DMR Simplex

DMR Simplex

On the professional side of DMR, Talk-Around refers to operating simplex on a repeater output channel. This allows a direct communication while still being able to hear the repeater. This allows users to directly contact other users listening on the repeater output frequency. Amateurs typically use dedicated simplex channels so as not to interfere with repeaters.

The amateur DMR community has published a list of recommended simplex frequencies to be used instead of operating simplex on repeater outputs:


UHF 1) 441.000 2) 446.500 3) 446.050 4) 446.075 5) 433.450

VHF 1) 145.790 2) 145.510

[Use TALK GROUP99 / CC1 / TS1 /Admit Criteria: Always / In Call Criteria: TX or Always]

Do not use 146.520 or 446.000; they are the national analog simplex channels and operating DMR on these common analog use frequencies will just cause disharmony within the amateur community. Also, avoid 9 repeater inputs and outputs, locally used non-DMR simplex channels, satellite sub-bands, and any other frequencies that could disrupt other amateur communications.