DMR is a digital voice mode originally designed for commercial use but has been adapted for amateur use. Adoption of DMR by amateurs has been gaining speed lately, most likely fueled by the availability of inexpensive radios from various sources.
Getting Started with DMR
The first step, as with any digital mode, is getting a compatible radio. With DMR you have a few more "budget" choices compared to the other digital modes, which is one of the factors driving its popularity. At the bottom of this page you will find three such examples. The TYT-MD380 is a great place to start to find out if DMR is for you. After you have the radio, you will need to program it, more on that to come.
Before you can program your radio, you will need a DMR-MARC ID. To get your ID, visit the DMR-MARC Registration page.
Program the Radio
Configuring your "codeplug" (DMR speak for the configuration of the radio) can be complicated, but thankfully there is help. To get started quickly, there are a couple of places where you can get preconfigured codeplugs for "plug and play" operation. In my area, you can visit Minnesota DMR for the TYT radios (and variants), or MNDMR.net for Motorola radios.
This is where things can get rather interesting. There are several DMR networks that carry the talkgroups between repeaters and hotspots through an Internet connection. There is CBridge, DMR+, Brandmeister, and probably others that I'm not aware of. From what I have learned by listening so far is that some talkgroups are shared between these networks. To dig deeper into this, I will refer you to the links section below.
The XLX multiprotocol reflectors are capable of transcoding between DMR and D-STAR. One such example is XLX313, hosted by the "King's of Digital". The following are instructions for using a hotspot with XLX313, originally posted to Facebook by Todd N6XDX.
Instructions for connecting to XLX313 via DMR.
To connect to XLX reflectors via DMR, you must be using an image that contains DMRGateway (Pi-Star or the KB5RAB image) or with the SharkRF OpenSpot.
Using Pi-Star follow these steps:
- From the web interface, go to the Configuration page.
- In DMR Configuration section, change the DMR Master to DMRGateway, click apply changes.
You can now make the following changes:
- Select you Brandmeister Master
- select a local DMR+ Master
- set XLX Master to XLX313
- optional to select a Startup TG, if none is selected you will need to select the TG from the radio.
- enable XLX Master Enable
- DMR Color Code is your current configuration
- Apply Changes when finished.
- If you will not be using the DMR+ network go to go to http://pi-star/admin/expert/ and select DMRGateway for editing.
- scroll down to DMR Network 2 section and change Enabled to 0 to disable.
DMRGateway basically acts as a switching network between the Brandmeister, DMR+ and XLX systems. To differentiate between Brandmeister and XLX TG’s, the XLX TG’s are transmitted on TG6. You should have the following contacts and channels programmed into your radio:
- TG6 Group Call for transmit and receive on the XLX TG’s.
- 64000, Private Call, XLX Disconnect module command
- 65000, Private Call, XLX Status command
- 64001, Private Call, connect to module XRF555A
- 64003, Private Call, connect to module XRF555C
NOTE: XLX313 has 6 modules that can be used. 4001 – 4006 relate to Modules A – F, all of which provide transcoding. These numbers are preceded by a 6 so DMRGateway knows to route the command to the XLX. Be sure to have TG6 in the RX group so you can hear connect, disconnect, and status announcements from your hotspot.
When you have connected to the desired module, change you radio channel back to TG6 to transmit and receive (similar to changing reflectors on D-Star).
Additional info can be found at http://xrefl.boards.net/…/39/connecting-mmdvmhost-dmrgateway
To connect via the SharkRF OpenSpot:
The following instructions are from http://xrefl.boards.net/thread/40/connecting-openspot, assumes modem already set for your radio.
- Connector: Homebrew/MMDVM (May need to check Advanced Mode at the bottom to see all fields.)
- Quick Call: 4000 Disconnect, Destination 4000, Group Call
- DMR/Homebrew/MMDVM: Set frequency fields, Protocol MMDVM, Server* xlx313.openstd.net Port 62030 Set Callsign and DMR ID. Leave other fields as is and save configuration.
- All following on Slot 2. openSPOT reports status in TG 9
- Disconnect TG 4000 TG 9 in Rx Group
- Status TG 5000 TG 9 in Rx Group
- Connect to 4001 set TG 4001 TG 9 in Rx Group
- Connect to 4006 set TG 4006 TG 9 in Rx Group
- Talk set TG 9
- *Depending on the openSPOT firmware version, alternate means to address the server may be needed. Alternate: Use IP address 220.127.116.11
You should have the following contacts and channels programmed into your radio:
- 4000, Group Call, XLX Disconnect module command
- 5000, Group Call, XLX Status command
- 4001, Private Call, connect to module XRF555A
- 4003, Private Call, connect to module XRF555C
NOTE: XLX313 has 6 modules that can be used. 4001 – 4006 relate to Modules A – F, all of which provide transcoding.