Lcra p25

[KI5IRE]

Has anyone else noticed several talkgroups im Hays County that are listed as TDMA in the database are running either FDMA or mixed mode? I have been picking up a lot of traffic that is supposed to be TDMA consistently on the San Marcos site recently on my BCD396xt that is Phase I only.

 

[rattlerbb01]

Has anyone else noticed several talkgroups im Hays County that are listed as TDMA in the database are running either FDMA or mixed mode? I have been picking up a lot of traffic that is supposed to be TDMA consistently on the San Marcos site recently on my BCD396xt that is Phase I only.

If a talk group is seen in TDMA mode by a scanner or control channel monitoring software, we update the mode in the database. This means that all users at that time are using Phase 2. If a single user logs on to the talkgroup that is only FDMA capable, then all users will revert to Phase 1 until that radio logs off.

 

[rattlerbb01]

I should add that when we update the mode it is to show listeners that they will be missing radio traffic in those locations if their scanner does not do Phase 2.

 

[ttkoestner]

Not that this is earth shattering news but the Boerne LCRA site is now showing Phase 2.

I'm not that tech savy on scanning. Can you tell me what this actually means? And will my 436HP still pick up the new system?

 

[rattlerbb01]

I'm not that tech savy on scanning. Can you tell me what this actually means? And will my 436HP still pick up the new system?

You would not notice any difference. Phase 2 audio is supported out of the box on the 436HP.

 

[boernegang]

I have a 396xt that I am using to feed Pro96Com for the LCRA Boerne site. Just recently I noticed that the site is now displaying phase 2. I started looking around in Pro96Com on the feed from that site and noticed some changes to the frequencies listed. Is this a normal screen for a phase 2 site???

 

[rattlerbb01]

I have a 396xt that I am using to feed Pro96Com for the LCRA Boerne site. Just recently I noticed that the site is now displaying phase 2. I started looking around in Pro96Com on the feed from that site and noticed some changes to the frequencies listed. Is this a normal screen for a phase 2 site??? View attachment 102963View attachment 102964

The duplicated frequencies at the bottom are each slot in a Phase 2 transmission. They will show up as the 08-xxx.xxxxx channels. Phase 1 channels carry only one digital conversation at a time, while Phase 2 channels can carry 2 conversations that are separated by time slots. The controller for the site will assign the frequencies dynamically based on the mode of the talkgroup.

 

[rattlerbb01]

Fayette County SO is now Phase 2

 

[boernegang]

The duplicated frequencies at the bottom are each slot in a Phase 2 transmission. They will show up as the 08-xxx.xxxxx channels. Phase 1 channels carry only one digital conversation at a time, while Phase 2 channels can carry 2 conversations that are separated by time slots. The controller for the site will assign the frequencies dynamically based on the mode of the talkgroup.

Thank you for the explanation. The site is showing Phase 1 again but the TDMA Frequencies still show up. I was looking this morning at the Channel grant trace and did see one of the consoles at dispatch was on the TDMA frequencies. I guess they are switching to phase 2?? Would this require new radios for all the departments??

 

[rattlerbb01]

Thank you for the explanation. The site is showing Phase 1 again but the TDMA Frequencies still show up. I was looking this morning at the Channel grant trace and did see one of the consoles at dispatch was on the TDMA frequencies. I guess they are switching to phase 2?? Would this require new radios for all the departments??

Im not sure what radios they carry honestly. The console could be phase 2 ready long before everybody else. All the radios present on the talkgroup would have to be phase 2 before the system would allow the talkgroup to go TDMA.

 

[KG1ADP]

The console does not determine the modulation of the talkgroup due to the console being hardline to the core. The subscriber determines the modulation.

 

[HiddenLefty]

Brownwood/Brown County is now joining this system and are at least partially online. Nobody will give me any information officially, and they're treating it like a national security issue when I ask, so I'm having to do things beyond the hard way and go discovery and search mode on the SDS200 and attempt to figure out things by brute force. If there's any way to be able to actually confirm the site information like what's the control channels and such I'd love to know because this is not as easy as it was in the analog world or even finding a single digital frequency. If there's someone maybe at LCRA who will actually respond to a request with the information to update the database with what's an obviously existing new site and talkgroups, I'd love to know how to contact them well because it seems they do not respond to general or FOIA request so far.

