User's Manual

Operation DMH Series VHF Radio
Page 3-16 BK RADIO
or priority channel if Talkback Scan is enabled, or the Priority 1 channel if TX on PR1
is enabled. To alert the user that the radio is in Unit-To-Unit Mode, a beep will
periodically sound until the unit is returned to normal Operating Mode.
If the RTX channel’s Digital Squelch Mode is set to ‘selective’, the radio will accept
group calls, correctly addressed Unit-To-Unit calls, and if RX Mode is set to mixed,
analog signals.
When a correctly addressed Unit-To-Unit call is received, the radio will beep twice. If
the calling unit’s ID matches one of the Call List IDs, the associated label will be
displayed along with the RX and phone icon. Otherwise, the numeric ID will be
displayed along with the RX, ID, and phone icon.
If the calling unit is not the same unit displayed before the call was received, the
calling unit’s ID will be displayed for the duration of the reception. The previously
displayed ID will remain the default transmit ID, but the interrupting ID will be
captured as ‘last active’. To speak to the interrupting caller, press [*] to make the last
active ID the new default transmit ID.
When a group call (or, if allowed, an analog signal) is received, the radio will display
the RTX channel’s label for the duration of the reception.
If the RTX channel’s Digital Squelch Mode is set to ‘normal’, the radio performs as
when the Squelch Mode is ‘selective’, except all individual calls will be received when
the incoming NAC matches the channel’s programmed receive NAC, not just
individual calls addressed to the unit. Individual calls not addressed to the unit will be
indistinguishable from group calls. Only the channel label will be displayed, not the
ID of the calling unit.
If Unit-To-Unit Mode is entered when the RTX channel is programmed for analog-
only transmissions, pressing PTT will cause the radio to beep until PTT is released.
The user must select a channel capable of digital transmissions before placing
a Unit-To-Unit call. If the RTX channel is programmed for Mixed Mode transmit,
transmissions will be made as digital Unit-To-Unit calls while the radio is in Unit-To-
Unit Mode, regardless of the position of the ‘TX Digital’ switch.
3.12.2 INITIATING A UNIT-TO-UNIT CALL
To initiate a Unit-To-Unit call, press the microphone’s [*] key to enter Unit-To-Unit
Mode. The label of the last active (called or received) ID will appear on the display.
If the last active ID was a Call List ID, its label will be displayed along with the phone
icon, otherwise the numeric ID will be displayed along with the phone and ID icon. If
a label is displayed, press and hold [#] to view the corresponding numeric ID.
To place a call to the displayed unit, press PTT. To choose another unit, use the
keypad to enter the desired call list entry (0 - 9), or press [PRI] repeatedly to cycle
through all call list entries, or press [#] to manually key in a new ID (up to 7 digits).
To re-select the ‘last active’ ID, press the [*] key. Once the new unit ID is selected or
entered, press PTT to place the call.
To exit Unit-To-Unit Mode, press and hold the [*] key.
3.12.3 RECEIVING A UNIT-TO-UNIT CALL
When a Unit-To-Unit call is received while the radio is in normal Operating Mode, the