Decoding Fire & Ambulance MDT data & hospital pages with a $10 SDR Radio

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You don't need much to decode pager traffic - just a frugal Software Defined Radio and some free software. In this video I show how to decode the pages, particularly those used by Emergency Services (Fire & Ambulance / EMT).
These pages are often displayed on Mobile Data Terminals (MDTs).
I used a generic dongle in this video, but I recommend the frequency stabilised units (with TCXO) below :
NooElec SMART : amzn.to/2YKlh6p
RTL-SDR v3 : amzn.to/2NIGGGZ
I used an MCX to BNC adapter for the antenna : amzn.to/3omy3W7
However if you are using an RTL-SDR or NooElec SMART you'll need one of the SMA connectors, such as those in the kits below.
RTL-SDR pigtail kit : amzn.to/3F5Stsf
NooElec SMA connector kit : amzn.to/3jLAXyJ
-- Software Links --
SDR++ : github.com/AlexandreRouma/SDR...
VB Cable : vb-audio.com/Cable/index.htm
PDW : discriminator.nl/pdw/index-en...
-- Other RU-vid videos mentioned --
Pager use by Dr. Siobhan @ViolinMD : • Day in the Life of a D...
SDR++ review by @SignalsEverywhere : • SDR++, The Cross-Platf...
SDR++ review by @TechMindsOfficial : • SDR++ Multi Platform S...
-- Timecode --
00:00 - Introduction
00:52 - Pagers in 2021
02:20 - Pager Users
03:39 - Emergency Service Pages
03:59 - MDTs (Mobile Data Terminals)
04:21 - Decoding Setup
05:57 - Set up SDR++
07:45 - Set up PDW pager decoder
10:36 - Filtering Messages in PDW
12:09 - Understanding Fire & EMS pager messages
14:12 - What can you decode?
Photos of Edmonton Fire Rescue Service vehicles found at www.barp.ca/photo_index2.html, and copyright mike-from-edmonton
As always, thanks for watching the Frugal Radio (FR) channel!

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10 май 2024

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Комментарии : 126

@jj2me 2 года назад

Great video Rob! Thanks for the useful tips on decoding those signals, I've often wondered. Nice seeing you back up and running again too.

@FrugalRadio 2 года назад

Thanks! Let me know what you're able to decode if you decide to give it a try!

@djk8541 2 года назад

I like that your videos open with background information to explain why we may be interested in following the guide

@FrugalRadio 2 года назад

Good to know that's helpful, thanks.

@SignalsEverywhere 2 года назад

Thank you for mentioning and linking to my tutorial, love your channel. Great production value, I like how you put your videos together!

@FrugalRadio 2 года назад

Thanks @SignalsEverywhere. Your channel is part of the reason I got started!

@-_______________________.___ Год назад

@@FrugalRadio Sadly she quit RU-vid 2 days ago :'(

@FrugalRadio Год назад

Oh, I didn't know this.

@someoneintheback5939 2 года назад

Awesome video! Great tutorial! Been wanting to do this with my rtl for a while!

@FrugalRadio 2 года назад

Have fun giving it a go!

@CptnKremmen 9 месяцев назад

Many (20ish) years ago I wired a jack socket to the discriminator on my AR2000 scanner. It's nice to know that SDRs can use a similar trick. I didn't realise that people were still using pagers - I might have to dust if off and use the PDW software (just checked my NAS) I used to use POCSAG Decoder.

@FrugalRadio 9 месяцев назад

Yes, what you will receive will depend on what's in use in your area. But SDRs are way easier than discriminator taps!

@Subgunman 2 месяца назад

Some places still use the older Motorola Golay format. There were paging programs one could load onto older computers but utilized modem cards to dial into the paging transmitters over dedicated DID ( direct inward dialing ) inbound lines to the paging terminals. User could bring up the program and send a page, numeric or alpha, to the specific user.

@EverydayJ1786 2 года назад

Very cool Rob ! . I was not aware of the ability to monitor pager signals in the Edmonton Area 👍

@FrugalRadio 2 года назад

Yep, there's loads of data traveling through the air all around us!

@MrToymod 4 месяца назад

Thankyou Rob , got me up and running, you are a star **. I’ve bought you a coffee as you’ve saved me lots of frustration 😅

@FrugalRadio 3 месяца назад

Appreciate it. Thank you!

@dilushasamarasekara9533 2 года назад

Great video as always...!!!

