We’ll be back on Brandmeister talk group 3126 statewide Michigan for the first DMR Tech Net of 2024 on Monday, January 8th from 7:30pm ET – 8:30pm ET, discussing the Digital Mobile Radio primer. We’ll explain the who, what, where, why, and how of Digital Mobile Radio. Whether you’ve been using DMR for a while or just getting started, join us as we go over Digital Mobile Radio from the ground up. We originally made this presentation on April 14, 2023 to the Central Michigan Amateur Radio Club but have updated it.
You can always chat with the DMR Tech Net team on TGIF talk group 31268, the DMR Tech Net channel!
If you have a comment or a DMR topic idea for the DMR Tech Net, please share it with any of us by sending an email to: steve@dmrtechnet.net, stan@dmrtechnet.net, tom@dmrtechnet.net, dana@dmrtechnet.net, brian@dmrtechnet.net, or brad@dmrtechnet.net. If you want to subscribe to this newsletter, send an email to subscribe@dmrtechnet.net.
Here are the DMR nets we’re aware of in Michigan.
Please join in & participate with them.
If you know of other Michigan DMR nets, please let us know.
Saturday:
- 7:00pm Arrow DMR Net on BrandMeister talk group 3126
- 7:30pm DMR Trivia Net on TGIF talk group 31268
Sunday:
- 6:30pm UP Net on BrandMeister talk group 31268
Monday:
- 7:30pm DMR Tech Net on BrandMeister talk group 3126
- 8:30pm Michigan One DMR Net on BrandMeister talk group 3126
Digital Mobile Radio (DMR) Primer
January 8, 2024
- Tom Janke N8TJ
- Stan LaMuth WB8QJZ
- Steve Sutton KC8WXM
- Dana West KCØMYP
- Brian Vissers KE8NJT
- Brad Freeland KE8WNV
- https://dmrtechnet.net/
To begin with DMR, you need an FCC license for Amateur (HAM) Radio –and to get that you will need an FRN number as that is the way that the FCC looks at individuals. https://www.fcc.gov/wireless/support/universal-licensing-system-uls-resources/getting-fcc-registration-number-frn
Then you will need to study for and take 1-3 test(s) for your License (Tech, General, Extra) www.HamExam.org and www.HamStudy.org
You may take all the exams at once or progressively over time. Volunteer Examiners who already are HAMs (VE’s) administer the tests. After passing the test(s), a Call Sign is assigned to you within 1-3 weeks.
Once you have an amateur license (DMR is fully available to a Technician or above), you will need to register for a DMR ID (can be issued the same day or take up to 3 days to receive) at www.RadioID.net. You will need to have a copy of your FCC license so you can upload it to RadioID.net. There is no cost for a DMR ID.
With your CallSign and DMR ID in hand, you can then go out to the BrandMeister (BM) website and sign up for an account there. https://brandmeister.network/
Once you are notified that you are active (this is a voluntary organization and so it is not necessarily quick, although it usually is same day), you will want to go to the Self-care tab (after you log in at the Brandmeister website) and turn ON your HotSpot security and create a HotSpot Security Password (different from your BM password –think simple, ie., all uppercase, or all lowercase. or all numeric -one or the other/not mixed).
DIGITAL MOBILE RADIO NETWORKS
This is one area where DMR is a bit different from D-STAR. Just as in the D-STAR playground, some DMR repeaters are standalone and used for local communication only; however, DMR and D-STAR diverge in how they handle it when repeaters are interconnected.
In D-STAR, repeaters can be linked to reflectors. In DMR, repeaters using static talk groups are linked together in network configurations that are decided by the system administrations, which can’t be changed by individual hams. Some repeaters also allow hams to temporarily subscribe to specified dynamic talk groups.
DMR-MARC and DMRPlus (DMR+)
Initially, there were two main worldwide umbrella networks for amateur radio, DMR-MARC (which years ago was the largest), built on MotoTRBO products, and DMRPlus (DMR+), built on Hytera products. The two networks didn’t interconnect initially. Eventually, the two teams started collaborating on building some interconnectivity, but the use of these two networks hasn’t been growing as much as some of the other newer networks in recent years.
