2020 SDR Guide Ep 6 : Trunk tracking Public Safety systems with UniTrunker and SDRTrunk

[@Michael_KD6TTC]

I just found your channel and I’m very impressed by all your effort in conveying complex information in an easy to understand manner. I’ve subscribed and looking forward to more! 73’s from Los Angeles, CA, US - KD6TTC

[@FrugalRadio]

Thanks for the kind comments Michael. I'm pleased you've found the channel and subscribed. Welcome!

[@Wayne-Pr]

Another great video, back in the "good old days" before everything went Apco 25 encrypted trunking I used to use both TrunkView & a "dedicated Moto trunk radio" to monitor all the MPT1327 VHF High trunking traffic in my state ( Victoria, Aust) including regional & metro Police, regional, metro & forest Fire, regional & metro Ambo's, Water authorities, metro & regional Trains, taxis, mobie speed camers, SES ( State Emergency Service ), Roads authority's & sheriff you name it it was great listening, then that faithful day come when everything come to a screaming halt. 😭 Our Metro Police service moved from a static in the clear N/W to a UHF Moto Apco 25 trunking encrypted N/W called MMR or ( Moto Mobile Radio) Regional police moved to a encrypted VHF Moto Apco 25 RMR Regional Mobile Radio N/W City metro Ambo's also moved to the same MMR UHF encrypted network as the metro cops ( different talk group as the metro cops.) Metro Trains moved to a new UHF encrypted N/W called GSMR ( Basically GSM for rail ) Regional rail just vanished. Taxis network moved to a UHF MotoBro trunking Encrypted N/W Regional volunteer Fire moved to a new VHF Tait I & Tait II trunking network ( currently in the clear) but for how much longer who knows ( not trackable by any current s/w you need a dedicated radio or a special uniden scanner only designed for regional fire personal ) Paid Forest fire moved to to the same VHF RMR Digital trunking N/W as the regional cops ( different talk group ) The water authorities moved to some weird untrackable 800Mhz encrypted trunk network. SES have moved to the same Moto VHF RMR network as the others still in the clear for the moment but who knows how much longer ( just a different talk group) Metro Fire moved from a static UHF N/W to the same UHF MMR N/W as the metro cops and ambo's still in the clear for the moment but who knows how much longer ( just a different talk group) Our roads authorities moved from a static UHF N/W to the same VHF RMR Encrypted N/W as the rest ( just a different talk group) Our sheriff moved to both the Moto Encrypted VHF RMR & the Moto Encrypted MMR UHF N/W as the cops ( just a different talk group ) Whilst the old MPR1327 now only carries less than a handful of very regional ambo's with a patched in the clear talk through network to both the MMR encrypted N/W and the VHF RMR N/W who knows for how much longer. 50% of our air traffic lands and takes off at our big international airports without any voice now its all done digitally by ACARS, CPDLC & Inmarsat voice. HF Aircomms are barley used in Aust now again its all ACARS, CPDLC & Inmarsat, I used to listen to a HF to sat link through Optus B3 but even thats gone now. A lot of our AM radio stations have either gone all together or have gine FM In the Australian capital territory also known as the ACT ( Canberra ) & the Australian Northern Territory Alice Springs & Darwin ( also known as the NT) ALL comms services are fully encrypted. On the rest of the east coast of Aust New South Wales ( NSW) & Queensland ( QLD) over 90% of all the comms traffic is encrypted. There are so many different trunk networks used un Aust including NXDN EDACS MOTOBRO DMR MMR RMR The list just goes on and on. Our state governments in Aust are obsessed with secure digital encryption. Hope that gives you a basic run down of comms traffic in Aust. Regards Wayne.

[@FrugalRadio]

Thanks for that comprehensive post Wayne! There has definitely been a big move towards encryption there, which is certainly difficult for us hobbyists. However if you are able to get the Talkgroups identified, you can still display the traffic on screen, even though you can't listen to it. Then you can see which areas are busy, and identify usage patterns. It is quite hard to do if the TGs weren't identified during the switchover. I've never heard of some of the trunking protocols being used there. As for aircraft, I haven't seen CPDLC replace local Radar, Approach & Tower frequencies around here, but certainly a most of the Area Control has gone that way. Thankfully it isn't encrypted and messages can be received and displayed with your SDR. You may well have set up a receiving station for that already as you seem to have a great grasp of the radio world!

[@KellyAnnM]

Thanks for the info Wayne, I'm also in Melbourne and I'm just starting to get into SDR. I didn't realise so little was in the clear, now I know what to expect at least! My hobby since April is collecting POCSAG's from CFA/FSV & Regional AV.

[@jonnporter6081]

Thanks for your videos. I'm not an electronics type person, and your videos explain things so that I can understand them. You're doing a great job.

[@FrugalRadio]

Thank you for your kind comments. I'm pleased the videos are helpful.

