RAS , CAP plus or Trunk DMR Monitoring

[blackbelter]

Is there a budget DMR radio to monitor ( Only) this station managed by Brookfield Properties Group
Boca Raton Mizner Park FL Operation.
463.875 WQDX857 either DMR TRunk, CAP Plus, DMR Tier 3 or perhaps RAS enabled.
I realize a Scanner can, however I am looking for a small DMR radio to use. .
Thanks,

 

[kayn1n32008]

Is there a budget DMR radio to monitor ( Only) this station managed by Brookfield Properties Group
Boca Raton Mizner Park FL Operation.
463.875 WQDX857 either DMR TRunk, CAP Plus, DMR Tier 3 or perhaps RAS enabled.
I realize a Scanner can, however I am looking for a small DMR radio to use. .
Thanks,

If it’s using RAS you are out of luck. Period.

If it’s capacity plus, or connect plus you would need a Motorola TRBO radio, appropriately programmed.


Sent from my iPhone using Tapatalk

 

[slicerwizard]

Why would a single frequency system need a MotoTRBO radio?

 

[N8IAA]

Is there a budget DMR radio to monitor ( Only) this station managed by Brookfield Properties Group
Boca Raton Mizner Park FL Operation.
463.875 WQDX857 either DMR TRunk, CAP Plus, DMR Tier 3 or perhaps RAS enabled.
I realize a Scanner can, however I am looking for a small DMR radio to use. .
Thanks,

Are you sure that's DMR? Under that license, it is FM analog.

 

[blackbelter]

Yes It is , just not updated.

 

[blackbelter]

I also understood that some 3rd part FW would enable the inexpensive DMR radios to receive in promiscuous mode and pass on the audio.

 

[Ubbe]

No, not RAS. Promiscuos mode only lets you monitor all TG and private calls but does nothing for RAS which is a totally different thing.

/Ubbe

 

[blackbelter]

Thanks,

 

[RRR]

"RAS" basically adds/distorts the "headers" in the digital stream, so actual MotoTrbo radios can't receive them (or mainly, transmit on them), without a decode key.

Why would this be an issue with a scanner or other maker's radio? I was under the impression they basically ignored the headers?

 

[slicerwizard]

It's an issue because RAS modifies the packet checksum fields and all receiving devices use those checksums to verify that data is being correctly decoded. Ignoring voice headers would mean having no idea what talkgroup one was receiving.

 

[IAmSixNine]

There is a mall not far from me that uses RAS / Cap Plus and my BCD436 picks it up just fine.
My XPR7550 and Hytera radio wont pass any audio.
So for me using a scanner RAS is not an issue.

 

[RadioGuy7268]

My understanding is that some of the cheaper offshore DMR radios would just ignore the RAS header & could still recover DMR audio from the bitstream. I haven't played around with it myself to know for sure.

Even in promiscuous mode, they're not going to play along with Tier 3 level trunking. You can scan individual frequencies/repeaters, but you're not going to follow trunked talkgroups.

I'd be curious to see if the FCC is taking any enforcement action against people who put up a DMR trunked system & never bother to modify the License from analog conventional.

 

[Ubbe]

All data transmitted thru air needs error correction and all radiosystems uses it. You can ignore RAS but then you cannot do error checking and error correction so even with a practicly noise free signal there will be errors in the data stream that cannot be detected and will give false results, like the wrong TG number are decoded. I don't know how scanners cope with it, if they decode 4-5 dataframes with what should be the same info and then selects to use the data from two frames if they are decoded the same. My experiance are that Whistler just use the first available data and do no comparison with a terrible result and Uniden seems to trigger RAS mode and ignores error correction whenever the number of errors reach a certain level even on non-RAS channels. It should be a flag in Sentinel to manually set RAS to the channels that actually uses it. I haven't heard of any cheap DMR radio that are able to ignore RAS.

/Ubbe

 

[slicerwizard]

All data transmitted thru air needs error correction and all radiosystems uses it. You can ignore RAS but then you cannot do error checking and error correction so even with a practicly noise free signal there will be errors in the data stream that cannot be detected and will give false results, like the wrong TG number are decoded.

Checksums are not error correction. You cannot correct bit errors using a checksum any more than you can correct parity errors using a single parity bit.

Lack of a valid checksum does not preclude error correction. The error correction data is unaffected by RAS.

I don't know how scanners cope with it, if they decode 4-5 dataframes with what should be the same info and then selects to use the data from two frames if they are decoded the same.

Unlikely. And it's a very poor solution to the problem.

My experiance are that Whistler just use the first available data and do no comparison with a terrible result and Uniden seems to trigger RAS mode and ignores error correction whenever the number of errors reach a certain level even on non-RAS channels. It should be a flag in Sentinel to manually set RAS to the channels that actually uses it. I haven't heard of any cheap DMR radio that are able to ignore RAS.

RAS can be reliably detected, so no need for a flag.

 

[Forts]

I've heard from a few people that the Anytone 868 & 878 will ignore RAS. Not personally tested by me however....

 

[CanesFan95]

Why would a single frequency system need a MotoTRBO radio?

If it's Cap+, a talk group can trunk around both slots, so you'd need a MotoTRBO radio to trunktrack that.

 

[slicerwizard]

If it's Cap+, a talk group can trunk around both slots, so you'd need a MotoTRBO radio to trunktrack that.

Can't a DMR radio be programmed to scan both slots?

 

[RRR]

Can't a DMR radio be programmed to scan both slots?

Yes, and it works.

And did y'all know, all new MotoTrbo radio systems sold now (legitimate ones) come with RAS enabled?

 

[IAmSixNine]

Can't a DMR radio be programmed to scan both slots?

As RRR stated yes. There is a 2 frequency (4 talk path) Cap plus system near me that a small police/fire dept use for public safety.
I programmed them in my XPR7550 as Cap plus but on my Hytera radio i put it in as pseudo trunking(monitors both time slots) and scan the two channels. Works well. The busier the system gets the less likely it will scan right so keep that in mind.