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Simplex Frequencies & Usage

Occasionally you want to use your radio without having to use a repeater. We have that covered. You can program your radio with the following information, and use your radio in Simplex mode, no problem.

Simplex Frequencies
Talk Group 99, Time Slot 1, Color Code 1 are widely used.
Simplex Channel Frequency Admit Criteria
Simplex 1 (UHF) 441.0000MHz Always or Ch. Free
Simplex 2 (UHF) 446.5000MHz Always or Ch. Free
Simplex 3 (UHF) 446.0750MHz Always or Ch. Free
Simplex 4 (UHF) 433.4500MHz Always or Ch. Free
Simplex 1 (VHF) 145.7900MHz Always or Ch. Free
Simplex 2 (VHF) 145.5100MHz Always or Ch. Free
Please do not use the 2m (146.520MHz) or 70cm (446.000MHz) analog call channels for digital simplex, as they are not in the band plan for narrowband digital use.

The admit criteria is your choice, but this is what it means. You can set your radio’s admit criteria to always, and you can talk at any time, regardless if someone else is using the frequency/Time Slot. Setting it this way, you are unrestricted when you can transmit, but you can experience “doubling” as you would in traditional analog FM.

The setting of Channel Free will restrict you from being able to transmit until the channel is free. This will prevent doubling, but can also allow someone with a faster PTT finger to start transmitting before you, which then you will have to wait. The radio will “bonk” at you, telling you that the channel/TG is not free. There is a trade-off and benefit for each of them.

Color code free will give you the same results as channel free during simplex operations.

repeaters/simplex-channels.txt · Last modified: 2021/10/02 22:50 by Chris Cotter, KD5HIY