Brandmeister
More recently, a new worldwide network, Brandmeister, was launched. It grew to be the largest amateur radio DMR network in the world. Brandmeister users can key up to (a.k.a., temporarily subscribe to) and use any talk group. It’s also a very friendly network for hotspot users.
On the Brandmeister wiki, they say:
“If you are an amateur radio operator working in digital voice modes like D-Star, DMR, C4FM, APCO25 or others (not all are supported yet!), you do not need to know much about Brandmeister, and it’s very easy to operate on its infrastructure.”– Brandmeister Network Admins
“Brandmeister” is a play (in German) on the words “brand new master server.”
It’s a decentralized, worldwide, community-driven network being developed by an international team:
| Master | Domain | Location | Donations | |
| 3102 | 3102.repeater.net | Dallas, Texas | Donate | |
| 3103 | 3103.repeater.net | San Jose, California | Donate | |
| 3104 | 3104.repeater.net | Chicago, Illinois |
They are joined by teams in countries worldwide that are bringing master servers online, as well as by other teams putting repeaters online. As of July 2019, there are 47 BrandMeister DMR Servers deployed, connecting hundreds of repeaters in more than 43 countries.
As of early 2017, BrandMeister was just a bit more than a year old: development work began in 2014, and the first master servers went online in November of 2015. It’s spreading as fast as a wildfire, which I guess is appropriate since, in German, “Brandmeister” (little “m”) means fire chief.
From the Brandmeister wiki:
BrandMeister is an operating software for master servers participating in a worldwide infrastructure network of amateur radio digital voice systems.… Brandmeister allows you to connect to MOTOROLA DMR-MARC and Hytera DMRplus networks, this means you can operate with other DMR amateur radio operators on both infrastructures at the same time.
Brandmeister has a really nice, robust User Dashboard that includes activity meters and a real-time “last heard” page.
TGIF Network
Another relatively new network is the TGIF network. It has a small but loyal following with hams around the United States. The DMR Tech Net team has a channel that you are welcome to use and utilize. It’s talk group 31268 and there is no 10-minute limit on QSO’s, unlike BrandMeister. You can learn more at: https://tgif.network/help.php
FreeDMR Network
On the 9 November 2020, the birth of a new way of working with DMR was born.
A network name was devised and was called FreeDMR.
FreeDMR is the freedom for Repeater, Gateway Keepers and some Hotspots to have full control, instead of being told what has to go where.
We look forward to a great and bright future.
FreeDMR is a DMR Network for Amateur radio users around the world.
FreeDMR is currently looking for OpenBridge connections to connect to a rapidly growing system.
Open Source is here! FreeDMR – Open networking – Reaching out to the World.
Some features include:
Client configuration sent via Protocol Options line.
Dial-a-TG. All talk groups shifting via Private Call on Slot 2.
Voice idents. The repeater’s or hotspot call-sign is (spoken) every 15 mins.
Enhanced OpenBridge via Improved bridge protocol.
Loop detection & handling on the FreeDMR Network.
More features to come.
https://www.freedmr.uk/index.php/home/
Yaesu System Fusion (YSF)
Our Technology – What is System Fusion?
System Fusion is Yaesu’s implementation of Digital Amateur Radio, utilizing C4FM 4-level FSK Technology to transmit digital voice and data over the Amateur radio bands. In the early 2000’s GMSK emerged in the Amateur radio market as the dominant digital mode, however in 2013 Yaesu introduced “System Fusion” which quickly became the dominating digital format in Amateur radio because of quality, reliability and enhanced performance in a wide range of environments.
