DMR – Digital Mobile Radio

When the internet fails…

DMR has taken off in our local ham club, and around the world. If you just want someone to talk to, there is always someone out there, somewhere around the world. If this is what you’re in ham radio for, then you’ve got it made.

In these days of sunspot cycle low, it’s getting harder and harder to make contacts using traditional ham radios. I think many people are turning to DMR for that reason alone. I get that. They say that “In DMR the bands are always open.” since whenever the bands are closed, or there are poor propagation conditions, you don’t need a huge antenna and a thousand watts to have a QSO. You can rely on the internet to do the heavy lifting for you.

I’m known for giving DMR radio quite a hard time, calling it (among other things) the Skype of ham radio, and it’s mainly because for me, DMR removes the number one reason for excitement from ham radio – the “wow” factor associated with bouncing a signal off the atmosphere and talking to someone on the other side of the world.

When I key up and talk to someone in Europe or South America (or even here in the USA, many states away) using good old normal ham radio, it’s exciting, I get a kick out of it, and it’s worth logging. I get none of this from talking to anyone anywhere on DMR, and see no point in logging a DMR contact. That excitement is gone.

Putting that blah feeling aside, I do concede to the fact that this is another aspect of ham radio, and it’s great to see people building their own DMR hotspots using cellular devices and whatnot.

Does DMR work? Yes. It works pretty well for what it is. I wonder though, if there is a general concern about a commercial digital radio system making its way into ham radio. Is this the first time such a thing has happened?

When all else fails, the long standing maxim of ham radio does not apply when it comes to DMR, and I really can’t grasp the excitement when it comes to DMR. If this was 1992 and the internet was in its infancy, maybe I would be excited about it, just as it was exciting back then to chat with someone on the other side of the world via IRC, or a BBS, or email, but expecting me to be excited about talking to someone on the other side of the world using a DMR radio in 2018 is tantamount to expecting me to be excited about a light coming on when I flip the switch on the wall.

I guess that’s enough misery for one day. I’ll go turn my DMR radio on 😀

 

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3 Comments:

  1. Things I think are cool about DMR: Ability to put usable voice in a 6.25-kHz channel. Decision to make it 2-slot TDMA (total bandwidth is 12.5 kHz) which means you literally get two repeaters for the price of one not to mention reduced duty-cycle on battery-powered portable radios.

    Things I don’t think are cool about DMR: Use of proprietary vocoder which makes it legally impossible to home-brew a DMR-compatible radio (same is true of D-STAR, though a different vocoder within a different protocol). Use of non-amateur means to network repeaters. Use of old Motorola term “code plug” in place of term configuration.

    • Code plug… I know, man. The beatings will continue until that phrase disappears. 🙂

      It’s certified as a FCC part 90 radio, so goes through the part 90 test procedures. As far as the emission goes, the actual 99% Occupied BW of the GD-77 is around 9.5 kHz, which isn’t bad at all. Transmit switching transients are pretty good too.
      Reference: https://fccid.io/2AN62-GD77/Test-Report/Test-Report-3672001.iframe

      The technology is cool, but like I said above, there’s no wow-factor for me. Not when I carry a cell phone.

      • Right. You hit the nail on the head – Skype. No different … past the repeater. The RF part is pretty cool. And if we could link up using amateur radio means (and Mark et al have discussed/are discussing that), then it gets more wow-y for me.

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