8
RELM/BK Radio
When operating in Digital Mode, each channel can be programmed to
use either Normal squelch or Selective squelch.
Normal Squelch
1.
Normal squelch is used to mimic analog operation. Signals are
only qualified with the programmed NAC. TGIDs and P25 Unit IDs
are ignored. Each digital channel is programmed with a receive
NAC and a transmit NAC. When an incoming signal’s NAC matches
the channel’s programmed receive NAC, the radio unmutes. The
default NAC is 659 ($293 hex). The digital equivalent of carrier
squelch is achieved by programming the receive NAC = 3966($F7E
hex) the radio will unmute when a digital signal with any NAC is
detected. The 3966 ($F7E hex) NAC is reserved for receivers and
is not allowed as a transmit NAC.
Selective Squelch
2.
Selective squelch is used for processing ‘Group Calls’ and ‘Unit-
to-Unit Calls’. TGIDs are assigned on a per-channel basis. Users
can be separated into Talk Groups with each group having its
own TGID. Then, on channels programmed for Selective squelch,
the incoming signal’s NAC and TGID must match the channels
programmed receive NAC and TGID for the radio to unmute. The
default TGID is 1. The TGID value 65535 ($FFFF hex) is used to
effect an “All Call”. If the radio receives a signal with a matching
NAC and the TGID = 65535 ($FFFF hex), it will unmute. Also, if
the radio’s programmed TGID is 65535 ($FFFF hex), it will open
on any signal with a matching NAC, ignoring the incoming TGID.
A TGID = 0 means “no one”. If the radio is programmed with the
TGID = 0, it will accept incoming group calls containing the “All
Call” TGID, and correctly addressed Unit-to-Unit calls.
CHANNEL GUARD RECEIVE
Turn power on by pushing and releasing the Volume knob. The
1.
radio will beep, indicating that it has passed its self test and is
operational.
Set volume by pressing the
2.
[MON]
button to hear squelch noise.
Turn the Volume knob to set a comfortable volume level. Press
the
[MON]
button again to stop squelch noise.
Select a channel group (if applicable) by pressing the
3.
[GRP]
button and turning the Channel Selector knob. Press the
[GRP]
button again to return to Channel Select mode.