Digital Communication modes have gained popularity over the years in the market because of superior performance in environments with interference, noise and other contributing factors that degrade the quality of a standard FM Analog signal. Narrower bandwidth and the need for increased spectrum have led to the development of digital communications technology, which has been widely adopted in the Public safety and private business sectors that use two-way radio technology. Unlike it’s commercial counterpart, System Fusion is an Amateur Friendly Digital Operating mode, straying away from some of the design considerations that make commercial solutions less appealing and more difficult for Amateur Radio Operators, providing a simpler interface and features that meet the demands and needs of the Amateur enthusiast specifically. Below you will find more information on this marvelous new technology, and how it can meet every operators demand and needs for a clear and simple Digital Experience.
http://systemfusion.yaesu.com/what-is-system-fusion/
M17 Project
M17 is a growing community of hardware hackers, software developers, amateur radio operators, and radio enthusiasts. You do not need to be a licensed amateur radio operator to participate with M17, but do be aware that a lot of M17 work is done on licensed amateur radio bands. You can use M17 on ISM bands as well, but experimentation will be limited to the rules and regulations for those bands.
If you are unlicensed, there are a lot of organizations worldwide that can help you get licensed. Information on these organizations is readily available on the Internet.
Join us on one of our chat platforms, and join in on the fun!
Discord: https://discord.gg/G8zGphypf6
Matrix: https://matrix.to/#/#m17-project:matrix.org
IRC: #m17 channel on GeekShed IRC
Open Source Amateur Radio.
We are M17.
M17 is a community of open source developers and radio enthusiasts. We’re building understandable systems in support of the hackers and experimenters’ history of ham radio.
The M17 Protocol is currently supported on several software implementations
Hotspots
WPSD is a next-generation, digital voice software and dashboard suite by W0CHP, which includes native M17 support; as well as programs to update your modem firmware to the latest versions, which support M17.
Alessio IU5BON has a set of scripts to update the ‘classic’ Pi-Star to include M17. Note: This method uses outdated and unmaintained software.
Software Clients / Firmware
mvoice is the original M17 software client to implement the M17 Protocol and Codec 2, written for Linux.
mrefd is the first M17 Protocol reflector software, for linking M17 capable clients across the world
OpenRTX firmware for inexpensive DMR radios includes native support for the M17 Protocol
DroidStar is a multi-platform, multi-protocol DV client software that supports the M17 Protocol out-of-the-box, with no extra hardware or software vocoder needed.
MMDVM Jonathan G4KLX’s Multi Mode Digital Voice Modem firmware for hardware digital voice includes M17 Protocol support.
MMDVM_HS Andy CA6JAU’s MMDVM Hotspot firmware for DV hotspots (commonly used with Pi-Star) includes M17 Protocol support.
M17Client is a pure M17 Protocol implementation for MMDVM modems and hotspots which includes features like slow text during voice TX and GPS location information, written by Jonathan G4KLX for Linux.
Software Defined Radio Platforms
SDR++ includes an M17 decoder built in
OpenWebRX includes support for M17 decoding as an option either at build time, or in the software image
TIME SLOTS
When there are so many puzzle pieces that need to be fitted together to set up a DMR radio successfully, it’s challenging to figure out where to begin.
DMR uses Time Division Multiple Access (TDMA) to generate its signal instead of the Frequency Division Multiple Access (FDMA). Specifically, DMR uses 2-slot TDMA (the slots are numbered 1 and 2, or TS1 and TS2).
What this means is that calls on two different channels can share the same frequency simultaneously. Each call is sliced up into chunks of a few milliseconds, and the slices from the two calls are interleaved on the signal. This happens so fast that we hear what we perceive of as a continuous transmission even though it’s coming in chunks, looking like this:
This also means that when you program a DMR channel, you must specify both the frequency and the time slot, so that your radio and the repeater can encode and decode which chunks on the signal belong to the channel you’re using.
COLOR CODES
Another fundamental piece of the puzzle is color codes (CC). Think of the as the digital version of a PL tone like you find on analog repeaters. When you want to use a DMR repeater, you need to program in the appropriate color code to open it up and have the repeater respond that it’s hearing your transmission. There are 16 color codes, 0 – 15. Why are they called color codes? Nigel, G8IFF educated us on the answer:
“[I]n the early days of DMR being a Motorola commercial system, the radio programming was done by Motorola who sold you a “plug” containing diodes that you plugged into a socket on the radio’s circuit board. No user programming in those days. The color code was so called because it was indicated by a colored dot printed on the code plug you were supplied with.” Nigel, G8IFF
Just as with analog radio CTCSS tones, you need to get the appropriate color codes from the organization operating the repeater in order to be able to use the repeater. When you program a DMR channel, in addition to the frequency and the time slot, you must specify the color code; otherwise, you won’t be able to access the repeater.
