On Sunday, June 17, 2018, WSSM members set out on a coordinated mountain topping expedition in order to learn more about the range limits of DMR simplex. The longest distance contact achieved was between Mt. Equinox, VT and Saint-Jean-Sur-Richelieu, QC – a distance of: 151.13 mi / 243.22 km (UHF), and the second longest was between Mt. Greylock, MA and Mt. Washington, NH – a distance of: 145.56 mi / 234.25 km (both VHF and UHF).
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by Tim Watson, KB1HNZ
There is no question that DMR technology for hams has moved past the early-adopter phase and is now well into the mass adoption phase. The combination of an open source protocol and the availability of inexpensive, mass-produced Chinese DMR radios (in some cases for as low as $109 with a color display and free programming software), has made this possible. In addition to inexpensive new radios, there are a number of used, first generation Motorola and Hytera DMR radios for sale in flea markets. These radios perform just as well as the current models, but have less memory.
D-STAR, Fusion, and to a lesser extent NXDN, are all established digital voice modes, and are not going away anytime soon, but in many areas they are not experiencing any meaningful growth when compared to DMR. This is especially true for the Northeast. In New England alone, there are close to 80 active DMR repeaters, and this number is growing every day.
Because of Yaesu offering repeaters for $500 for a period of time, there were a few installed in the area (in most cases replacing existing FM repeaters), but from my experience, it’s been extremely rare to find anyone using C4FM, and in some cases these repeaters are operating in just FM mode, so the digital part isn’t even an option. It’s hard to say exactly why Fusion or D-STAR hasn’t taken off, (last time I checked there were only 3 D-STAR repeaters in Maine), but it probably has a lot to do with price. D-STAR and Fusion radios aren’t cheap, and without some assurance that there will be a repeater within range to use them on, it’s hard to justify the cost.
Unlike the other modes, there is also something unforced and organic about DMR. Its cutting edge, and yet, it still feels like ham radio. A lot of members of our club were early adopters, and have also explored uses for DMR in both the EmComm environment, and for SKYWARN. For SKYWARN, especially, the DMR-MARC network has been an extremely useful tool to gather weather reports from areas that are outside the range of typical FM repeaters.
For more information about DMR, click here to check out our DMR Intro web page.
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