DMR – Digital Radio

Madison Amateurs - Doing what is needed when Needed

DMR – Digital Radio

by WA1TCC

Madison’s VHF repeater has been changed to Brandmeister DMR repeater. It is currently setup without internet connectivity. The local talk group 9 is functional. The settings are listed below. Anyone is welcome to use it and we appreciate reports of the foot print.

Input 442.000 Output 447.000 CC 1 Slot 2 Talk Group 9

DMR Setup


 DMR setup can be intimidating. You do not have to learn all the options to get started. Find out the frequency of the repeater, the color code, and the repeater slots that are used and the talk groups assigned to each. Below are the basics for configuring a DMR Transceiver. It is only the basics of DMR. Each Transceiver will have different options for the model. Information on specific models will be added when available. DMR is setup with a number of parts. It is confusing at first but becomes easy once your needs are understood and how to put those parts together.

 The parts are:
 • Contacts
• Talk Groups
• Channels
• Scan Groups
• Receive Groups
• Zones

Contacts

Contacts are for digital references. On some radios you can import a full list of all the possible contacts that have digital IDs where on others like the Baofeng only a subset can be imported from a CSV file. Each Radio Amateur needs a DMR ID on the transceiver. When transmitting the ID and call sign are passed through the digital connection Depending on the configuration and radio, the call sign, the name and/or the digital id can be seen on the radio. Most radio allow for a separate listing for your convenience of keeping track of your local contacts. At the first configuration of the radio, the owner’s call sign is entered and a download or the latest list of DMR IDs is added to the digital ID contract grouping.

Talk Groups


A talk group is a configuration set up for all repeaters to use. A complete list of available talk groups can be obtained from the central servers that are used by DMR. Links to groups are below. A talk group is a dedicated group that the DMR server uses to sort traffic to members of that group. If you want to talk to someone about a specific topic you will find a talk group for that topic. Once it is chosen and added to the radio you will be able to call out and find users that are interested in that topic. The repeater has by default the local talk group that acts just like an analog repeater. Local uses can talk to each other within the range or the repeater. When the DMR repeater reads the requested talk group as being local it will only broadcast by radio. This limits the access to the range of the repeater using the radio range and signals. Other talk groups are shared within the DMR world. Traffic coming in listing these talk groups is sent into the Internet to the DMR servers to connect to anyone else that wants to use that talk group. This is the difference with analog receivers and digital receivers that must be understood to effectively use DMR. There are thousands of talk groups that cover a wide range of topics. They can be connected to with a simple DMR radio and a connection to either a DMR repeater or a hotspot (discussed below). An analog repeater can only talk to the local listeners. So, download the list of available talk groups and review them. It is easier to decide the ones that you will be interested in, add them to the radio rather than adding several thousand, and have to manage that large number when setting up the radio. Once you have the talk groups on the radio you need to go to the next step.

Channels


The channels allow you to use your radio just as you would with analog repeaters but you get many more options in the digital world. A listing of channels can be analog as well as digital repeaters and simplex frequencies. Analog repeaters will have one listing. You will configure it just like any radio using a PL tone and a send and receive frequency. A DMR Channel is associated with a talk group. This allows the repeater to understand whom you want to talk. So, for every DMR repeater you will add an entry that also lists the talk group. This can add up to a large number of entries if you use multiple DMR repeaters. Best to do it with a spreadsheet and import it using the appropriate software. Channel 1, 2, and 9 are the standard for local repeater radio only connections with 9 being the most commonly used connection. . Be aware that if Channel 9 also has any other group available on its slot, you may have to wait for that channel to finish before getting access. The digital radio can have a large number of potential channels setup for communications. Start with the basics, listing your analog and digital repeaters in an order that makes sense to your use. Do not forget to add simplex channels for analog as well as digital usage. Later you will be using zones to manage your entries but at this time it makes sense to keep things in order. Setting up a DMR channel is not difficult but more information is required than an analog connection. When setting up for a DMR connection in a radio you will need the frequency of the repeater – both receive and transmit frequencies and the color code (think of the PL in analog world). The color code is an older term and each color has a number. You just need to know the number 1-15 and add that to the channel entry. Also, a new term is the slot number. DMR repeaters have two slots 1 and 2. Each carries data separate from the other. More details on how it uses these slots later. All that is necessary is to understand them as two separate channels into the repeater. Each has to be programmed into the channel. Many repeaters use a specified slot for talk groups. Talk group 9 local and maybe another talk group is added to one slot by the admin and all other talk groups go out through the other channels. That involves repeater management. You need to find out what is assigned to the repeater and configure each channels with the appropriate information.

Scan Groups


After setting up the channels you can start to make specific use of the channels. One option is to begin creating groups. A scan group is a number of channels that you want to be able to scan. The scan group is associated with a channel. So when the radio is on a particular channel and you turn on scan, it will scan the group associated with that channel. Think of the uses. You can scan your emergency channels while monitoring the local repeater. One use of this setting is to include emergency channels in with the standard use repeaters and not allow any signal to be broadcast on an emergency channel while scanning. There are other options too. Use it as you need and a new scan group can always be added later if needed.

Receive Groups


Receive Groups are a set of talk groups that are setup to allow the radio to scan those groups when on a particular channel. This allows the radio to be on a particular talk group but allowing monitoring of a number of other talk groups on that repeater.

Zones


Zones can be scary but are simply a way of keeping the world in order. Mostly you will forget what each does if you do not use them frequently. Label each to reflect how you will remember what its use is. The zone is a container for whatever channels you want to group together on your radio. Here in Florida we have the SAR net of UHF analog repeaters across the state. If traveling, the range of each repeater is limited, but with a full listing, communications is possible throughout the state by changing to the next repeater. These SAR net repeaters are all in one zone simplifying the use of the SAR net. A channel can be in any number of zones. Set up zones for communications to fit the style of your work. Emergency channels and public service can be listed in one zone. Local repeaters both analog and digital can be in another zone. Setup any number of zones as needed. You can setup a zone of related talk groups from the same or different repeaters. It is all in how you want to organize your world of radio.

Links to DMR resources

https://hose.brandmeister.network/
 http://dmrx.net/dashboard/dmrx-dashboard-DMR-SE.html
http://www.trbo.org/cBridge/netwatch.html


The link below will show the usage and the active Talk Groups on a repeater when it is connected to the Internet

DMRX Dashboard


In the following page we will provide information for the setting up DMR and code plugs. If you have a code plug for a specific model you can send it to me. I will post them on this page.

DMR Setup
 http://www.miklor.com/DMR/ppt/DMR-BasicTutorial.pdf


The file below is a CSV file exported from a Baofeng DM-5R that lists all the local repeaters and all SAR net repeaters.
It can be used with cleaning to load on your HT with Chirp.


Below is my ANYTONE code plug and the various components in separate csv files for editing and loading into your CPS software. This information is focused on the North Florida region comprising Madison and the counties next to it.
Anytone 578 Code Plug
Anytone 878 Code Plug
Channels.csv