The magic formula to accessing a DMR repeater…
Frequency + Time Slot + Color Code
Let’s take a look at an example of a local Lansing, Michigan DMR repeater.
Frequency: 442.0875 (+5 MHz)
Color code: 1
Time slot: 1
The above programming will get you onto the wide-area MI State time slot 1 of the KB8SXK repeater located on top of the old McLaren Hospital on Greenlawn Avenue.. It’s a part of the Mi-5 system.
Frequency: 444.7875 (+5 MHz)
Color code: 2
Time slot: 2
The above programming will get you onto the KB8SXK time slot 2 of the Lansing repeater located on top of the old McLaren Hospital on Greenlawn Avenue. This repeater is also a part of the Mi-5 system.
TALKGROUPS
Finally … let’s talk about talk groups!
Of course, the whole point of getting onto a DMR repeater is to talk to other hams, and you do that by visiting a talk group, which enables one-to-many communication, sort of like a conference call or a chat room. Anything transmitted to a talk group is transmitted to everyone listening to (linked to) that talk group.
There are worldwide, nationwide, regional, statewide, area, and local talk groups, as well as language-based talk groups. For example, on Brandmeister:
- Talk group 91 is Worldwide
- 93 is North America
- 3100 is U.S. Nationwide
Note: 3100 is an example of a talk group that is bridged across networks; it is U.S. Nationwide on the DMR-MARC, DMR+, and Brandmeister networks. - 3126 is U.S. State of Michigan
- 3169 is U.S. Midwest Region
- 9 is for using local communications on a single repeater
- 2 is used when repeater owners decide to link multiple repeaters in a region together
In addition, there are the TAC (Talk Around Channel) channels (U.S.: 310 – 319; worldwide: 901 – 903). TAC 310, 311, and 312 are bridged between different networks, and Brandmeister is a guest on these channels. Hams that want to have longer chats in order not to tie up main channels that are more widely shared can use the TAC channels.
But what about the difference between static talk groups and dynamic talk groups?
Talk groups are either static (always activated) or dynamic (user-activated). When you activate a dynamic talk group on a repeater’s time slot by keying up, it typically remains activated while there are transmissions on it, then drops from the repeater after some period of inactivity, for example, after 10 or 15 minutes. You don’t need to manually unlink from a talk group.
When you’re using a simplex hotspot on the Brandmeister network, there also are auto-static talk groups that you can setup on your hotspot. For more info, see the article Brandmeister dynamic, static, and auto-static talkgroups.
On many repeaters in Michigan and across the country, the talk groups you can use on a given time slot are specified by the repeater administrator, including any dynamic talk groups you want to use. Please see MNDMR talk groups to understand how most MNDMR repeaters are programmed and what talk groups they allow on TS1/TS2. If you want the freedom to use any talk group you’d like, you might want to invest in a Pi-Star hotspot.
The Pi-Star website also hosts a current and complete Brandmeister Talk group List, including descriptions and a link to the Brandmeister Hoseline page, where you can listen to activity.
Wondering what hoseline is? https://hose.brandmeister.network/ is live audio feed database where you can monitor any talk group on Brandmeister using your computer, tablet or phone but you’re unable to talk. You can only listen.
ZONES
Zones are an organizational tool, like file folders, for the channels in your DMR radio; in other words, a zone is a group of channels.
The channel selector on many DMR radios lets you choose from 16 (or more) channels. In order to get past that limitation, you can use zones. For example, a typical DMR radio that could handle 64 zones capable of storing 16 channels each, for a total capacity of 1,024 channels.
You can organize your zones however you want, for example, you might want one or more “Home” zones for channels that correspond to your favorite talk groups that you can reach via the repeaters that are within range of your home. You might want a “Commute” zone that corresponds to the talkgroups you most often use via the repeaters that are in range as you drive to and from work. If you use a hotspot, you might want some “Hotspot” zones for the talkgroups you key up via your hotspot. You might want some other zones that correspond to the groups of talk groups your club uses, or to nets you frequently participate in. Some people set up zones based on repeater locations.
