DMH Owner’s Manual
7
TRANSMIT
Press the PTT (Push-To-Talk) switch on the microphone. The
1.
TX
annunciator appears on the display and the red Transmit indicator
illuminates while the PTT is pressed.
Talk in a normal voice with the microphone approximately one to
2.
two inches from your mouth.
Release the PTT switch to stop transmitting.
3.
If the
TX
annunciator does not appear and a tone is heard, you are on
a receive-only channel or the channel is busy (if Busy Channel Lockout
is enabled). Turn the Channel Selector knob to an authorized transmit
channel or wait until the channel is clear (if Busy Channel Lockout is
enabled).
If the length of your transmission exceeds the preset Time-Out Timer
setting, the transmitter automatically shuts off and a tone sounds. To
continue the transmission, release the PTT switch, then press it again
and continue talking.
CHANNEL GUARD OPERATION
Channel Guard allows one radio or group of radios to be selectively
called within a system. If the radio has been programmed with Channel
Guard, use the following receive and transmit instructions.
ANALOG SQUELCH CONTROL
Sub-audible signaling (CTCSS/CDCSS) is used to allow a group of
radios to be selectively called in a system. Programming the receive
guard equal to zero allows for Carrier Squelch operation, where the
radio will unmute whenever a carrier is detected.
APCO PROJECT 25 SQUELCH CONTROL
Network Access Codes (NACs) provide the digital equivalent of analog
sub-audible signaling (CTCSS/CDCSS) allowing a group of radios to be
selectively called within a system.
Users in the same area (using the same NAC) can be further divided
into Talk Groups, with each group having its own Talk Group ID (TGID).
Group Calls are made by designating both the users’ NAC and TGID.
Each radio also has an individual P25 unit ID. A Unit-to-Unit call contains
the addressee’s NAC, and uses the addressee’s P25 unit ID instead of
the TGID.
