DMR Question

[Volfirefighter]

Is there a relatively inexpensive handheld on the market capable of receiving a DMR Motorola Capacity Plus (TRBO)? Note that I would disable transmission; it is not my intent to transmit. I currently monitor this site on my SDS200 but wish to repurpose this scanner for a P25 simulcast system.

 

[rdlinn]

Anytone makes great little radios

 

[RaleighGuy]

TYT MD-380 - DMR/Moto TRBO Ham Radio under $100

 

[sallen07]

Is there a relatively inexpensive handheld on the market capable of receiving a DMR Motorola Capacity Plus (TRBO)?

There are a number of DMR HTs on the market, including the ones mentioned. Couple more are the Radioddity GD-77 and BTECH DMR-6X2.

But ... none of those will trunk-track a CAP+ system. If you are content to just program in all the voice frequencies and scan them, you can do that. You just won't be able to follow a particular talkgroup.

If you want to trunk-track the system then a Uniden BCD325P2 with DMR upgrade would do the trick. There are current (and discontinued) Whistler scanners that can 'hear' DMR too, but they also just scan the voice channels.

 

[Whiskey3JMC]

Anytone makes great little radios

TYT MD-380 - DMR/Moto TRBO Ham Radio under $100

These don't track MOTOTRBO trunked systems like CAP+, CON+, etc like the OP requested. Yes they can receive the voice channels if you program them conventionally but with CAP+ the "rest channel" may change on occasion and you'll hear nothing but data bursts every 2 seconds if you stay on that frequency...

 

[rr60]

Ummmm. Anyone know if they RX /\/\ RAS protected system?

 

[west-pac]

Ummmm. Anyone know if they RX /\/\ RAS protected system?

I had a run in with an RAS freq a couple years ago. My DMR radios would not receive it, but my SDR dongle would.

I'm stretching my brain back to that time period, but I believe it was explained as: RAS adds some extra 1's or 0's to be decoded, and a radio without RAS capability disregards the whole transmission because that transmission doesn't fit the radios definition of a legit "DMR" transmission because of the extra 1's or 0's.

 

[racingfan360]

Ummmm. Anyone know if they RX /\/\ RAS protected system?

It won't. Most digital scanners and SDR/software solutions will, but for a transceiver it needs to be not only a Moto DMR unit and the correct RAS authentication key.

 

[slicerwizard]

I'm stretching my brain back to that time period, but I believe it was explained as: RAS adds some extra 1's or 0's to be decoded, and a radio without RAS capability disregards the whole transmission because that transmission doesn't fit the radios definition of a legit "DMR" transmission because of the extra 1's or 0's.

There are no extra bits to be decoded. RAS changes the checksum values on link control messages, which cause receivers with the wrong RAS key (or no RAS key) to discard those messages as damaged/garbage. Without link control decoding, radios don't know who's talking, hence no way to know which transmissions to unmute on.

 

[west-pac]

There are no extra bits to be decoded. RAS changes the checksum values on link control messages, which cause receivers with the wrong RAS key (or no RAS key) to discard those messages as damaged/garbage. Without link control decoding, radios don't know who's talking, hence no way to know which transmissions to unmute on.

I think we essentially said the same thing, differently.

 

[PACNWDude]

There are no extra bits to be decoded. RAS changes the checksum values on link control messages, which cause receivers with the wrong RAS key (or no RAS key) to discard those messages as damaged/garbage. Without link control decoding, radios don't know who's talking, hence no way to know which transmissions to unmute on.

I always set my RAS key for DMR Trbo systems to something besides default, and not to all zero's like some of my less detailed co-workers. Currently using XPR5550e mobiles and XPR7550e handhelds across the country at many sites. Great radios.

 

[slicerwizard]

I think we essentially said the same thing, differently.

I don't think so.

 

[west-pac]

I don't think so.

I don't care.

 

[slicerwizard]

Nor do I.

 

[Volfirefighter]

I checked and the users on this DMR Motorola Capacity Plus (TRBO) system use Motorola XPR 6350's. These are discontinued and can be had on ebay for $100 or less. Can these be programmed to receive only or do they need to "affiliate" with the trunked system like a radio on a P25 system would?

 

[n3wrx]

I checked and the users on this DMR Motorola Capacity Plus (TRBO) system use Motorola XPR 6350's. These are discontinued and can be had on ebay for $100 or less. Can these be programmed to receive only or do they need to "affiliate" with the trunked system like a radio on a P25 system would?

That's an interesting question, and I don't have a direct answer - but I would point out as a note of encouragement that P25 radios can be programmed to track a trunked system conventionally (using NAC codes IICR correctly). I've done it with great success for P25 systems using an older Moto radio with a conventional scan, and it works amazingly well. I wouldn't be shocked if an analogous solution might work for DMR trunked systems - and for under $100, I'd venture it would be worth a shot.

 

[slicerwizard]

I checked and the users on this DMR Motorola Capacity Plus (TRBO) system use Motorola XPR 6350's. These are discontinued and can be had on ebay for $100 or less. Can these be programmed to receive only or do they need to "affiliate" with the trunked system like a radio on a P25 system would?

You would need to determine if the system is using RAS.

RAS = no monitoring with a DMR radio unless you know the RAS key.

 

[racingfan360]

I'm sure others will correct me as necessary, but as a general rule of thumb:
1. A DMR-capable scanner or SDR with DSD+ will allow you to listen to a non-encrypted DMR system, whether it be trunked or conventional
2. DSD+ and some of those scanners will trunk track a Motorola system. No option will properly trunk track an XPT system.
3. A scanner or DSD+ ignores RAS. But only DSD+ will tell you if RAS is being used.
4. Any DMR transceiver will allow you to passively listen to a DMR system, but (I think) only a MotoTRBO transceiver will trunk track a Motorola one, and only a Hytera transceiver will trunk track an XPT one.
5. No transceiver of any make will enable you to listen to a RAS enabled system, unless you have a MotoTRBO transceiver and the right RAS key.
6. You'll be out of luck completely if it's an encrypted system (A Motorola Basic Privacy system key could be guessed through bute force quite quickly, then the key added to a MotoTRBO transceiver, but it would still be illegal in most countries anyway).
7. DSD+ is still the easiest route in to tell you exactly what the system is and what it is using by way of configuration, privacy and integrity

 

[MStep]

You would need to determine if the system is using RAS.

RAS = no monitoring with a DMR radio unless you know the RAS key.

But even if you know the RAS key, as far as I know, there are no conventional scanners that have provisions to accommodate entry of that key. I imagine that you would need to have a dedicated DMR radio that allowed for key entry.

 

[K2NEC]

But even if you know the RAS key, as far as I know, there are no conventional scanners that have provisions to accommodate entry of that key. I imagine that you would need to have a dedicated DMR radio that allowed for key entry.

Most DMR scanners ignore the headers associated with RAS