Sacramento P25 system

DANE_KI6OAA

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Scannerboy02, the G5, do you know how many channels it can store?

Welcome to the new (not really new, this P25 system has been on the air since 2013) world of Project 25.

As many of you have, or will soon find out, this system is going to be much more difficult to hear than the analog system was. This is due to the P25 systems use of Linear Simulcast Modulation (LSM) and a lot of the older scanners have extreme difficulty in processing this type of modulation.

The difference between being able to receive traffic or not receive traffic can be as little as a few feet, it's all about location, location, location. If you have a P25 Phase I(1) capable scanner and are not able to receive traffic try moving the scanner (or more so the antenna) around a little. You can also try orientating the antenna horizontal instead of vertical or remove the antenna completely and maybe try something like a paperclip (just be careful not to damage the scanners antenna jack). The biggest help I can give for someone having reception trouble is try things that will REDUCE the amount of signal you are receiving, not increase it. Good reception will require a very careful balance of just the right amount of signal.

As for scanners (and other devices) that handle LSM well.
From worst to best, *in my opinion*
Whistler TRX-1 and TRX-2.
Uniden BCD436HP and BCD536HP.
Uniden SDS100 and SDS200.
Unication G4 and G5. (Note, these are not technically scanners but they receive VERY well.)
Additionally, I used links to places I have purchased scanners in the past but most of these can be purchased from many different dealers.
 

sharward

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Sacramento (Natomas), CA, USA
I just saw bigRoN18's post in this thread in which he describes his SDRTrunk & Airspy Mini SDR Tuner setup.

Color me inspired.

I was looking at replacement scanners, but I got sticker shock -- if too expensive, my feed might be down for good.

However, as he demonstrated, now that I see I might be able to get a virtual scanner set up on my computer, at a fraction of the cost of a modern scanner device.

I have a mini tower Lenovo PC that is a few years old but still very serviceable, powered on 24x7 with a hardwire Ethernet connection to my Internet router. It's how I have run my feed for years, connected to the headphone jack of a trusty Radio Shack PRO-107 that isn't advanced enough to pick up P25 Phase 1 signals. It's running Windows 10, dual core 3 GHz with 4 GB of RAM. I don't use the machine for much of anything else. I can probably upgrade the RAM if necessary.

I'm good with computers and tech and have a fair bit of knowledge of how scanners and trunking works.

I just took the plunge, ordering an Airspy Mini SDR, an 800 MHz antenna, and an angle adapter. As soon as it arrives, hopefully before the weekend, I'll download and install SDRTrunk and see if I can get things up and running.

Cheers and wish me luck.
 

mcjones2013

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If you can learn it, SDRs are great. I would be fantastic if you (or anyone) could get *separate* feeds for all the dispatch channels in the county. At the very least for SSD and SPD.

My computer at home can barely handle running Unitrunker 24/7, otherwise, I'd try to do the feeds. Maybe in the future.
 

sharward

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Sacramento (Natomas), CA, USA
If you can learn it, SDRs are great. I would be fantastic if you (or anyone) could get *separate* feeds for all the dispatch channels in the county. At the very least for SSD and SPD.
If and when I can get Sacramento Police Department - North Command (Channel 1) feed back up and running, I can explore what it would take to get another channel or two into a dedicated feed. Tech tips welcomed.
 

scannerboy02

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If and when I can get Sacramento Police Department - North Command (Channel 1) feed back up and running, I can explore what it would take to get another channel or two into a dedicated feed. Tech tips welcomed.
If you have tech knowledge you shouldn't have any trouble getting SDRTrunk setup. I personally use 4 of these SDR's for my setups and they work very well.

The nice part about SDRTrunk is that it will configure the SDR settings for you and will allow you to run multiple systems at the same time as well as setup multiple feeds so you could (PC power dependent) have different feeds coming out of one computer.

Both SDRTrunk and Trunk Recorder have some different limitations and that's why I run both to get the best of both worlds but if you're only looking to feed a handful of channels SDRTrunk will work great.

If you're going to go this way please look into either the Broadcastify Calls platform or OpenMHz (Trunk Recorder only) platform.
 

DANE_KI6OAA

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If you have tech knowledge you shouldn't have any trouble getting SDRTrunk setup. I personally use 4 of these SDR's for my setups and they work very well.

The nice part about SDRTrunk is that it will configure the SDR settings for you and will allow you to run multiple systems at the same time as well as setup multiple feeds so you could (PC power dependent) have different feeds coming out of one computer.

Both SDRTrunk and Trunk Recorder have some different limitations and that's why I run both to get the best of both worlds but if you're only looking to feed a handful of channels SDRTrunk will work great.

If you're going to go this way please look into either the Broadcastify Calls platform or OpenMHz (Trunk Recorder only) platform.
Great information man! Thank you so much! I'm sure as soon as I get my SDR's I will have more questions if you don't mind.
 

bigRoN18

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Check this out
I find SDRTrunk to be much easier to use. I've used DSD+ Fastlane for a little as I was transitioning to SDRTrunk. I have now been using SDRTrunk for a while. Even though it is maintained by one guy, Denny Sheirer, he has been making a lot of changes over the past couple years, with little updates constantly updated on the Github site. There is a Google Groups group for the software where we discuss the development and help each other out in our setups. Once you set it up, it is very easy to create multiple streams. I usually send a feed to Broadcastify, but I like to listen to law enforcement tactical channels (provided they aren't using encryption) which I am expressly forbidden to share to Broadcastify. It is for this reason that I have setup my own IceCast2 server. I create many different streams for different groups of talkgroups that I may be interested to listen to at different times. Using an app on my iPhone called "Action Scanner" I can plug in all of my streams and listen to all of them or disable all but those I wish to listen to at the time.
 

scanfan2112

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Yes. I have one that I've been using just for tac channels for months and it works perfectly. I programmed one set of scanners with all the P25 talkgroups and had them running alongside the old analog trunktrackers for a seamless transition. In fact it worked so well that I didn't even know the switchover happened until kgowen4444 got a call from a friend telling him that his feed went quiet.
Thank you. I reprogrammed it and all is well... I forgot it was even P25 capable...
 

mcjones2013

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Starting at 8 a.m. this morning (6/4), 10 frequency pairs from Site 1 and Site 2 were brought over to Site 12 as voice channels. This brings the total channels to 30 for Site 12, which maxes out the number of channels allowed for a site.

