LCRA Site 155-055

[cferguson4809]

I’ve noticed some changes on the LCRA system over the past few days, specifically in the San Marcos area. Site 104 is no longer accessible. However, a new site—155-055—has appeared, although it does not show up in the current database.

Using Unitrunker, I was able to connect to this new site, but the waveform displayed in the scope looks very different from anything I’ve previously seen while monitoring this system. I’ve included a photo for reference.

In addition, I’ve noticed that the traffic coming through this site is missing certain information that was previously present. For example, I’m no longer seeing updates related to radio affiliations or data transmissions. Roughly 75% of the voice traffic is now missing source IDs, and the calls without source IDs also no longer display the call type (such as 4, P4, etc.).

My gut feeling is that this may be some sort of Phase II upgrade or perhaps a transition to a simulcast system.

Interestingly, one of my agency-programmed radios is able to connect to this new site without any issues—I can hear traffic just as before. However, a different radio, programmed by another agency, cannot receive this site at all, and I’m only hearing minimal traffic compared to the other radio.

I’ve done a quick comparison of the code plugs from both radios and haven’t found any significant differences.

Has anyone else noticed this or have any insight into what might be happening?

 

[Boingel331]

Very interesting, does this site show up in the neighbor site lists from other sites?
I'll take a look at it with SDRTrunk from here.

 

[cferguson4809]

Very interesting, are you receiving from San Marcos? Does this site show up in the neighbor site lists from other sites?
I'll take a look at it with SDRTrunk from here.

Yea, I am just south of SM but could in the past Rx 104-004 very easily. I checked and Wimberley no longer shows 104 as a neighbor site but it does show 155.

 

[Boingel331]

Yea, I am just south of SM but could in the past Rx 104-004 very easily. I checked and Wimberley no longer shows 104 as a neighbor site but it does show 155.

I can no longer RX 104 at all anymore. It has not moved anywhere in the 7-8-900MHz spectrum either.
155 is on the same frequency 104 was on. I was initially having some trouble reliably decoding it but switching SDRTrunk to Linear Simulcast Modulation (LSM) resolved all issues and is now decoding everything as expected.
I believe 155 has fully replaced 104. My FFT shows the site now has a thicker and smoother signature, probably due to it now being CQPSK modulation.
Correct me if I'm wrong, but can this be considered LCRA's first simulcast site?
If so, the next step is to see where and how far we can receive this new site.

 

[cferguson4809]

Interestingly enough, I noticed after looking at my code plugs again, the radio that CAN receive 155 has LCRA set to CQPSK and the one that can not is set to C4FM I didn't notice that at the time I originally posted this.
Edit to Add:
Differences noted:
-Motorola proprietary features is checked on the 4k and unchecked on the 7k
-WUID validity support is unchecked on the 4k and checked on the 7k
-Digital modulator type is CQPSK on the 4k and C4FM on the 7k

I did not check the control channel frequencies line by line BUT they appear to have the same number. I also don’t know where the setting for allowing affiliation on sites and control channels not programmed into the radio (Enhanced CC Scan in Harris) is located in Motorola CPS.

 

[rattlerbb01]

If yall can verify the new channel line-up and other reported data (NAC, Neighbors) we can update the database. The FCC license WREW251 only covers three frequencies at that site. Dripping Springs/Cedar Valley and Live Oak were presumed to be simulcast sites already, maybe we need to dig deeper and verify those too.

 

[cferguson4809]

If yall can verify the new channel line-up and other reported data (NAC, Neighbors) we can update the database. The FCC license WREW251 only covers three frequencies at that site. Dripping Springs/Cedar Valley and Live Oak were presumed to be simulcast sites already, maybe we need to dig deeper and verify those too.

I am not sure exactly what that license is because it's owned by Hays county and not LCRA and this does appear to still be an LCRA site showing a P25 ID of 92571-200. However I do have information about site 155.

*NOTE* As stated in the original post, Unitrunker is not reliably decoding all of the information so this may be incomplete. If anyone has any ideas I am happy to try and troubleshoot.

NAC: 200
Freq: 769.53125, 770.30625, 771.50625, 772.28125, 773.58125, 774.20625, 774.33125
Control: 00-0366 (773.58125)
Peers: 114, 123, 126, 150, 160
Band Plan: 769.00625/12.5khz/1 slot, 851.00000/12.5khz/1 slot, 769.00625/12.5khz/2 slot, 851.00000/12.5khz/2 slot,

Let me know what else you need after I hear back from you I will submit the change form for the database.

 

[Project25_MASTR]

Interestingly enough, I noticed after looking at my code plugs again, the radio that CAN receive 155 has LCRA set to CQPSK and the one that can not is set to C4FM I didn't notice that at the time I originally posted this.
Edit to Add:
Differences noted:
-Motorola proprietary features is checked on the 4k and unchecked on the 7k
-WUID validity support is unchecked on the 4k and checked on the 7k
-Digital modulator type is CQPSK on the 4k and C4FM on the 7k

I did not check the control channel frequencies line by line BUT they appear to have the same number. I also don’t know where the setting for allowing affiliation on sites and control channels not programmed into the radio (Enhanced CC Scan in Harris) is located in Motorola CPS.