@FrugalRadio 2 года назад

Thank you 😊

@lizzapaolia959 5 месяцев назад

Fantastic video, God bless 🙏

@FrugalRadio 5 месяцев назад

Thank you! You too!

@R33f4_61 Год назад

Great video... had it up and running in no time. Found 2 systems just above the 2m band. POCSAG/512(Hosp.) & FLEX/1600(Em Serv.)🇦🇺

@FrugalRadio Год назад

Excellent. Well done. What area are you in?

@R33f4_61 Год назад

@@FrugalRadio I'm in Sth Aust. I was hoping to be able to get mdt job dispatch data for emergency services but i haven't had any luck in finding that yet. Not sure it's even possible anymore bcos of newer systems, and encryption ??? (Just getting back into the hobby after a 5yr break)

@FrugalRadio Год назад

There are many ways to send such data now. Some departments use cellular data links, some have their own data link systems, some send data via their P25 system, some use pages, and many are now switching to smartphone & tablet apps.

@R33f4_61 Год назад

@@FrugalRadio There's a local website that has 800Mhz & 1800Mhz RDLAP data frequencies listed but i don't pick up any signals in the 800's. Obsolete??? And I've noticed that police vehicles now have a small thick antennas(about 4inches) so I'm thinking that's probably for a separate data system🤔

@R33f4_61 Год назад

@@FrugalRadio One other thing... how do i go about creating a FMP ScanList ???🤔🤔🤔 I've watched many videos, including yours on sdr# & dsd+, but I'm stuck on that part. The videos I've watched only say to download one from RR which isn't possible. Help in the right direction would be much appreciated.

@sekyuvlog 10 месяцев назад

Nice video, I learn a lot on your video.

@FrugalRadio 10 месяцев назад

Great. Glad it has been helpful.

@thewind-ne8rh 2 года назад

welcome back

@FrugalRadio 2 года назад

Thanks!

@Ztbmrc1 2 месяца назад

Nice video. Interesting what you can still see there in Edmonton, Canada. Here in the Netherlands we have strickt privacy legacy. Besides that the services of fire, ambulance and police changed over to the digital tetra based system (C2000) for their voice communication that we can no longer listen to, they still have a pager network operational (P2000) on 169.65 MHz in Flex 1600 mode. But they are reducing the information there also because of the privacy rules. The police has stopped using the pager system, however they remained sending press messages there. But recently they have decided to stop that too. Btw I just discovered another weaker pager signal next to the P2000 on 169.625. It were messages first in French than also in Dutch. They are from Belgium. It looks like hospital and ambulance services. Did not know about that... It is in POCSAG 2400

@FrugalRadio 2 месяца назад

Thanks for your report on the state of transmissions in NL. Cool that you can receive the Belgian pager signal too. I was traveling in the UK last month. Still saw some Ambulance traffic on the pager networks, as well as general medical info.

@Ztbmrc1 2 месяца назад

@@FrugalRadio Ok. I just found the confirmation that indeed on 169.625 is the Astrid pager system from Belgium. And alle other public pager systems have ceased to exist here in the Netherlands. Just wonder where the hospital pagers here in NL are...

@kenny7479 2 года назад

Great video. I was curious if you had tips on getting a better percentage reading on the top right of PDW? My reading seems to be somewhere around 70 and red.

@FrugalRadio 2 года назад

Hi Kenny. Playing with the audio levels is the key, and making sure your bandwidth is wide enough. There are times I really struggled to get the balance right, especially on certain computers. Other times it works perfectly. A lot of trial & error!

@ManuelPinner 6 месяцев назад

SDR Angel have this Feature available on it!

@skideric 2 года назад

Have done this off & on for years.Mostly with Scanner & PDW Software,easier than using dongle...

@FrugalRadio 2 года назад

My first attempts were with scanners, years before SDRs were so ubiquitous. However I don't like tying up a physical radio when I can use an old SDR that would otherwise be lying around in a drawer! What frequencies & modes are used in your area?

@coondogtheman 5 месяцев назад

I was able to get this working ok with nothing more than my computer, PDW program and a wind up radio that can pick up weather bands and somehow picks up pager traffic. I have an RTL SDR but the reception is crap when I have it hooked to my PC so I use my phone for the SDR with SDR touch and it works well. Can't use that for the pager traffic though. The data I hear sounds just like some of the transmissions heard in the video.

@FrugalRadio 5 месяцев назад

Very interesting. Pager transmitters can be very strong, so they often decode well - but this is the first I've heard of it on a wind up weather radio. That's neat. Thanks for sharing!