However, around 12:20 p.m., they appear to have been taken out of the available voice channel pool. This is likely temporary.

SRRCSSite12_30Channels.PNG

The rest of the Site 1 and Site 2 frequency pairs (with the exception of three or four) appear to be in the process of being converted to P25 conventional tactical channels. That is being discussed here: Sacramento County Conventional P25 Tacticals
 

bigRoN18

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Starting at 8 a.m. this morning (6/4), 10 frequency pairs from Site 1 and Site 2 were brought over to Site 12 as voice channels. This brings the total channels to 30 for Site 12, which maxes out the number of channels allowed for a site.

However, around 12:20 p.m., they appear to have been taken out of the available voice channel pool. This is likely temporary.

View attachment 86111

The rest of the Site 1 and Site 2 frequency pairs (with the exception of three or four) appear to be in the process of being converted to P25 conventional tactical channels. That is being discussed here: Sacramento County Conventional P25 Tacticals
If they need MORE than 30 channels, they may have to go to Phase 2. Can a system be hybrid, where some are Phase 1 and some are Phase 2? I am not aware of any Phase 2 systems in our area but at least the software I use can do both and the setup is exactly the same. The control channel on a Phase 2 system is still a Phase 1 control channel, it is just the voice channels that are Phase 2.
 

gmclam

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Can a system be hybrid, where some are Phase 1 and some are Phase 2?
A Phase II system supports Phase I TGs.

I am not aware of any Phase 2 systems in our area but at least the software I use can do both and the setup is exactly the same.
I haven't found one here either. But there are certainly a lot up north in Oregon & Washington.
 

KG7PBS

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Reno NV
If they need MORE than 30 channels, they may have to go to Phase 2. Can a system be hybrid, where some are Phase 1 and some are Phase 2? I am not aware of any Phase 2 systems in our area but at least the software I use can do both and the setup is exactly the same. The control channel on a Phase 2 system is still a Phase 1 control channel, it is just the voice channels that are Phase 2.
Okay Yes there can be Mix Mode System. P1 and TDMA. But for that to happen you have to put in a Device at each site. That cost like 10,000 each. I don't remember what the device is called its been a minute when I talked with my Motorola Friend. Its not cost effective to do that. If the SRRCS is going to TDMA then all Talk Groups will be TDMA. Not mixed FDMA/TDMA
 

etofsrud

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Starting at 8 a.m. this morning (6/4), 10 frequency pairs from Site 1 and Site 2 were brought over to Site 12 as voice channels. This brings the total channels to 30 for Site 12, which maxes out the number of channels allowed for a site.

However, around 12:20 p.m., they appear to have been taken out of the available voice channel pool. This is likely temporary.

View attachment 86111

The rest of the Site 1 and Site 2 frequency pairs (with the exception of three or four) appear to be in the process of being converted to P25 conventional tactical channels. That is being discussed here: Sacramento County Conventional P25 Tacticals
So do I need to add these 10 frequency to my radio, under site 12? That would make a total of 30 frequencies for site 12.
 

mcjones2013

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Sacramento, Calif.
So do I need to add these 10 frequency my radio, under site 12? That would make a total of 30 frequencies for site 12.
Most scanners only need the control channel and alternate control channels programmed. Your scanner will know what voice channel to go to. 852.3500, 853.1875, 853.4500, 853.8750.
 

scannerboy02

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If they need MORE than 30 channels, they may have to go to Phase 2. Can a system be hybrid, where some are Phase 1 and some are Phase 2? I am not aware of any Phase 2 systems in our area but at least the software I use can do both and the setup is exactly the same. The control channel on a Phase 2 system is still a Phase 1 control channel, it is just the voice channels that are Phase 2.
The maximum number of traffic channels is 29 (plus 1 active control channel) no matter if the site is Phase I or Phase II so site 12 is maxed out.

This is why I was a little surprised to see them move away from a "county" site and "city" site and go with one large site. The only way to reduce the loading now would be to add localized sites for specific users (like UCDMC, airport) or move some users off to another radio system.
 

dirtrat

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Dec 19, 2002
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The maximum number of traffic channels is 29 (plus 1 active control channel) no matter if the site is Phase I or Phase II so site 12 is maxed out.

This is why I was a little surprised to see them move away from a "county" site and "city" site and go with one large site. The only way to reduce the loading now would be to add localized sites for specific users (like UCDMC, airport) or move some users off to another radio system.

30 Channels is a huge amount of talkpaths and very few systems have this many channels. This system will be able to accommodate a large amount of traffic even on FDMA. The problems with having a Phase II system is that many older generation radios cannot be upgraded to Phase II so very expensive P25 TDMA radios would need to be purchased by everyone if they have older XTS/XTL radios. Also multi-Site systems are very problematic when the system goes into a Site Trunking failure and patches and Multi-Selects need to be done by multiple agencies to accommodate communications from users affiliated on different sites. On a single site system this isn't an issue and dispatch centers only need to go on their local backup radios. The whole thing would be transparent to subscribers.
 
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