Any hams here using DMR (digital mobile radio) units?

robgendreau

Explorer
I'm wondering about using DMR, especially out in the boonies. I've seen one demo'd and the quality is phone-like. But it seems it would be meh to use out in wilder places. But maybe I'm missing something; I'm pretty unfamiliar with it.
 

lugueto

Adventurer
There is tons of information about the advantages and disadvantages of digital voice modes, DMR vs other digital voice modes and what not. I personally haven't tried it because support in our country is very limited, but I have read a lot about it.

For backcountry use I believe you can use simplex, and audio quality indeed is better. But longer range may suffer. I'm sure you're aware that, indeed you get a clearer signal with lower signal strength, but when it goes beyond a threshold it goes completely quiet.

I'd much rather have a noisy low signal than a clear signal up until a certain point. I'm personally sticking to analog FM for off-the-grid communications.
 
I use dstar in remote places. It's nice as you don't have to ID by voice (callsign is in the data channel), and the signal never has any static. The downside is that nobody outside your own group can hear you as the equipment is rare even among ham operators.

DMR can be used simplex, but it won't auto ID, and setting it up is more complicated. DMR is arguably more prevalent then dstar since the radios are cheaper. Neither is as common as fm though.

I wouldn't try a simplex "call for help" on either one of these.

If you want to geek out then use Dstar on 6 meters on the trail. The digital signal does a good job cutting through the noise floor, and the frequency is low enough that it gets out really far in the hills.
 

DaveInDenver

Middle Income Semi-Redneck
I have DMR radios but away from repeaters I'd agree that their usefulness is limited. In general digital is not the best choice for fringe coverage since you get little indication you're at low signal strength if you're not watching your RSSI. Most digital radios will use RSSI to determine when to start looking for a stronger repeater and it's a settable threshold in CPS as the point when to start roaming usually.

The range where the perceived audio quality is better will be relatively small. IOW, when you get good signal strength both analog FM and digital will sound fine (ignoring for the moment bandwidth and baseline quality, since DMR does sound good). When you get to a mid-range point where analog is no longer full quieting but still has a high signal-to-noise the digital radio will not have background static, so will seem to be better. And it is. Up until you hit the point where your SNR starts impacting bit error rate. That's when you can usually still understand voices in the noise with analog but get the robot sounding voices with digital modes that often just unintelligible.

That situation is tough in the backcountry because it's all or nothing and you often go from one extreme to the other due to terrain. That's why digital has taken some time to be adopted by firefighters in particular, who get themselves into places where structures cause SNR issues.

The good thing about DMR radios is they are usually very high quality and are therefore also typically very good analog radios, too. Mine are Vertex and Motorola, built like bricks with outstanding audio TX and RX even on FM. So you have a solid fall back.
 

DaveInDenver

Middle Income Semi-Redneck
Dave, any analog/digital radios you'd recommend??
I'm a fan of the Vertex Standard VXD-720, which is the guts of the XPR series Motorola in a Vertex case. Some features, such as roaming, are not present (they are firmware disabled) but the basic functions are there for DMR. The main reason for my recommendation is Vertex doesn't charge for software, so it's easier to get them going.
 

DaveInDenver

Middle Income Semi-Redneck
Something else occurred to me about DMR radios in the backcountry. Being that many are repurposed commercial land mobile rigs they often lack front panel programming. That's handy and sometimes could be considered a critical feature. There are options that do, the Connect Systems radios can be programmed in the field usually without a computer, for example.
 

wirenut

Adventurer
I recently purchased a Yaesu FT1X Fusion radio. I can see it having some good features for use talking between vehicles on the trail. Using the built in GPS the radio will transmit position, distance, and speed information along with your audio. This makes it very easy to keep track of how far you are form the other station(s). The audio is very clear. I was amazed the difference it made when switching from an S 3 to 5 analog signal to the digital format. All the hiss totally disappeared. Yaesu makes both hand held and mobile rigs for the Fusion system. The FT1 and FT2 hand helds along with the FTM-400 mobile have built in APRS too. You can use this to keep track of position as well as send text messages between radios.
 

DaveInDenver

Middle Income Semi-Redneck
At one time the installed base for Fusion was the problem but I guess it's really leveled out with DMR. The radios do have some compelling features.
 

uli2000

Adventurer
Looking in online Repeater directly in a two state area fusion repeaters outnumber dstar and dmr.

There's a lot of fusion repeaters out there, the reason being Yaesu subsidised the crap out of them to get them installed. But the bulk of them rarely, if ever, have any Fusion traffic. Almost all of them are set up in hybrid mode which allows both fusion and analog fm. Analog users cant talk to fusion users so the bulk of them get used for analog fm only. The first gen of the DR-1 isn't upgradeable to Yaesu's Wires-X internet linking, and the DR-1X requires an upgrade, which isnt avalible yet. There is another linking scheme that will bring some cross protocol talkgroups with dmr and dstar users, but I cant say I know much about it.
 

Sandexplorer

New member
A dual band MD2017 will give you a lot of options around town and out in the bush. When out of range of a repeater you can always use a Shark RF Openspot for accessing the Brandmeister network.
Cheers
 
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