@coondogtheman 5 месяцев назад

@@FrugalRadio I don't know where the radio is at the moment but it has this reverse phase simulated stereo which messes up the signal but if I pull the cord out slightly it works. I may have to modify the radio of better yet find another that works.

@alanwallis2796 2 года назад

Hi Rob, thanks for the video, just a quick question, I see you are using SDR ++ do you know of any conflict problems when using the SDR Sharp and SDR Sharp community package with SDR ++ Installed ? I think I saw a post somewhere that the early versions of SDR ++ caused problems ? and SDR Sharp had to be re installed ? It may be that the latest release has solved that problem any thoughts regards Alan

@FrugalRadio 2 года назад

Hi Alan. I hadn't heard anything about that. I have SDR# (an older version) and SDR++ installed on the old laptop that I used to make this video, and didn't encounter any problems. Although I only used SDR# once since installing SDR++.

@tgray04 2 года назад

Interesting video. What is the best way to locate pager frequencies for a particular area? Is it just manually scanning select bands for traffic? What about P25 systems?

@FrugalRadio 2 года назад

You could check out the National Implementation section of the Wikipedia article at en.wikipedia.org/wiki/POCSAG as this gives example frequencies for some countries. For P25, I'm assuming you're in the US. Check 769-775 MHz, and 850-867 MHz initially for trunked P25 systems. You will also find P25 in VHF & UHF public safety / federal bands.

@morejelloplease Год назад

can sdrtrunk do this without having to download the extra decoding program and virtual cable ?

@BenjiNotknown 2 года назад

I have both POCSAG & FLEX here in England, FLEX is much more rare toreceive a message though. I didn't know there was a voice pager frequency though, i'll have to tray that. thanks.

@FrugalRadio 2 года назад

Keep an eye on the waveform in your SDR software. The voice pages are transmitted in amongst all the data. If you have audio routing to PDW you'll often miss it. Sometimes I set a scanner to the pager freq to monitor the voice traffic, but it's frustrating as most of the time you just hear the sound of the data.

@bennguyen1313 2 года назад

Does the Pager decoding software (SDRPlusPLus/PDW) only do POCSAG , FLEX , AUDIO? Or can it be configured for other public/emergency broadcasts like P25/ DSD (LouisErigHere)? For example, I understand for the Inmarsat AERO satellite (1600Mhz) which covers C Channel for air to ground and L-band for ground to air. Medlink voice communications uses (Iridium?) decoding? I believe jontio / libaeroambe built JAERO to decode AMBE compressed audio, but not sure.

@FrugalRadio 2 года назад

PDW can do POCSAG, FLEX and ACARS officially. I've used it only for the first 2 of those. It cannot decode satellite ACARS. For that you definitely want JAERO with AMBE if you want the audio.

@bennguyen1313 2 года назад

@@FrugalRadio Thanks. I've heard OpenEar also shows promise of an all-in-one decoder (TETRA, P25, POCSAG, ADSB, AM, N/WFM)!

@FrugalRadio 2 года назад

Yes, although it can no longer be directly downloaded. I gave it a try, but had greater success with other software.

@LTtaz4067 Год назад

I live in the US, my counties public safty is on P25 band. Your video above is assume and I can't wait to try it. I have a question about video feed. My services send images of things like EKG's (ECG's) over the radio. What do you need to be able to see those?

@FrugalRadio Год назад

I'm not sure. A lot of agencies would send that sort of data by either cellular, or PoC. Here law enforcement distributes images by a secure app on their phones.

@LTtaz4067 Год назад

@@FrugalRadio thank you

@dennisbaker555 2 года назад

I noticed when you entered your receiving frequency that it was one single frequency. I know little to nothing about decoding paging, but I am curious. In my area public safety uses a trunked network, specifically P25 Phase I and P25 Phase II. I would assume that the digital information is sent out on one of the control channels within the trunking network. So, does this device you featured have the ability to monitor multiple frequencies? How would you go about decoding paging on a trunked network?

@FrugalRadio 2 года назад

Data traffic on P25 networks seems to use regular channel assignments on the network. I honestly don't know a way to decode that data. I would assume it is also encrypted.

@dennisbaker555 2 года назад

@@FrugalRadio ok, I’m going to see if I can figure it out. I’m sure there is stand alone trunk tracking software. My assumption is that if voice isn’t encrypted then data won’t be either. But, I could be wrong.

@FrugalRadio 2 года назад

If you are familiar with wireshark, that might be a place to start. SDRTrunk appears to show IP addresses of data connections.

