I wanted to post a short blog about DMR that I have used to help explain it to new folks in teh hopes that some might find it useful. It does not go into depth, but that can certainly be a followup for any that are interested.

DMR is similar to analog repeaters, but it involves sending digital voice over the radio. This allows two conversations to use the same repeater at the same time, as well as allows communication within 100’s of different talk groups through that repeater. Additionally, DMR repeaters all over the world are linked together so you can talk to people all over the world.
I will try to explain it without getting into the technical details. It may seam complex at first, but know we are hear to help. What I describe below is an introduction to the practical side of DMR and does not go in depth of the specification or how repeaters work.

Like using any repeater, you need to know the frequency for transmit and receive for that particular repeater and have your radio setup for that frequency. The difference between an analog repeater and a DMR repeater is that for DMR you additionally choose a talk group you want to participate in on the DMR network as part of your setup. A talkgroup can be thought of as a virtual room for people to get in to talk to each other. DMR allows thousands of talk groups to all work on the same frequency of the repeater. Talk groups are specified by a number within the radio, but they also have names. These are defined on the DMR network and are the same worldwide and they do not change. For example, The Arkansas statewide is 3105 on the brandmeister DMR network. Each state has a statewide talk group. You can chose to use that talk group on any DMR repeater anywhere in the world and it will communicate with any other DMR repeater that is also participating on that talk group. You can look up these talk groups on the DMR network providers website. For brandmeister this can be found at: https://brandmeister.network/?page=talkgroups

The interconnectivity between all DMR repeaters across the globe makes it easier to talk to people anywhere DMR reaches. I often hear people from Australia, China, and Europe on DMR talk groups. I will not get into how a repeater handles having thousands of talk groups available in this discussion, but know that at any given time a repeater will only have a few talkgroups active at a time. To activate the talkgroup you want to use, you set your radio for that channel (repeater frequency+talk groupID) and key up the radio. This instructs the repeater to start participating in that talkgroup.

Using a DMR radio;
Within the DMR radio and the programming you will have zones and channels. The pairing of the talk group and the repeater frequency is what makes up a channel. If you want to use talk group 3105 on the Conway repeater, you create a channel and specify the Conway repeater frequency, and the 3105 talk group ID. If you want to use that same talk group on the Little Rock repeater, you define a channel that specifies the Little Rock repeater frequency and the talk group ID 3105. Thus you may end up with many channels defined, with multiple channels for the same talk group ID with one for each repeater you plan to use in your travels. To make it simpler to manage, these channels are grouped in what is called a zone. The channels you put in a zone are up to the user, and the same channel can be in multiple zones. Many users like to group the channels into zones by repeater as this makes it easier to think about so that you select the zone based on your geographic location and which repeater you are going to be using.

The way to operate a DMR radio is very similar to using an analog repeater but with an extra step. You tune your analog receiver to the local repeater frequency you will be using and can then talk to anyone on that repeater, or other repeaters it is linked to. With DMR, you select the group of channels for the local repeater you want to use, then select the talk group you want to use within that group (zone) and can then talk to anyone else in the world that is also on that talk group.

This may seam very complex at first, but there are people in the club that are willing to help you get setup and on the air, and will take you technically through the programming as far as you want to go. -Daniel

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