It’s pretty easy to use zones: you create a zone, name it, and then add channels to it. Optionally, you can change the order of the channels within the zone.
SIMPLEX FREQUENCIES
Just as you can use analog transceivers in FM mode, you can use DMR-capable transceivers to talk directly from radio-to-radio simplex. These are commonly used North America DMR simplex frequencies and are recommended for all DMR users in the United States to have programmed:
Admit criteria: Always or Channel Free
Time slot: 1
Color code: 1
Talkgroup ID: 99
UHF simplex channels:
- 441.0000 MHz
- 446.5000 MHz
- 446.0750 MHz
- 433.4500 MHz
VHF simplex channels:
- 145.7900 MHz
- 145.5100 MHz
CODEPLUGS
“Codeplug” is a common name used for a radio configuration file that sets the frequencies, color codes, timeslots and talk groups into channels which are organized into zones. Code plugs can be shared to minimize the time and errors to configure a radio. Michigan-focused code plugs for popular radios are available here.
DMR NETS
A good resource for finding DMR nets across the United States is the Ham Radio DMR Nets Telegram group. It has a quite comprehensive list of active DMR nets. Each net is displayed an hour before it goes live, making it easy to find out what’s currently on the air: https://t.me/HamRadioDMRNets
DMR Nets in Michigan:
- Saturday 7:00pm-7:15pm Arrow DMR Net on BrandMeister TG-3126
- Saturday 7:30pm-8:00pm DMR Trivia Net on TGIF talk group 31268
- Sunday 6:30pm-7:00pm UP (Upper Peninsula) Net on BrandMeister TG-31268
- Monday 7:30pm-8:30pm DMR Tech Net on BrandMeister TG-3126
- Monday 8:30pm-9:15pm Michigan One DMR Net on BrandMeister TG-3126
Michigan DMR Talk Groups:
TG-3126 Michigan statewide
TG-31260 Michigan WX/ARES/EmComm
TG-31261 Mi-5 Statewide 1
TG-31262 Mi-5 Statewide 2
TG-31263 Mi-5 Event 1
TG-31364 Michigan TAC (Talk Around Channel)
TG-31265 Mi-5 Event 3
TG-31267 West Michigan Talk Group
TG-31268 Upper Peninsula Talk Group
TG-31269 West Michigan Technical Group
DMR Resources:
https://www.michiganonedmr.net/ to find Michigan Brandmeister repeaters & it’s a good DMR resource
https://dmrtechnet.net/ a good DMR resource
https://radioid.net/ to request a free Digital Radio ID & update your digital contacts list
https://brandmeister.network/ good resource guide to Brandmeister repeaters
https://support.bridgecomsystems.com/product-support good support page for Anytone radios
https://www.repeaterbook.com/ to find Michigan DMR repeaters (listed later in this document)
https://www.radioreference.com/ to find Michigan radio frequencies (Police, Fire. Air, etc)
https://www.youtube.com/@BridgeComSystemsInc
https://www.youtube.com/@HamRadio2
https://www.youtube.com/@HamRadioCrashCourse
https://www.youtube.com/@ARRLHQ
https://www.youtube.com/@HR4NT
https://www.youtube.com/watch?v=ts2nkCDIS4s&list=PL0R9jy9LZw_2Je-1Td9Xb2S8-Vl_bFTGG
This book is a guide to Digital Mobile Radio (DMR). It will help you to become familiar with the complex terminology used by the DMR crowd, purchase and program a DMR radio, and make your first few calls. It also includes sections on how to configure and use a DMR hotspot, using DMR repeaters, and talk groups. The book takes a practical approach, providing the information you need to get started with this exciting digital voice technology. Before you know it, you will be able to talk with amateur radio operators all over the world.
The Parrot TG channel (TG9990) allows you to talk to yourself to verify connectivity and strength with a hotspot/repeater, and every TG that we connect to, we MUST disconnect-from using the SKY TG Disc channel (TG4000).
