LCRA P25 - Dripping Springs site

[W5ATX]

I drove to both sites today and sat under them with my sds100, i disconnected the antenna and turned on the attenuator. I was able to receive the control channel at both sites. keep in mind, these sites are just a few miles apart and they are both line of site. is it possible for both sites to be transmitting the control channel on the same freq? the fcc records indicate 2 new frequencies, but they are saying they are at both sites: 5/cedar valley 50/150, and 6/dripping springs water tank. I dont know why they would build a new site on a water tank, assign it only 2 frequencies and make one of them a control channel, the same as the existing site just a few miles down the road. I submitted my findings to the database.

 

[rattlerbb01]

I drove to both sites today and sat under them with my sds100, i disconnected the antenna and turned on the attenuator. I was able to receive the control channel at both sites. keep in mind, these sites are just a few miles apart and they are both line of site. is it possible for both sites to be transmitting the control channel on the same freq? the fcc records indicate 2 new frequencies, but they are saying they are at both sites: 5/cedar valley 50/150, and 6/dripping springs water tank. I dont know why they would build a new site on a water tank, assign it only 2 frequencies and make one of them a control channel, the same as the existing site just a few miles down the road. I submitted my findings to the database.

Perhaps they are simulcasting that site? Are all frequencies and radio traffic the same at both sites?

 

[W5ATX]

I honeslty have no way to tell, i figured the new site would have a different rfss/site id. it still says 150/50. i need more attenuation, both sites are only 3 miles apart and are in line of sight of each other. with the antenna removed and which i thought was a 20dB pad, the sds is either picking up both sites or both are transmitting. i'll drive out there tomorrow and punch in some known cedar valley site 150/50 voice frequencies and see if they can be heard at the new water tank site. maybe someone "in the know" can chime in and tell us what their intentions are, if it's just basically a range extender with the same site ID or if they are going to abandon the cedar valley tower location, since the new water tank site is already owned by LCRA.

 

[rattlerbb01]

yeah, it doesn't make sense to put two sites so close to each other unless they are building a simulcast site. The only site they currently have that is simulcast is 120.20 Live Oak on the 800 MHz frequencies. With that said, we know they have been up to something making Cedar Valley/Dripping Springs 150.50 and Creedmoor 160.60. Maybe they are toying with Austin area simulcast cells?

Nonetheless, site 150.50 is updated with the new license and frequencies

 

[rattlerbb01]

I did notice that they have emission designator 9K70D1W assigned to the frequencies, but I can't tell if its always been there or if it was just added with the last modification because the FCC ULS website is timing out for me. That ED is for P25 LSM. 9K80D7W is for Phase 2 TDMA (H-DQPSK).

 

[W5ATX]

Simulcast. final answer

The S-meter on the sds100 is all over the place, but sitting under each site with the antenna removed and the ATT on, i learned both sites are transmitting the same control channel, site number and have the same frequencies. this is a first for lcra p25 that i've seen. so far the new dripping spgs water tank site on 290 near RR12 is a mirror of the existing dripping springs (cedar valley site) at 290 and trautwein rd where the opensky site is. maybe this a test run on the lcra owned water tank and they are going to disband the cedar valley 700 mhz p25 site and opensky site?