RELM WIRELESS CORP. - BK RADIO KNGM150LP User Manual

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When operating in Digital Mode, each channel can be programmed to use either 

Normal squelch or Selective squelch.
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 293 (0659 decimal). 
The digital equivalent of carrier squelch is achieved by programming the receive 

NAC = F7E (3966 decimal). The radio will unmute when a digital signal with any 

NAC is detected. The F7E (3966 decimal) NAC is reserved for receivers and is not 

allowed as a transmit NAC.
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 FFFF (65535 decimal) is used to effect an “All Call”. If the radio 

receives a signal with a matching NAC and the TGID = FFFF (65535 decimal), it will 

unmute. Also, if the radio’s programmed TGID is FFFF (65535 decimal), 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 only.