 

[rattlerbb01]

Brownwood/Brown County is now joining this system and are at least partially online. Nobody will give me any information officially, and they're treating it like a national security issue when I ask, so I'm having to do things beyond the hard way and go discovery and search mode on the SDS200 and attempt to figure out things by brute force. If there's any way to be able to actually confirm the site information like what's the control channels and such I'd love to know because this is not as easy as it was in the analog world or even finding a single digital frequency. If there's someone maybe at LCRA who will actually respond to a request with the information to update the database with what's an obviously existing new site and talkgroups, I'd love to know how to contact them well because it seems they do not respond to general or FOIA request so far.

With your SDS200, search the 769-775 range for a control channel. While scanning, hit CHANNEL, 769.000, CHANNEL and it will park on 769.000. You then hit RESUME and it will begin scanning through the 700 PS Band. You should find a control channel in that range since they aren’t licensed for any trunk frequencies. LCRA uses many sites with state licenses which don’t show up in the FCC database. Once you find the control channel it should say a site number and system (200 is LCRA). Make a new P25 system in your favorites list you want it to be in and plug that control channel in as the first frequency, then in the system options set the ID Search to ON. Then scan the system and see what pops up. If the control channel changes, repeat the first step and plug the new frequency into the system site. Until someone with DSD+ or Unitrunker gets to monitor the site, this will be the only way to find talkgroups and other info.

 

[HiddenLefty]

With your SDS200, search the 769-775 range for a control channel. While scanning, hit CHANNEL, 769.000, CHANNEL and it will park on 769.000. You then hit RESUME and it will begin scanning through the 700 PS Band. You should find a control channel in that range since they aren’t licensed for any trunk frequencies. LCRA uses many sites with state licenses which don’t show up in the FCC database. Once you find the control channel it should say a site number and system (200 is LCRA). Make a new P25 system in your favorites list you want it to be in and plug that control channel in as the first frequency, then in the system options set the ID Search to ON. Then scan the system and see what pops up. If the control channel changes, repeat the first step and plug the new frequency into the system site. Until someone with DSD+ or Unitrunker gets to monitor the site, this will be the only way to find talkgroups and other info.

I may just have to see what I can get into with Unitrunker. Worst case I've gotten nowhere further than what I have now and I've got nothing to lose by trying.

 

[rattlerbb01]

I may just have to see what I can get into with Unitrunker. Worst case I've gotten nowhere further than what I have now and I've got nothing to lose by trying.

I invested in a SDR to run it recently. Before that I had always used a tapped scanner with an aux cable. They have package deals that are pretty cheap online. The forums and the RTLSDR website have pretty much all the info to set it up. The more folks we have around the state having fun with this the better the database will be.

 

[HiddenLefty]

I invested in a SDR to run it recently. Before that I had always used a tapped scanner with an aux cable. They have package deals that are pretty cheap online. The forums and the RTLSDR website have pretty much all the info to set it up. The more folks we have around the state having fun with this the better the database will be.

I just got a couple of those exact RTL SDR that are listed on the website so I don't need to tie up a scanner. I have far more spare USB ports and antennas than those!

 

[HiddenLefty]

Official response from LCRA about how they think they're exempt from FOIA for the record:

"For security reasons, LCRA does not provide radio system sites, frequencies or talkgroup assignments to the public, as outside access can interfere with emergency response."

 

[rattlerbb01]

Official response from LCRA about how they think they're exempt from FOIA for the record:

"For security reasons, LCRA does not provide radio system sites, frequencies or talkgroup assignments to the public, as outside access can interfere with emergency response."

I wouldn’t worry, if it’s not encrypted it’ll show up eventually. It’s nice to have a whole fleet map programmed in and ready to scan, but if a.) it isn’t ever used or b.) it’s encrypted then it just takes up memory.