Airspy and Unitrunker

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jaellio

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Can anyone direct to a help screen that will assist me with the following problem.
Unitrunker wont start Airspy. Now it did yesterday , but not today.
SDR# starts ok with Airspy but not Unitrunker. Is there a setting that I have put in Unitrunker that is preventing the start ??. Infact I have tried two airspy units with no success, which leads me to the thought that its a problem with Unitrunker.. Any thoughts ??.
 

KevinC

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I moved your question to this forum for better visibility.
 

vince48

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Jaellio
make sure on the VCO tab that you have the Airspy serial number chosen or else it will not start.

vince48
 

jaellio

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Airsply and Unitrunker

Thanks Vince you have solved the problem. Now I'm seeing action on the screen.
1. Any training information on Groups/Users etc, I need to understand a little more of what I am seeing on the screen.
 

br0adband

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Groups are the actual talkgroups used for communication, like Police 1 or whatever (what in the old days we'd refer to as a "channel") and are generally referred to by TGID (talkgroup ID) aka the 4 or 5 digit number that identifies and differentiates the talkgroups from each other (which you can then alphatag with modern scanners and software).

Users are the actual radio units used to make the transmissions to the talkgroups and are generally referred to as RIDs (radio IDs). You'll find that the Users list will eventually grow to be considerably large as most systems do end up having hundreds if not thousands of radios in use: handhelds, vehicles, in offices or emergency operations centers (EOC), and so on.

Making an assumption here but most people in this hobby will probably be more concerned with labeling the talkgroups/TGIDs than radio IDs/RIDs but some of us like to try and label the radio units when possible. Through a lot of monitoring I've been able to label a few hundred units here in the Las Vegas area so when I use Unitrunker I'll see not only the talkgroup where activity is happening but I also have a lot of individual RIDs in place as well.

Sometimes those change because radios are swapped out or used by different units, individuals. etc. or they're just tied to different situations. One example is that a radio mounted inside a unit known as Rescue 44 (the radio in the actual vehicle) obviously has one RID but then the handheld unit the EMTs carry with them on a call outside the vehicle will be known as Mobile Rescue 44 and so whenever I can (and have) identify the radios in such ways I just update the User entry for the given RID.

Fun stuff but yes it can take a lot of time to accomplish and of course as noted radios, especially the handheld units, can be moved around in a department so they may change their roles in some situations. Vehicle mounted radios rarely ever change RIDs except in some circumstances like accidents or damage which requires them to be swapped out.

EDIT:
A picture is worth a 1,000 words they say so...

Here's a screenshot of what I typically see on my setup with a breakdown of what's being represented:



Obviously I've customized my Unitrunker setup as I like it: Police/LEO traffic is in blue, Fire/EMS is in red, hospital/trauma is in pink, airport/aviation stuff is in gold, medical transport/Careflight is in orange, etc. Dispatch RIDs are always labeled yellow and pretty easy to identify since those are probably the most popular RIDs in use on any given system.

The top section shows the actual transmission activity going on: the primary control channel for this system is in red (854.4125), the secondary in gold-yellow (854.7125) leaving 12 other frequencies available for actual traffic at any given time. When I snapped this shot there were 4 in use, the one highlighted in green (on the left) is the actual one I'm listening to (LCN 208, 856.2125) and as the communications hops around the green highlight shows me what's actively being monitored. "Audience" is the talkgroup the transmission is being broadcast over/to, "Source Label" is the actual radio unit doing the transmitting, and you can see the Target (TGID) and source (RID) info as well which I then labeled myself.

The bottom section shows what's actually going on "behind the scenes" of the system itself: Joins are when a radio unit is connected/switched to a given talkgroup, Logout is when the radio leaves the talkgroup. Call is when a transmission is being sent from a given radio unit to a given talkgroup. The transmission I'm listening to with Rescue 33 is a long one as the EMT in the ambulance was giving patient vitals to the hospital ER they're going to - because it is a long transmission that's why you don't see it on the bottom portion of the window. It's there in the list but it scrolled off the screen as so many other activities are going on.

The priority of given talkgroups is 50 by default and I rarely alter it, instead I prefer to just lockout (hence the LO in the R column) for that one talkgroup which is the Clark County School District Police Southwest district - I don't particularly care much about what school police are doing so I lock that group out and never actually hear it.

Unitrunker remains one of the single coolest and most useful pieces of software I've ever encountered and it's customizable like crazy, it just takes time and effort to learn how to use it. As seen above, adding the visual aspect to scanning makes it a bit easier to know what's going on even if you're still limited to actually hearing just one thing at a time. I can hold on a talkgroup (thanks for that addition, Rick!), or skip amongst them using the Voice receiver window control (a separate window). Once you do get it working well for your given monitoring setup, it's pretty tough to beat.
 
