Digital Radio

This is a coming page. We have been involved in FT8 and other digital methods and now that Madison has a DMR repeater we now monitor that frequency. More details and information  to come.

Starting With DMR

Madison has a DMR repeater on 442.000 white. It is centered in downtown Madison and is reachable throughout the county. At this time we have local 9 active and some Internet access which is relying on a hotspot for connectivity. We do not guarantee and other group since this connection is up and down. We are looking for a long time resolution to this issue

Input 442.000

Output 447.000

CC White – 1

Slot 1 & 2

DMR Setup

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 for which channel.

Setup a digital contact for the local channel 9

Setup a channel for the local repeater and Channel 9

Start sending and get on line with the locals and get help as you progress.

Madison is seeing great coverage for our digital repeater – better than we had with the analog repeater at the same location.

Go to the links below and read and familiarize yourself with the basics.

All the links below will open the page to that subject. We have included some general information on how to use the option in setting up a DMR radio. Links for specific information or information related to the topic will be on the bottom of that page. At the bottom of this page general DMR links have been added.


Madison ARC has converted our analog UHF repeater to a DMR UHF repeater using the same frequency. All Amateurs are welcome to use the repeater. At this time we have limited Internet capabilities but are working on the connectivity.

DMR repeaters use channel 9 as a local repeat channel. Other channels which go to the Internet and connect to other repeaters are setup by the administrator and use Internet connectivity to transfer the DMR data. Depending on the configuration you may talk to someone in any place in the world using the local repeater once there is a Internet configuration.

When setting up for a DMR connection in a radio you will need the frequency of the repeater and the color code ( think of the PL in analog world). You will need the offset which is usually the standardized for the frequency.


We will list known transceivers that have proved useful for the MARC here.


Contacts are for digital references. Create a contact for each of the channels you will be using. An example of the local connection is below. On some radios you can import a full list of all the possible contacts that have digital IDs where on others like the Baofeng shown only a subset can be imported from a CSV file. You get the name and call sign of the contact when talking depending on the configuration and radio.

Talk Groups

A talk group is a configuration set up for all repeaters to use with a shared name. the repeater has by default the local talk group which limits the access to the range of the repeater using the radio range and signals. Other talk groups are shared and communicate to centralized servers for distribution to repeaters that have joined that talk group. Access to the talk group is set by the local administrator and assign to one of the two channels.

RX Groups

RX – Receive Groups are a set of channels that are setup to allow the radio to scan those groups. Within the configuration the radio can send only on the received channel or set to a specific channel. 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. This setting is not configured in the RX group but in the scanning group.


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. The zone is a container for whatever connections 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 are all in one zone simplifying the use of the SAR net.

Group all the local repeaters in another zone. Put all digital repeaters in a zone. A repeater can be in many zones – it is how you have every thing at your change of zones! Experiment!


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. The screen shot below is of the Madison repeater and connecting to it for local communications. Channel 9 is the standard for radio only connections. 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.