SDS100/SDS200: DMR Help

[W5JLF]

I just programmed my local school district (DMR) into my SDS100. It scans the channels but when it stops on an active channel there is no sound. The modulation is set to NFM and the service type is set to Custom 1. What do I have wrong?

 

[Whiskey3JMC]

Can you post the RR database link (if known) to this thread? Have you ruled out encryption as a possibility? Have you experimented with different filters? Menu > Manage Favorites > [Choose Favorite] > Review & Edit System > [Choose System] > Edit Site > [Choose Site] > Set Filter

 

[ka3jjz]

Do you have the DMR upgrade installed? Mike

 

[W5JLF]

Can you post the RR database link (if known) to this thread? Have you ruled out encryption as a possibility? Have you experimented with different filters? Menu > Manage Favorites > [Choose Favorite] > Review & Edit System > [Choose System] > Edit Site > [Choose Site] > Set Filter

To my knowledge it is not in the RR database. It is not encrypted. I have not experimented with filter changes.

 

[W5JLF]

Do you have the DMR upgrade installed? Mike

Yes it has the DMR upgrade.

 

[Whiskey3JMC]

To my knowledge it is not in the RR database. It is not encrypted. I have not experimented with filter changes.

Please do so and report back. Do talkgroups, color code(s), etc appear on the screen? Is this a conventional frequency (DMR one frequency) or MotoTRBO trunked radio system (CON+ or Cap+)? If the latter you'll need to figure out LCNs and ensure correct color code(s) is (are) entered since the info isn't known to the DB

 

[W5JLF]

Please do so and report back. Do talkgroups, color code(s), etc appear on the screen? Is this a conventional frequency (DMR one frequency) or MotoTRBO trunked radio system (CON+ or Cap+)? If the latter you'll need to figure out LCNs and ensure correct color code(s) is (are) entered since the info isn't known to the DB

I have them in as conventional. On my display they show as “CAP+” as Digital Status for whatever this tells you.

 

[Whiskey3JMC]

I have them in as conventional. On my display they show as “CAP+” as Digital Status for whatever this tells you.

There lies your problem. Sounds like the scanner is landing on a CAP+ rest channel which emits data bursts every few seconds and no audio (more info here). This needs to be programmed as a MOTOTRBO trunked system. You'll also need access to the FCC license so you can fill in possible missing frequencies (keeping in mind that just because they're listed on the license doesn't guarantee they're all indeed in use) & run LCN Finder (Menu > Analyze > LCN Finder) to determine correct LCN order so the system can be tracked properly. Being a school district, this would best be achieved during school hours of course

 

[hiegtx]

I have them in as conventional. On my display they show as “CAP+” as Digital Status for whatever this tells you.

Which local school system? Or a link to the FCC license?

Many of the DFW area school districts are not in the database, either not at all, or only a small portion of their operations. A great many of them are licensed for DMR, with some, instead, licensed for NXDN. Unfortunately, with the semester either ended, or ending soon, the level of radio activity will drop considerably, making it harder to map the system out until school resumes in the fall. Summer school, in some districts, may provide some opportunities, but still activity will not be as prevalent as during a regular spring or fall semester.

 

[GlobalNorth]

Tracking school frequencies drops off after classes let out and will become infrequent in July. As school approaches, the radio traffic will increase as does maintenance, operations, and teachers make their way back prior to classes in the fall.

Now's a good time to catch whatever traffic is there and program the DB.

 

[CanesFan95]

Not familiar with the scanner, but I believe NFM is basically considered an analog mode, but Cap+ is digital.

 

[Whiskey3JMC]

Not familiar with the scanner, but I believe NFM is basically considered an analog mode, but Cap+ is digital.

Narrow FM modulation doesn't define whether a signal is analog vs. digital, but rather the bandwidth within which the signal is carried. It is described pretty well in post #3 on this thread and also this wiki