Hello and welcome to DMR Montana - a place where the Mac Pass Repeater Group (MPRG), a Helena-area amateur radio club, shares information on its DMR activities and much more. This includes what we are doing in the field of digital communications and also what other Montana hams and clubs choose to share with the community.

Do you have a D-Star, Fusion, NXDN, DMR, P25, Tetra, or other such digital repeater on the air in Montana? Take a look at the Helena Mac Pass DMR page then send me the same information about your repeater. I will create a page about it.

There is a knowledge barrier to entry for DMR. Unlike your analog FM ham rig, DMR radio programming can be overwhelming unless you have experience with trunked radio or complex conventional radio programming. Many ham DMR organizations provide basic radio programming files (code plugs) to get the new to DMR ham started and that too is our intention. On the Downloads page, we will make available basic code plugs for radios that we have experience with to jump start your entry toward operating on our DMR repeaters.

The second issue that can be a knowledge barrier to understanding DMR is the concept of talk-group-based communications. In DMR 101, we will help you understand talk-groups. Short version, its less about selecting a specific repeater frequency and tone and more about selecting the group of people that you want to talk to. Understanding talk-group-based communications is important for operating your radio and is also important to know before you can programming your radio.

Major change in the technologies that we hams use happens infrequently. CW to AM to SSB. AM to FM. Tubes to semiconductors. Today, we might want to move our repeaters from analog FM to one of the digital ham radio-specific technologies or to one of the narrow-band technologies currently in-use by the Part 90 world. Now is your chance to learn about several different narrow-band digital technologies, experiment with the ones that interest you, then make your informed opinion heard to the greater amateur radio community.

I say “might” because in Montana, there isn’t a strong need for narrow banding our repeater spectrum. There is a performance hit associated with narrow-band digital radio modulation schemes. But, digital radio brings abilities that are not easy to do or not able to do when using analog FM. We of the MPRG intend to implement and learn by using DMR on UHF in our real-world diffraction and multi-path filled environment. We need the answer to the question, “is digital good enough?” We also have a 2 meter Fusion repeater for use as a learning platform. It will be at least a year before we decide if the disadvantages of digital outweigh the advantages of analog. Then, there is the decision of which digital scheme makes sense for us but we are not hiding our affinity toward talk group-based communications, which means DMR. We could decide digital repeaters do not makes sense at which point, we will lock down the ones we have to FM-only. Or, we might decide that digital pros outweigh the cons and order six more DMR repeaters to replace all of the MSF-5000 stations at all of our repeater sites.

Before you proceed down the DMR highway, we need to set some expectations so as to avoid anger and frustration. Change will be frequent and involve the use of computers. You will be fine-tuning the configuration of your new radio constantly so it behaves just the way you want. Radio equipment manufacturers will occasionally release new firmware versions for repeaters and subscriber equipment. They will also release new versions of radio programming software. You might be able to skip some software/firmware upgrades but will be forced into others. The world-wide network of repeaters that we intend to join is 100% a creation of ham radio operators who are also talented software developers. The network is early in its life so there are frequent upgrades to it. If you intend to operate a DMR hotspot (RaspberryPi/DVmega radio/mmdvmhost software), know that mmdvmhost is under active development and that source code changes are posted almost every day. What hasn’t changed is your new DMR repeater needs to be free of desense and intermod to operate effectively. Your new DMR mobile still needs a clean source of DC power and its antenna still needs to be tuned and have a properly installed connector on the end of the coax cable. With digital modulation masking the familiar symptoms of these common radio issues, you will need new troubleshooting skills to chase after these old problems.

We hope that putting forth the effort to learn a new technical field and trying new radio technologies is attractive to you as a ham. Please join us in this adventure.

For the Mac Pass Repeater Group,

Mike KB8ML


Early adopters in Helena include:
Tom WR7AGT
Don W7MRI
Bill K7MT
Darrell K7IUI
Scott N7KJ
Dale KA7MHP
Mike KB8ML [email protected]

In addition to DMR talk groups Montana Statewide 3130, MPRG1 31301, and MPRG2 31302, you can find us via our EchoLink-based UHF repeater network.

Mac Pass (Helena) 444.1+ PL 131.8
North Hills (Helena Valley + Downtown & State Capitol Complex) 448.9- PL 131.8
Boulder Hill 449.2- PL 131.8
Toston (Townsend, Toston, Three Forks, Bozeman) 449.3- PL 131.8
Badger Pass (Dillon) 444.1+ PL 100.0
University Mountain (Missoula) 448.9- PL 131.8
Lookout Pass (Superior, St. Regis, I-90 west through Idaho to Spokane) 444.2+ PL 131.8


System-wide UHF DMR coverage map
System-Wide UHF DMR Coverage Map v4