[@acestudioscouk-Ace-G0ACE]

Some very useful information, well presented. This series is getting better and better. Thank-you!

[@FrugalRadio]

Glad it is useful to you 🙂

[@richard_wenner]

Very impressive series. Thanks for sharing!

[@FrugalRadio]

Glad you're enjoying it Richard. Appreciate your comments.

[@humaxf1]

Will look into sdrtrunk for a mpt1327 system near by. Have used unitrunker in the past but can be fiddly. Thanks for the video, interesting and straight to the point.

[@FrugalRadio]

Let us know how it goes. I haven't seen an NPT1327 system in quite a few years!

[@hamrad88]

Awesome tutorial. Will SDRTrunk work with RSP SDRs? Hope you will do some shows on SDRuno.

[@FrugalRadio]

Cheers. I actually just got my first SDRPlay device, so SDRUno will make an appearance at some point! I'll also try the RSP on SDRTrunk and I'll report back!

[@hamrad88]

@@FrugalRadio That would be awesome.

[@RedLine_Renesis]

Why did you blur some the data. If it's public, what's there to hide? Serious question

[@FrugalRadio]

Good question. I choose to blur out information that is not publically available. Sometimes there are active talkgroups on a system that have not been publically identified. On occasions I have worked out who the user is, but I choose to keep that information private, since the data isn't "out there" in the open. Similarly, I will mute sections of audio that disclose personal information such as address, medical information, etc. I do not feel at liberty to share people's private information.

[@paulnortham]

Thanks again. So much to learn! Is the trunking system similar in the UK? Since I got my SDR I've realised how little I know is going on over the airwaves. Anyway, I'm sticking my airband dipole up today. Wish me luck!

[@FrugalRadio]

Best of luck getting the antenna up. Stay safe up that ladder Paul! As for UK, I responded to another comment on that. There may still be a little MPT1327 around, but must trucking is now digital Tetra (the Airwave system from 380-400 MHz which is almost exclusively encrypted), and DMR (which we will cover in Episode 7).

[@paulnortham]

@@FrugalRadio Thanks for the reply. A few tricky moments but got down safely - As did the children who spent the afternoon on the kitchen roof below me! It's not as high as I wanted but at least it gets away from some of the interference - I can now get BHX ATIS fairly reliably around the clock. Looking forward to the next video. P

[@odelljw]

Love your videos, I am looking to build a mobile unit for my local public safety depts. I currently have sdrtrunk running for p25 phase II what would you recommend to cover the UHF band which the fire paging system is still on here (orange county, NY) ? Love to hear what you mite recommend.

[@FrugalRadio]

Hi Jerry, thanks for your comments. What protocol is that UHF paging system using? If it is POCSAG or Flex, I would most likely use PDW, which is what I use here. I considered putting a Panasonic Toughbook in my car, hooking up to an SDR, but I never got round to it! Today I would consider a different approach : setting up the receive SDR at home, and reading / parsing/ filtering the logs with something like Node Red, generating a Web page with the filtered output, and just using a Web connected tablet in the car for display (or a smartphone). I haven't yet experimented with this type of set up, but was recently talking online with someone doing it for CPDLC transmissions. What methods have you considered?

[@odelljw]

@@FrugalRadio This is the info from radioref , 451.68750 WQCV570 B 151.4 PL E OC Fire Paging Fire Paging Simulcast FMN Fire Dispatch What software would you use to scan the uhf band on a sdr?

[@FrugalRadio]

Depends on what the desired outcome is. Do they broadcast data only, or is there also voice paging on the frequency? A PL tone suggests voice traffic, not just data. But for scanning UHF, a BCT15X scanner or any of the SDRs. They work just as well in UHF as VHF.

[@danedewaard8215]

Just wondering how SDRTrunk works with the RTL-SDR.COM v3 dongle and if it also requires two dongles as UniTrunker??? Thanks for the great video!

[@FrugalRadio]

The RTL-SDR v3 dongles work great with SDRTrunk! I would need 2 on that system because it the frequencies span over 5 MHz. If your local site frequencies cover less than 2 MHz, you would only need 1 RTL-SDR v3 to monitor Control Channel and Voice.

[@danedewaard8215]

Sorry to bother you again, just wondering if you used a antenna splitter when using two v3 dongles for trunking? If so, which one? I wonder how much loss there would be if just a "Y" adaptor was used??? Thanks!!! I was just thinking about it again, and thought that you are probably using two different antennas instead of splitting one antenna between the two dongles!?!?

[@FrugalRadio]

Hi Dan. I actually use a device called a multicoupler. It takes one antenna input, and electronically splits the signal 8 ways, ensuring there is no loss.

[@danedewaard8215]

Thank you sir, I will do some research on that!

[@prototype3a]

Seems I really do need to purchase an Airspy R2. I wanted one anyway for other purposes. Can you do a video on your MCA208M and how you connect everything?

[@FrugalRadio]

Yes, I am planning to do that at some point!