@gage3809 2 года назад

I am tuning into the same frequency since it is fairly active, and it seems that the audio cable is working since in PDW the needle jumps around during broadcasting (not by much though), but there is nothing showing up....any ideas why?

@FrugalRadio 2 года назад

There are a lot of things to check, but they are all covered in the video I think. Make sure your check the first part on how I set up the software. Ensure you're using NFM with a bandwidth similar to what's shown. Also, play around with your volume settings. PDW can be quite finicky when it comes to this. You might want to experiment with your gain levels as well.

@Lordabememes 2 года назад

Can you please make a video about Tetra trunk tracker software and The Tetra demodulator

@FrugalRadio 2 года назад

No, unfortunately I can't. As I'm in North America I have no Tetra systems in use in my area.

@Lordabememes 2 года назад

@@FrugalRadio Ah ok I understand thank you anyway I really enjoy watching your videos

@robertodelavega9311 2 года назад

o tetra e outro plugin. não usa cabo virtual se não estiver criptografado e fácil.

@LTtaz4067 Год назад

Hi Frugal, I have gotten to a point in this sdr journey I have another guesting. I the video about pager, you talk about MDT terminals. I gave to three software I am using at the moment, SDR#, DSD++ Fastlane, and SDR - Trunk. They all are decoding what looks like the information from the MDT, but it goes by really fast. My question is how did you make the pretty monitor to look like a real dispatcher terminal.

@FrugalRadio Год назад

Hi Chris, thanks for your question. I don't get any MDT type data on the P25 system here as it is all encrypted. I can see data transmissions taking place, but no data from them. Not even GPS coordinates. My pager screen is generated by PDW, a free POCSAG / FLEX decoder available online. I use it's filtering capability to display the traffic I'm most interested in on the bottom pane. The top pane shows all the other traffic passing through the system (mainly hospital stuff).

@LTtaz4067 Год назад

@@FrugalRadio I have been having a hard time getting it to work. I set SDR# audio to VRW line out. My PC's is VRW line out, and PDW software to VRW line out. I have played with different volume settings and nothing runs, just loads up. Any ideas.

@FrugalRadio Год назад

If the needle in PDW moves, then it is receiving audio. If the needle doesn't move, no audio is getting through. That's the first thing to check. Then you can check levels. It is also good to check on the parameters of SDR#. Is your bandwidth set to a good value (just beyond the edges of the visible pager signal)? Is the RF gain appropriate? Is it a good, clean signal when you listen through the speakers? Then in PDW ensure that the correct signal format is selected for decode, based on the signal you're receiving. For example if it is set to ACARS, it might not decode pager traffic. Ensure the appropriate baud rates are selected as well. I usually check all the options for that, as some transmitters use multiple baud rates based on the subscriber device.

@LTtaz4067 Год назад

@@FrugalRadio Thank you than was very helpful I will try this.

@cmjx 2 года назад

I receive local pager traffic on FLEX at ~929mhz, and POCSAG at 1200baud - 152.0075 MHz. The latter is less intrusive information. I usually just run: "multimon-ng -a POCSAG512 -a POCSAG1200 -a POCSAG2400 -a FLEX -f alpha" while having SDR++ running to get output in a terminal.

@FrugalRadio 2 года назад

Sounds like you've got it well figured out for your area. That's great. Thanks for sharing.

@cmjx 2 года назад

@@FrugalRadio It's a great video, thanks Frugal Radio!

@FrugalRadio 2 года назад

Thanks for your kind comments 😃

@AntonioFardella 2 года назад

I have a question. I have been told that that 243.000 and 282.8 MHz are emergency frequencies. On paper they should belong to VHF spectrum, but they appear to be the "UHF emergency frequencies". Why is that? Why are they listed in the set of UHF while they evidently belong to VHF spectrum? Thank you for your answer.

@FrugalRadio 2 года назад

The 225-399 MHz range is dedicated to Military Airband frequencies in some countries. Other countries it's up to 380 MHz. This has come to be known as the UHF airband, since the largest part is UHF. You make a good point though. Technically almost half is VHF. But VHF air frequencies is used to refer to the civilian airband (118-136.975).

@AntonioFardella 2 года назад

@@FrugalRadio Thank you for the fast reply. At this point I put aside the mere meaning of "VHF spectrum" and "UHF spectrum" and will rather consider "spectrum for civilian use" and "spectrum for military use". Precious info!!

@tomrous 2 года назад

Quetion for viewers: Is there any pager system commonly used in Europe?

