DMR (Digital Mobile Radio)

Digital Mobile Radio (DMR) is one of the latest commercial protocols being adapted for Amateur use. Like D-STAR, DMR is digital and repeaters are typically networked. DMR is in its infant stage. We are hoping, eventually that there will be Repeaters in the ArkLaTex that will be linked for use on DMR via the ArkLaTex Talk group (31229). Currently you can connect with individual Amateur radio operators anywhere in the world through talkgroups. The amazing thing about DMR is the audio quality is as good as talking in person. No noise or R2D2 being heard. You can literally “work the world” from you living room using a small handi talkie.

DMRis an open and published international digital radio standardthat specifies a 2 channel Time Division Multiple Access (TDMA) communicationprotocol. Each repeater has two channels – a local channel and a wide area channel.

DMR satisfies the FCC’s narrow band mandate by being 6.25 kHz wide. It is actually more spectrum efficient than other 6.25 kHz modes since no guard band is needed between the two channels. Think of DMR as 1/3 the channel bandwidth of a current 25 kHz analog signal, with twice the number of voice channels. It also offers extended battery life, and it has superior voice quality over other digital voice modes. DMR also has better RF coverage than older digital technologies.

Another advantage of DMR radios is superb RF performance. When you use a commercial DMR radio for amateur radio (such as our Motorola DMR repeater) you will notice it has better intermodulation rejection, better selectivity and less spurious emissions. It is mechanically a very well designed radio platform using forward error correction and cyclic redundancy codes. The local DMR network is connected to several networks of repeaters by the internet. You can have access to hundreds of repeaters simultaneously when you want to utilize the wide area networked time slots.

Springhill Amateur Radio Club utilizes the Brandmeister Network. Brandmeister is operating software for master computer servers participating in a worldwide infrastructure network of amateur radio digital voice systems. Brandmeister allows one to roam automatically from repeater to repeater, to make world-wide QSOs with any type of amateur DMR network, to make private QSOs on any time-slot, transmit your location to Automatic Position Reporting Systems (APRS), send and receive text messages, send and receive text messages to or from Automatic Position Reporting System (APRS), use a DMR radio as a remote control device, or to act as a Gateway for EchoLink.

Springhill Amateur radio Club is proud to be one of the first clubs in Louisiana to own and operate a wide area DMR repeater. We hope you enjoy its use. More information can be found in the subtabs of this section.