[@alanwallis2796]

Where would i find similar frequencies in the UK. or is there not enough to warrant looking ? regards

[@FrugalRadio]

There aren't many analog trunking systems in the UK. In fact the biggest one I know of seems to have been shut down. It was in the 174-225 MHz range and was used by Network Rail. MPT1327 was the type used in the UK in the past. Emergency Services there are now using a Nationwide digital trunked system called Airwave. It uses the Tetra protocol. Almost all areas are fully encrypted. I had success decoding some clear Tetra transmissions with the Tetra Net Monitor software and an RTL-SDR. You'll spot a lot of sites in the 380-400 MHz band. They are wide bandwidth (25 kHz) 4 slot carriers emitting a constant Control Channel. Lastly, DMR digital trunking networks are popular there, and a few NXDN networks have started to appear. Check the UHF band. Have a close look from 450-470 MHz. Demodulating DMR systems will be covered in Episode 7 🙂

[@alanwallis2796]

@@FrugalRadio Thank you for your reply, Ok I will have a look around and see what I can find, and will look out for Episode 7

[@chrispowell3664]

I enjoy your channel. Can you do a video on configuring DSDplus to decode digital modes with a tapped scanner. Lots of demo video on YT but nothing on setting up the software. Thanks.

[@FrugalRadio]

Great idea Chris. I don't use DSD Plus in that configuration, but I'll bear it in mind and see if I can come up with something in the future.

[@chrispowell3664]

@@FrugalRadio Thank you and keep up the great work.👏

[@dimmoos757]

Hi , thanks for useful clip. I found DMR local channel and when i try listen that with sdrtrunk, i see channel is locked and cant listen it. how can unlock this DMR channel? is there any program for do that?

[@FrugalRadio]

If some channels are appearing locked, it means your SDR is not able to span the full bandwidth of the system. You can use an SDR with higher bandwidth (Airspy mini or R2 for example). This means the tuner can span the entire width of the digital system and track the Control Channel and all Voice Channels simultaneously. Or you can add another lower bandwidth SDR. That way, when SDRTrunk is monitoring a Control Channel and wants to hop to a voice channel that is outside of its range, it will tune the 2nd dongle and use that for the audio. Hope that helps!

[@dimmoos757]

@@FrugalRadio I have HackRf with 20Mhz bandwidth ,i dont think locked channel dependent to bandwith in this case. presumably the channel is encrypted.

[@FrugalRadio]

Ah, perhaps it is encrypted then. If that's the case, SDRTrunk should display it in a different colour if I'm remembering correctly. Lots of the P25 around here is Enc.

[@dimmoos757]

@@FrugalRadio Is there any program to decrypting that? i need software same SDRangel to transmission in DMR mode... do you know any that?

[@FrugalRadio]

No, P25 digital encryption cannot be monitored. I haven't used SDRs for transmitting, so can't offer any suggestions for that.

[@chasesambell369]

What hardware is needed to use Unitrunker?

[@FrugalRadio]

This video was made with version 1 of Unitrunker. It runs well on old computer hardware. I've been using an old laptop for many years. Version 2 is now released, but it requires Windows 8 or later. You'll also need a basic SDR. A generic RTL-SDR device will work, although my recommendation is the RTL-SDR v3.

[@windvane_npk5844]

Are there apps that you can use on an android phone?

[@FrugalRadio]

SDR Touch is one that comes to mind. There may be others out there as well.

[@windvane_npk5844]

@@FrugalRadio is there a unitrunker or other app that you can listening to Trunked systems*

[@windvane_npk5844]

Or could you use a tablet? For a mobile listening set up. Plugging two dongles into it?

[@FrugalRadio]

I haven't seen a tablet with 2 dongles, but with 1, yes.

[@joecizin9357]

Very informative 👍

[@FrugalRadio]

Hopefully it will help people understand how these system functions, and give an insight into the kind of data you can receive with an SDR!

[@joecizin9357]

@@FrugalRadio Do both setups require 2 RTL-Sdr s ?

[@FrugalRadio]

It depends on the SDRs and the system. You would need 2 if wanting to monitor voice, and the system has channels spread out over more than 2 MHz. The SDRTrunk footage was shot using only 1 SDR, but the AirSpy R2 has around 10 MHz bandwidth. There's a little more detail at my blog : frugalradio.com/unitrunker-sdrtrunk-demonstrated/

[@joecizin9357]

@@FrugalRadio Thanks

[@FrugalRadio]

You're welcome 😄

[@85Studios]

"This section or feature (P25 Channel ID Tables) is available only to Premium Subscribers" going to have to get it somewhere else. Radioreference has become greedy and wants you to pay to be able to see the channel ID list

[@daklakdigital3691]

Over and Out? It's either one or the other except on TV, videos or dummies.

[@FrugalRadio]

Yes, I know. I get comments about it all the time! But KZbin is TV, right?