Mot Prop Features shouldn't matter on a VIDA core. Specifically relates to Astro 25. WUID Validity...depends on the firmware in the SU. R21 and newer firmware it shouldn't be required for LCRA though. My legacy codeplugs have it enabled but my newer (and more current) codeplugs don't (and that has also been confirmed with the LCRA radio shop). The Motorola standard is to leave any 700/800 MHz or Phase 2 system with CQPSK set, newer firmware shouldn't actually care though.

As far as the last bit, settings allowing affiliation on specific sites are actually a Harris proprietary feature. Only one system in Texas actually uses it (Costal Bend maybe?) because it is using a quirky setup from RF Technologies that doesn't utilize interconnected site controllers. With P25, it is the system that tells the radio where it can and cannot roam to and affiliate at. Add new sites to a system, the radio will learn these sites from control channel adjacent data and following the band plan. Fun test, if you have the ability, is to actually remove all valid control channels from your control channel tables and enable spectrum wide scanning (Full Spectrum Scan on EFJ and BK). The radio will search the programmed control channels and if an active one is not found it will begin scanning for a control channel advertising a valid SysID following the band plan in the radio until it finds something.

The only equivalent on other vendors radios is the site preferences which...you'll get mixed reviews on whether or not those should be utilized on the subscriber.

 

[cferguson4809]

We do have a few personalities locked to GATRRS-40 (Bastrop) the county had a new guy program one of our radios and he forgot to restrict those personalities to 40 and every time the radio would switch to a different site the affiliation would be blocked. So somehow GATRRS does allow certain talk groups on only specific sites. I found this out when I had to call the OEM director because the radio was not working. 😔

 

[cferguson4809]

I am not sure exactly what that license is because it's owned by Hays county and not LCRA and this does appear to still be an LCRA site showing a P25 ID of 92571-200. However I do have information about site 155.

*NOTE* As stated in the original post, Unitrunker is not reliably decoding all of the information so this may be incomplete. If anyone has any ideas I am happy to try and troubleshoot.

NAC: 200
Freq: 769.53125, 770.30625, 771.50625, 772.28125, 773.58125, 774.20625, 774.33125
Control: 00-0366 (773.58125)
Peers: 114, 123, 126, 150, 160
Band Plan: 769.00625/12.5khz/1 slot, 851.00000/12.5khz/1 slot, 769.00625/12.5khz/2 slot, 851.00000/12.5khz/2 slot,

Let me know what else you need after I hear back from you I will submit the change form for the database.

Being connected longer, and finding a new control channel (774.33125) that is more reliable. Peers added should be 103 and 107. I would edit my post but the server said it's too old.

 

[556223]

I got a CC from SDR Trunk for the SM site 774.20625 and Unitrunker will not even decode it. This is weird as neighboring Simulcast site from Comal Co vhf and AT Sim 7 I could decode with Unitrunker

 

[556223]

This is what my SDR Trunk saw today, It wont let me copy and paste

 

[Project25_MASTR]

I got a CC from SDR Trunk for the SM site 774.20625 and Unitrunker will not even decode it. This is weird as neighboring Simulcast site from Comal Co vhf and AT Sim 7 I could decode with Unitrunker

Well considering Comal is VHF and Decker Geo is 800 MHz…my guess is Band 14 is wiping the front end out of your SDR on 700 MHz.

 

[cferguson4809]

Well considering Comal is VHF and Decker Geo is 800 MHz…my guess is Band 14 is wiping the front end out of your SDR on 700 MHz.

That’s an interesting theory and actually makes sense, my radio connects just fine but the SDR and my Unication G4 will not connect to it at all I even set the G4 to band scan to find any control channel. Not just the ones I programmed.

 

[556223]

Well considering Comal is VHF and Decker Geo is 800 MHz…my guess is Band 14 is wiping the front end out of your SDR on 700 MHz.

I forgot to mention that there is no issue with Unitrunker on AARRS

 

[556223]

Thank U for who ever submitted the SM Tower update to RR, I got to try and figure out how to add the Zorn hwy 123 / FM1979 LCRA Power Substation 200ft tower as a SM Simulcast location

 

[rattlerbb01]

Thank U for who ever submitted the SM Tower update to RR, I got to try and figure out how to add the Zorn hwy 123 / FM1979 LCRA Power Substation 200ft tower as a SM Simulcast location

What you can do is get the GPS of the known tower sites and we can triangulate the center if you want to get precise, but going center city and setting an appropriate radius is probably just about all we really need.

 

[556223]

What you can do is get the GPS of the known tower sites and we can triangulate the center if you want to get precise, but going center city and setting an appropriate radius is probably just about all we really need.

29°46'22.5"N 97°57'05.3"W
Zorn SM Simulcast Site

 

[cferguson4809]

Thank U for who ever submitted the SM Tower update to RR, I got to try and figure out how to add the Zorn hwy 123 / FM1979 LCRA Power Substation 200ft tower as a SM Simulcast location

I did, you're welcome.

What you can do is get the GPS of the known tower sites and we can triangulate the center if you want to get precise, but going center city and setting an appropriate radius is probably just about all we really need.

How would one go about doing this without RDF equipment. I don't mind doing the legwork but I do not have any RDF equipment.

 

[556223]

I see hex 8F Site on my SDR Trunk "Details Tab" in failure condition Downlink RX 851.1000 Uplink RX 806.1000 that is not in the RR LCRA Site List and since Live Oak is the only one that uses 800Mhz thru LCRA is this a possible replacement or Lockhart Tower ?