Operating instructions

Operation DMH Series VHF Radio
BK RADIO Page 3-17
3. Press and hold the [PRI] button for more than 1 second. A short beep sounds
and PR appears in the display, indicating that the displayed channel is now the
priority channel.
NOTE: If the radio is programmed for Dual Priority operation, only Priority 1
channel can be changed with the [PRI] button.
NOTE: A channel can be the priority channel even if it is on the Scan List. Due
to multiple sampling of the same channel, however, maximum
performance occurs when the priority channel is not on the Scan List.
3.13 UNIT-TO-UNIT CALL
P25 Unit IDs allow for Unit-To-Unit calls when the radio is operating in Digital Mode.
The microphone’s [*] key must be enabled by radio programming to allow this mode
of operation. To view the radio’s ID, press and hold the [*] key while not in Unit-To-
Unit Mode. (Unit-To-Unit Mode is indicated by a phone icon in the upper right corner
of the display). Channels programmed for analog only operation will not be able to
transmit or receive Unit-To-Unit calls.
3.13.1 UNIT-TO-UNIT MODE
When the radio is in Unit-To-Unit Mode, all scanning functions will be disabled. The
radio will receive and transmit on the Ready-to-Transmit (RTX) channel only.
Depending on programming, the RTX channel can be the main channel, a held scan
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