San Joaquin SO/Lodi PD P25 changes coming soon

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kma371

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Got word the San Joaquin Co Sheriff's Office and the Lodi Police Department will be updating to P25 digital within the next week or so. Someone was able to give me a heads up on the freqs (which stay the same) and the NAC codes.

DB has been updated accordingly.
 

KMA367

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Negative, Channel 3 will remain analog for some reason.
Perhaps for outside (not digital-capable) agencies to communicate with them? It's common with the digital agencies in L.A. County, for instance, to have what they usually call an "Access" channel for analog-only agencies.
 

kma371

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Likely so, however Stockton PDs channels are capable of mixed mode for non digital agencies. There are only a few left in San Joaquin County so that may change.
 

kma371

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Well, this hasn't happened yet. My understanding is programming isn't done...

Probably mid-late March
 

KD6RRR

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San Joaquin County SO testing P25 today

Listening to 460.1250, the SO's usual dispatch frequency, today there was traffic between a person sounding like she was located in the dispatch center and different mobile units identifying as, I think, "King North", "King Central", "King South" and sometimes as "King 701". The mobile units were radioing in from different street intersections around the county, doing radio checks on either different model radios, different modes, or both, from both "in vehicle" and "out of vehicle". They were using both analog as well as digital, to which the different personnel would refer to by different names. I heard them referencing "XTS analog in vehicle", XTS P25 in vehicle", "XTS analog out of vehicle", "XTS P25 out of vehicle", "ATX in vehicle", and ATX out of vehicle".

I was able to monitor them on both analog and P25 on my scanner. The P25 signal strength on my scanner meter was full scale, while the analog varied widely while the scanner sat in the same position.

Sounds like the switch is finally underway. The P25 traffic definitely seems to be coming from a wider coverage system, at least as far as my rubber duck wideband scanner antenna can tell.

As I continue to listen, I am led to wonder what all elements can effect the actual audio I am hearing. The actual "loudness" of the units voices as they tested the P25 radios were loud and clear on an ongoing basis. There was no difference in levels volume wise from the various units.

I bring this up because, when I listen to Stockton PD and Tracy PD on their respective P25 systems, the actual volume levels range widely, from barely audible to blow-you-out-of-the-chair loud.

When listening to the SO tests today, I did so from one fixed location using my handheld scanner, and was hearing only the same three or four units transmitting, in a comfortable, "non-stress" environment that the units could probably take the time to focus on their radio and speak clearly directly into the mic. Every transmission I heard was perfectly loud and clear.

When normally listening to Stockton and Tracy, I myself will normally be moving, as is my scanner or radio. Also I will use different receivers; either a handheld or mobile mounted scanner or a handheld radio. Then, of course, there is a wide ranging amount of variables I am listening to; officer running, in a vehicle, being covert, showing emotion, etc., etc., etc., all of which affect the mic hearing the voice and the transmitter being received by the system, etc. Through these day to day activities, the volume levels of the audio I hear on these P25 systems vary dramatically as well.

I have been monitoring, and transmitting on, all kinds of FM analog systems over the last 30 years, ranging from amateur radio to public safety, and have learned the various nuances encountered. Anyone have any thoughts on the differences in audio quality and if P25 systems display similar or completely new and different types of variations when compared to an "old fashioned" analog FM system?

I seem to have hijacked my own thread here. :)
 
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kma371

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P25 transition in progress, confirmed switched so far are:

460.1000 NAC 394 - Court Services
453.3250 NAC 395 - Jail - Main Jail/South Jail
453.5375 NAC 397 - Jail - ADSEG unit
 
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Sac916

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Listening to 460.1250, the SO's usual dispatch frequency, today there was traffic between a person sounding like she was located in the dispatch center and different mobile units identifying as, I think, "King North", "King Central", "King South" and sometimes as "King 701". The mobile units were radioing in from different street intersections around the county, doing radio checks on either different model radios, different modes, or both, from both "in vehicle" and "out of vehicle". They were using both analog as well as digital, to which the different personnel would refer to by different names. I heard them referencing "XTS analog in vehicle", XTS P25 in vehicle", "XTS analog out of vehicle", "XTS P25 out of vehicle", "ATX in vehicle", and ATX out of vehicle".

