DMR Radios: Its giving radio-nerd vibes

Greg Heffner August 25, 2024

Nerd alert! Playing radio has always been fun to me. From the game Cops and Robbers to pretending to be a truck driver on a CB radio, I have always had a good laugh on the radio waves. "Uhhhhhhh, breaker breaker, one nine." hahahaha Anyone know what one nine means?

When I was a kid, my interactions with radios were limited to the FRS (Family Radio Service) channels 1-22. I used local radios I got from the store to talk to friends in the neighborhood or friends at summer camp. If my friends weren’t on channel 1 and didn’t respond to the 15 call alarms I sent while running around, the next step was to switch to channel 2 and repeat! Those pre-cellphone days, what a time to be alive. I didnt have much other experience with radios until I got into the US Army and joined the Signal Corps. I was privileged enough to go to school and learn about radio signals, encryption keys, and network switching systems. This meant I could play with Air Defense radios and antennas that has signal propagation that covered entire Countries. We used radios and radars to send digital signals over the air to shoot missiles. Yep, I am sigma radio-nerd. My aura was intoxicating. I was the radio rizzler. No cap. Fast forward to today and being a civilian again, I no longer get to play with encrypted radio signals BUT I do get to play with amateur radio known as HAM radio and its Digital Multiplex Radio (DMR) servers. Just like other federally regulated services the Federal Communications Commission (FCC) requires a license before you can operate these radios. One Saturday morning I decided I wanted to get my license and get on the air. I hit the books and binged studied all morning from 4am until 1pm with practice tests, videos, and walkthroughs eventually passing the online proctored exam later that day. After a couple weeks I received my callsign that was assigned and I was able to transmit! Thank you HAM Radio Prep

Setup

Digital Radio uses the same radio signals as the radios you can get from the stores but one of the differences is that these radios connect to servers and send the traffic over the internet not just in your local area. In order to be able to do this there are a few things you need.

• Repeaters are devices that are connected to the internet and are used to transmit your radio signal to other radios. Most areas have towers with digital antennas installed right next to the analog antennas. These towers are used for FM and AM radio or police, fire, and commercial entities use these towers for their emergency communications. As I travel around town I can connect my radio to the nearest tower with the highest signal.



• PiStar Nodes- If you find yourself as I do in an area where you dont quite have good repeater signal coverage or if you use your radio indoors you may not be able to use your radio very well due to signal loss. Luckily for digital radios you can connect to a Raspberry Pi with an application called PiStar. As long as the Raspberry Pi is connected to the internet and your radio is on the same channel, the PiStar application will transmit your traffic for you just as if it was a repeater on an antenna outdoors.



• Brandmeister- This is where all the magic happens. The Brandmeister server network is the group of devices connected together that create virtual chat rooms of radio groups called TalkGroups. These talkgroups are shared across the internet and as long as your local node is connected to the room you can send traffic to it. Think of this like a radio version of current day slack. You cant send a message or see whos talking in some channels until you join. These talkgroups are connected to each repeater or pistar device to create the connection to your radio. This is how I can be in Florida and talk to a person in Bangladesh. TalkGroup Listings



• The radio- I use an Anytone878 radio and the reason why is that I can monitor two channels at once. I like to monitor a digital channel for my local area called First Coast DMR which is Brandmeister 31121 and then also an analogue channel called Statewide Amateur Radio Network (SARNET) the State has broadcasting. This radio can hold 500k contacts which display when broadcasting allowing you to know who youre talking to and where they are from.

When I turn on my radio it is auto-configured as described above. With just a twist of a dial my radio is connected to a network of devices literally across the World. So much further than any tropo shot I ever saw. Take that US Army!!! When I connect to WorldWide or North America Channels it gets so fun. There are conversations about weather, local events, disasters, current events everything. I particularly like to check in first thing in the morning for a show called The Morning Brew on First Coast DMR between 6am and 8am EST and in the evening to the Jax AllStar Hub where AB4KK has a connection all across the southeast USA and Tech Nets he hosts weekly on Sunday nights at 8:45PM EST. I wouldnt be where I am today with my radios without the help from KM4CTB and AB4KK. Thank you both so much for all the help and coaching. They helped me so many times with configs and radio checks late night and early mornings.

Please check out HAM radios in your local area and join the community, its really fun. As KM4CTB would say, "Stay Radio Active."

More Learning

If you are ever interested in listening to any HAM nets or live radio check out these links:

Brandmeister Last Heard
Filter By World-wide and you should see something saying destination (91) click the speaker and then a new window will open. Find the square where (91) is and click it to start listening. Ive talked to people from Australia to Bangladesh from my living room.


Hurricane Watch Net
This channel is used for communications when Hurricanes are impacting anywhere in the US. People will join and share information and updates with emergency services and friends and families. I use the 14.325MHz channel primarily.

East Coast Reflector This is a HUGE community and covers such a large geographical area of the US. Check out all the connected nodes East Coast HUB1.Check out their live nets here.

Video Links:
What is HAM Radio
What is DMR (Digital Mobile Radio) Aishi
Empowering Women in HAM Radio