Placer Co VHF P25 System

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mkewman

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I'm hearing Lots and LOTS of Simulcasts on the Placer County VHF P25 System this week.

Grabbed and confirmed several talkgroups (and submitted them to the database)

107 - Western Placer Fire Dispatch Simulcast
105 - CHP Green Simulcast
104 - CHP Gold Simulcast
109 - Rocklin Police Dispatch Simulcast

And I'm fairly sure 106 - Placer Co Sheriff West Dispatch Simulcast

I am LOVING having CHP's simulcasts on this system. Green and Gold are both clear and have both Base and Mobile sides on the channel.

I have noticed that they don't have enough active frequencies though. During some transmissions at peak times, sometimes my 396t frantically switches between frequencies midway through the transmission.

I've got my HT connected to an antenna on a 100ft tower in Foothill Farms and I'll be running unitrunker on it tomorrow..
 

mkewman

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100% digital.

I'm having issues decoding the control channel on Unitrunker for some reason (probably because the radio i have the discriminator tap on is so old it doesn't have the correct tuning step) but as soon as i figure it out, or run some logging software using my 396t i'll post more finds. :)
 

abiu01

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I am really having great difficulty in decoding Placers P25 system on a GRE on a PSR-800. I have used the data as listed in RR, but cannot get it to work. The scanner shows strong signal and trunking, but no decoding of any TGs. I have tried several options but nothing seems to work in getting the talk groups.
Anybody have any thoughts? I also added the new TGs today.
 

kma371

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I'm hearing Lots and LOTS of Simulcasts on the Placer County VHF P25 System this week.

And I'm fairly sure 106 - Placer Co Sheriff West Dispatch Simulcast.

been monitoring tonight and i agree 106 is west dispatch
 

SCPD

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What are you using in your setup? I can't get Unitrunker to decode it :(
abiu01 mentions a PSR800 which has CC dump over the USB cable. The Unitrunker program has a bug affecting P25 VHF decoding by discriminator which I'm working to fix.
 

abiu01

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Been monitoring Placer P25 for several days now and here are some catches:

TG-101 this morning was running P25 encription. The encription was masked by telephone style busy signal.

TG-110 I still not sure what is on this TG. Last week it sounded ambulance to hospital. But later it sounded like it be Placer County Buses or Dial-A-Ride. Or non-emergency patient transfer. Still listening

TG-111 has been used very little, but this morning it sounded like Placer Sheriff Admin channel or sometimes called channel 5. Just not enough traffic on it to really tell yet.

It is going to be really interesting when they start turning on all of the rest of their sites. I have noticed that they have three new sites; one at the new brach jail in north Roseville, one on the ridge between Meadow Vista and Christen Valley, and one on Beacon Hill in Colfax (they bought some property from Union Pacific RR for that site). I am sure they are using their many other existing sites.
 

mkewman

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Have you tried Pro96Com?

sadly i don't have a compatible radio, I just have a 396T (not an XT)

I've got my unitrunker decoding at ~30% now, left it running since about 3pm yesterday so I've captured the following unidentified talkgroups with more than one hit:
101
102
108
111 (400+ hits since yesterday)
65536

What is "P 4" in the call type? I know 4 is the default priority, but what does p mean?

Again, my setup isn't ideal since my decoding rate isn't great... but i'll keep capturing.
 
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SCPD

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65536 is a fake group ID used to indicate a BSI or Base Station Identification. It's a short Morse Code announcement of the station license. The Info tab will show the call sign.

P is protected which is P25 terminology for encryption.
 

mkewman

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Currently, the CHP simulcast talkgroups are silent. Fire and sheriff dispatch simulcasts are still active.
UPDATE:
CHP went active again later that day, Sheriff and Fire are still active, Rocklin silent for the moment. The encrypted talkgroup is still active as well.

I dunno if it's propagation or what, but i have also noticed a slightly better signal from the system over the last 5 days.
 

bigRoN18

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I have just tapped an older scanner (Pro-2067) and was watching the control channel for a while with UniTrunker. I found it interesting to note that nearly all the traffic goes to 161.85000 MHz. After watching all this for a while, I decided to try to decode the signal with DSD on that frequency, because it is the most active. I'm not sure if it is because of a noisy tap or not a strong enough signal or what, but the audio sounds like crap. Some of the time, it is understandable, but most of the time it sounds like digital artifact with a hint of human. I'm not quite sure what "inlvl" numbers mean, but I'm getting numbers of 22-25%, in case anyone following this forum has any experience with DSD.
 

abiu01

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Placer P25

I have been monitoring Placer's P25 for the last couple of months using a GRE-800.
You are right, the audio is horrible, most of the time you can't understand what the mobiles are saying.
The base is somewhat better. I am within a couple of miles of their tower in Auburn and have a super strong signal that is is full quieting. I do not know if a Uniden would be any better. Hopefully the system will get better in the future when they get it built out.

By the way, I can copy Beale AFB P25 system here and it is perfect on the GRE800.

Dave
 

apx7000

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I've been monitoring Placer's P25 and agree that 106 is PCSO West. Dont know if that will change or not. My relative managed the Comms dept. for PCSO and worked on this P25 system for many years. I spoke with him about Chp being simulcast on the system and that was put in place so deputies could monitor with ease. For now I monitor with my uniden 396t, but I will purchase a Motorola or Icom radio in the near future and have this system programmed in once all is finished.
 
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