Tom N8TJ:
Novice 1977 as WD8NPM.
Currently most active on: DMR 3126 Brandmeister, 80m, 40m 20m CW.
Other interests: motorcycles and northern MI.
tom@dmrtechnet.net
Stan WB8QJZ:
I was licensed as a Novice in 1973 as WN8QJZ. I upgraded to Technician C and then to Amateur General Class. Primary interests include portable HF QRP operation and VHF/UHF experimentation including Slow Scan Television reception from the International Space Station . I hold a Commercial General Radio Telephone License. I retired from Michigan Technological University as a Senior Telecommunications Engineer and was the operator and chief engineer for the university’s Ku Band Satellite Earth Station. stan@dmrtechnet.net
Steve KC8WXM:
Was in the U.S. Army 2nd of the 4th Cav. Crew chief for OH-58C Helicopters. Was sent to Saudi/Iraq during Desert Shield, Desert Storm.
Hobbies: Camping, Hiking, Hapkido, Amateur Radio, and playing the bagpipes!
Past Commander of American Legion Post 194 in Petoskey and currently Quartermaster of the Petoskey VFW.
steve@dmrtechnet.net
Dana KC0MYP:
In 1977, I passed the FCC 3rd Class license with broadcast endorsement to work at WVIC 94.9-FM/730-AM. After graduating from Michigan State University, I moved to Colorado and worked at Radio Shack for 19 years. In 2002 I earned my Technician class license and upgraded to General in April, 2022. Technology is great–when it works! Currently using three AnyTone 878 handhelds and two AnyTone 578 mobile radios with BT-01 Bluetooth mics. I’m most active on TGIF Talk Group 31268 & Brandmeister DMR Talk Group 3126 Statewide Michigan. dana@dmrtechnet.net
Brian KE8NJT:
I received my Technician license in 2019, my General a year later and am currently studying for my Extra. I started fooling with end feed antennas in Viet Nam. They really increased the range of a PRC77, I’m retired from our Sheriff Department where radios were a way of life. In early 2023 I became interested in DMR and now have a base station and hand held DMR radios. 73 de KE8NJT. brian@dmrtechnet.net
Brad KE8WNV:
I spent 9 years in the Army as an Ammunition Supply specialist. I was cross Trained as a Fuel Handler, and RTO for my company. We worked Primarily with the Apache Longbow Attack Helicopter. As the RTO I was in charge of all our radios and ensuring secured communications were loaded. I currently work as a Desktop Support Specialist and enjoy working with technology. I am new to Ham Radio, having my license since February 15th, 2024. Having a technical background made DMR easy to pick up and understand. I am no expert in anything but do understand the concepts quite well. brad@dmrtechnet.net
Topics for future DMR Tech Nets:
- Go back over the Digimon feature to explain what it is, how and why to use it.
- Hot Keys. What are they, why use them, and how to set them up.
- DMR tips. Like what Steve KC8WXM mentioned to better (and faster) utilize DMR features.
- Adding or changing DMR channels via keypad programming.
- How to update your DMR digital contacts via https://radioid.net/
- Asking check-ins what they know now that they didn’t know when they started with DMR that would be helpful to other beginners (Elmering)
- A timeline to get started of essential things to do with DMR and why.
- Which DMR radio do you use the most & why?
- Proper DMR practices & procedures to use on-air
- DMR text messaging
- Advanced features of the Anytone 878 handheld and 578 mobile radio
- Going over the different DMR networks (Brandmeister, TGIF, M17, DMR+, YSF, etc)
- Useful radio accessories to use with your DMR equipment
- Unique names used instead of the amateur radio alpha codes
- Antennas for handheld, mobile, and home radios
- Logging software
- QSL cards Do you send them out?
- Repeaters, hotspots, or both? Which do you use and why?
- WPSD hotspot dashboard
- APRS & GPS
- Custom call signs
- What are your predictions for the DMR world in 2024?
- What networks and talk groups do you use, and why?
- What features do you wish your DMR radio had?