I was able to monitor them on both analog and P25 on my scanner. The P25 signal strength on my scanner meter was full scale, while the analog varied widely while the scanner sat in the same position.

Sounds like the switch is finally underway. The P25 traffic definitely seems to be coming from a wider coverage system, at least as far as my rubber duck wideband scanner antenna can tell.

As I continue to listen, I am led to wonder what all elements can effect the actual audio I am hearing. The actual "loudness" of the units voices as they tested the P25 radios were loud and clear on an ongoing basis. There was no difference in levels volume wise from the various units.

I bring this up because, when I listen to Stockton PD and Tracy PD on their respective P25 systems, the actual volume levels range widely, from barely audible to blow-you-out-of-the-chair loud.

When listening to the SO tests today, I did so from one fixed location using my handheld scanner, and was hearing only the same three or four units transmitting, in a comfortable, "non-stress" environment that the units could probably take the time to focus on their radio and speak clearly directly into the mic. Every transmission I heard was perfectly loud and clear.

When normally listening to Stockton and Tracy, I myself will normally be moving, as is my scanner or radio. Also I will use different receivers; either a handheld or mobile mounted scanner or a handheld radio. Then, of course, there is a wide ranging amount of variables I am listening to; officer running, in a vehicle, being covert, showing emotion, etc., etc., etc., all of which affect the mic hearing the voice and the transmitter being received by the system, etc. Through these day to day activities, the volume levels of the audio I hear on these P25 systems vary dramatically as well.

I have been monitoring, and transmitting on, all kinds of FM analog systems over the last 30 years, ranging from amateur radio to public safety, and have learned the various nuances encountered. Anyone have any thoughts on the differences in audio quality and if P25 systems display similar or completely new and different types of variations when compared to an "old fashioned" analog FM system?

I seem to have hijacked my own thread here. :)

Hearing San Joaquin 460.1250 NAC390 VERY loud and clear from Downtown Sacramento today.
 

russianspd

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460.125 ct 186.2

So has the switch actually happened? I am monitoring the old analog and picked up Lathrop 5 but it's been dead quiet for over 30 mins or so.
 

kma371

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Sounds like they did the same stupid 4095/1 talkgroup IDs for the dispatch channel.

Anyone know why they do this? 4095 TG is always the dispatcher and 1 TG is always the units.
 

kma371

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So has the switch actually happened? I am monitoring the old analog and picked up Lathrop 5 but it's been dead quiet for over 30 mins or so.
SO channel 2 (records) also switched. Has anyone confirmed Lodi PD? I can't copy them from my location.
 

kma371

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Another confirmed switch is the Juvenile Justice Center (JJC, Juvenile Hall) using same freq (453.525) and 598 NAC.

DB updated.
 

WayneH

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Anyone know why they do this? 4095 TG is always the dispatcher and 1 TG is always the units.
In order for consoles to operate over a digital talkgroup they need an added device called a DIU (Digital Interface Unit) before connecting to the RF infrastructure. It's responsible for the decoding and encoding (clear or encrypted) of the P25 voice carrier. With that encoding comes the RID and TGID. The defaults are RID 1 and TG 4095.

An old post of mine on it here.
 

kma371

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In order for consoles to operate over a digital talkgroup they need an added device called a DIU (Digital Interface Unit) before connecting to the RF infrastructure. It's responsible for the decoding and encoding (clear or encrypted) of the P25 voice carrier. With that encoding comes the RID and TGID. The defaults are RID 1 and TG 4095.

An old post of mine on it here.
Well Tracy PD doesn't do it so I think they (S/O) should :)
 

kma371

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i wonder how long it will be until they go paranoid...
..i mean... encrypted
That was the original plan, 100% encryption. I had a LONG talk about it to the IT guy about the cons of that idea. Maybe he listened ;)
 

kma371

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More changes NOT S/O related, University of Pacific changed as well as new Port of Stockton freqs. DB updated.
 
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