horn Alert function ON and OFF. “HORN ALERT”appears on the display when Horn Alert is activated. When a call is receivedthat has a correct DTMF code or 2-tone signaling, Horn Alert causes thevehicle horn or some other external alert to sound.• IndividualRefer to “Making Individual Calls (P25)” on page 3.• IntercomPress this key to toggle the Intercom function ON and OFF. “INTERCOM”appears on the display when Intercom is activated. To use the Intercom function,your dealer must first install a dual-head (microphone and speaker) system.When making a call, your voice will be transmitted over the speaker system.• Key DeleteRefer to “DELETINg ThE ENCRYPTION kEY” on page 27.• LCD BrightnessPress this key to change the brightness level of the LCD. Each time this key ispressed, the brightness levels cycle as follows:High Mid Low Off• MonitorPress this key to turn the transceiver signaling off, to listen to all calls that arereceived on the channel. While monitor is activated, the (KCH-4) orMON (KCH-5) icon appears on the display. Press the Monitor key again toturn the transceiver signaling back on.Press and hold this key for 2 seconds to turn the transceiver squelch off, tolisten to weak signals on the channel. While squelch is off, the (KCH-4)or MON (KCH-5) icon appears on the display. Press the Monitor key again toturn the transceiver squelch back on.