@FrugalRadio 2 года назад

I received both POCSAG & Flex in Europe in 2019. What about other users? As Tom asked, what systems are you picking up?

@ManuelPinner 2 года назад

SDR Angel Software can do this to!

@FrugalRadio 2 года назад

It can decode POCSAG, yes. Can it also do the filtering?

@MrShiffles Год назад

anyone having issues with vb-cable in windows 11? I cant pipe any audio into pdw or dsdplus etc

@TheRifleman336 2 года назад

Sadly since the mid 1990s it's been illegal to decode Pagers, or MDTs for public service here in the US. Get caught and it's either a heavy fine or prison time..... :(

@FrugalRadio 2 года назад

That is unfortunate indeed.

@williamhowell1791 10 месяцев назад

What state do you live in that says this law is true law.... I'm not aware of a FCC rule that states such... It's only illegal to monitor such traffic if one uses it for money gain... or in some states if it's encrypted. Othen than that, the airwaves are open to anyone that wants to listen to them..

@FrugalRadio 10 месяцев назад

I'm in Canada, and I think it is okay to monitor here. But in the UK where I lived for 30 years, you are not allowed to monitor any signals not intended for you.

@kishascape 6 месяцев назад

@@williamhowell1791it's not actually enforced. I used to Livestream decoding all the time years ago and would post the PDW logs online publicly.

@RedLine_Renesis 2 года назад

Remember folks. You could be decoding the last moments of someone's life. You will, one way or another, be part of it.

@FrugalRadio 2 года назад

Certainly a possibility. Although a high percentage of fire service calls are also false alarms!

@williamhowell1791 10 месяцев назад

So what's your point??

@BritishBeachcomber 2 года назад

You can't do that in the UK, where we've been using digital radio, similar to the cellphone network, since 2000.

@FrugalRadio 2 года назад

Actually you can. Several ambulance services are still using pagers for MDT transmission.

@BritishBeachcomber 2 года назад

@@FrugalRadio True, but pagers don't carry much useful information, just alerts.

@MrToymod 4 месяца назад

@@BritishBeachcomberI’ve just had a go in the uk , interesting stuff!!.

@FrugalRadio 4 месяца назад

Yes, surprising what is out there.

@ManuelPinner 5 месяцев назад

Sdr Angel Software have this Feature,

@FrugalRadio 5 месяцев назад

Yes it does. Can it also filter the specific messages you want to see, based on keywords and / or capcodes?

@Domgelina 2 года назад

How come I can't install the slicer driver, it needs a specfic comport nothing works?

@FrugalRadio 2 года назад

No idea. I didn't install any slicers. Just ran the audio via virtual cable. No need for discriminator taps or slicers when using SDRs 🙂

@Domgelina 2 года назад

@@FrugalRadio I got it working now, just had to figure, out my local freq

@FrugalRadio 2 года назад

Excellent news. Perseverance pays off What services are using it in your area, and what frequency are you finding signals on?

@Domgelina 2 года назад

@@FrugalRadio I'm in Ontario 4 hours away fom Toronto, so far i just found one freq- in the 929's, but its from toronto hositpals-- the type says mostly Alpha

@Domgelina 2 года назад

Is their an esier way to look for freq, i have the ranges i need on paper

@Onkel_Daniel 2 года назад

Thanks for the video, but it's nothing for me, our Pocsag is encrypted 😭

@FrugalRadio 2 года назад

Oh, that's a shame. I see some encrypted pages, but they are few and far between. Do you have any idea who the users are, and what frequency / area?

@Onkel_Daniel 2 года назад

@@FrugalRadio German Fire and EMS.. some between 164 and 179 mhz and some around 380-430mhz

@FrugalRadio 2 года назад

Thanks for letting me know @Faolan. It is interesting to hear about the different frequencies and users in each region.

@Onkel_Daniel 2 года назад

@@FrugalRadio im work with SDR since 2016 i mean.. its very nice but the Most frequencies are encrypted, new we have Tetra POL and in a few month we get encrypted Pocsag :( xD

@David-wv7sv Год назад

Terrible Audio, Invest in a cheap mic at least.

@min55r Год назад

Hola, como puedo contactar con usted ? me gustaría poder preguntarle sobre un programa...el precio y como funcionaria...Gracias (soy española traduje este escrito para poder comunicarme con usted) Hello, how can I contact you? I would like to be able to ask you about a program... the price and how it would work... Thank you (I am Spanish, I translated this writing to be able to communicate with you)