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jaellio

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Appreciate your advice and thanks, you have helped me with some of the terminology. I notice where you have a "R" in your top database (LCN Database ?), I have a "T" .
 

jaellio

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This is probably the most helpful site that I've belonged to. I'm not one to bother anyone when I can find the information in a manual BUT still looking for the manual on all sections of unitrunker, so again with another question.
How do I determine which channels are unencrypted P25 mode and to listen to this channel (after I've conquered Virtual cable and DSD ?) Do I click on the a line on the users tab. I assuming that all signals are not Voice , but pagers etc etc...
 

br0adband

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There really isn't a formal all-in-one manual for Unitrunker, but there's a few places you can get more instructional info and they're linked from the homepage of the program itself right at the top (the user guide and the summary). If you've got questions you're welcome to ask and if I/we here at RR can help we typically will.

EDIT:

Unitrunker itself tells you if a P25 talkgroup is encrypted (not that I'm aware of) with a "P" in the Svc column (I didn't realize this because I don't get much P25 traffic so I was mistaken hence this edited post). For more info on the Svc codes you can check here:

http://wiki.radioreference.com/index.php/UniTrunker

DSD+ will because that's what you'll end up using for the actual decoding purposes. As for pager and other types of traffic content, realize that radio signals are just radio signals - how they're modulated and what content they carry can be one of many different things. Voice traffic does still tend to make up the majority of the content but the sheer amount of digital content is increasing as more and more communications move to the more efficient formats (they use less bandwidth, etc).
 
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jaellio

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Airsply + Unitrunker + VC + DSD + Headache

Who said it was Addictive ??. ADDICTIVE. I spent 3 night and my aim to decode a P25 signal is ZERO .
Between Airspy, Unitrunker, Virtual cable, and DSD+ i'm a jungle without a road map.

Ah I suppose being 70 years old , my wife will never say "Darling are you coming to bed now ". So I'll press on for another few hours.
 

br0adband

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The biggest downside to most of this stuff, especially for someone that's new to the SDR-based way of doing things 'cause it sure as hell ain't nothing like just punching a few buttons on a scanner to get something working, is that it actually does require some effort. The other problem is there's a bunch of separate applications/programs/tools that all need to be set up and functional on their own before you can even get to the point of trying to make them work with each other in tandem to accomplish just the one task: tuning in a radio signal that is either carrying analog (easy) or digital (the tough nut to crack) content which needs to be decoded for "the good stuff."

It's not impossible, no, just daunting and yet another problem crops up: there's no one single source for the info needed to get all of it working together. Sure, if you do a search here or using any major search engine for "sdr p25 decoding" or something similar you're going to find a bunch of guides written by a variety of people using a variety of software applications and programs and a variety of SDR hardware that somehow magically ends up getting the actual task of actually allowing you to monitor communications. It's a true miracle most of this stuff works at all, sometimes. ;)

Having said that the basic workflow with the hardware and software you've got would be like this using the concept of a signal pathway:

Antenna attached to the SDR device (in your case, Airspy) for receiving a signal feeds the signal to Airspy which is controlled by an SDR application/program to tune in a given signal on a given frequency (or frequencies given the working bandwidth of such hardware) using a given modulation which is then fed from the SDR software application as either:

Analog (which can be and typically is filtered and not a baseband signal) in which case it's sent directly to the sound card for playback through the computer's sound system

or...

Digital which is passed from the SDR application/program (unfiltered basedband for the raw signal) to DSD+ (or the original DSD as some folks like to use that even nowadays) by traditionally using a virtual audio cable (so there's no audio processing done on the signal by the Windows audio mixer/EQ/etc) where DSD+ will be able to decode the digital format/protocol and provide a final product of workable intelligible audio a human can understand

Now that's just for straight analog or digital using conventional transmissions on single frequencies. Toss in trunked systems and it gets a bit more complex when using SDR setups:

If it's an analog trunked system, Unitrunker alone can be used to handle all the popular formats available today by decoding the control channel from one frequency and then tuning voice channels as required. It's more efficient to use two SDR devices (unless you own one like Airspy that has a wide enough bandwidth window to receive all the trunking frequencies at the same time as most tend to fall within a ~5 to ~10 MHz window). In either case, you have Unitrunker handling the decode of the control channel and also tuning in voice channels as assigned given talkgroups/priorities/etc. It works rather well, actually, but there's a learning curve as already mentioned and no seriously great documentation for it although there's a user guide that covers some of the most relevant stuff.

If it's a digital trunked system using any of the popular formats/protocols then Unitrunker can handle the control channel decoding for all the ones in use today but obviously it can't decode the voice traffic which is where again DSD+ comes into play. If it's a P25 Phase I based system - I mention that because it's the most popular format/protocol in use worldwide - DSD+ can handle it easily. There are no software-based decoders yet for Windows that can decode P25 Phase II but we're all hoping that the developers of DSD+ may add it in some future update if possible. If you actually need to decode a P25 Phase II system for voice traffic, assuming it's not encrypted, there's OP25 but that's a Linux-based GNURadio-based software application and somewhat "labor intensive" to get installed properly as it does require some compiling and command line magic so most folks won't go that route unless they have absolutely no other alternatives i.e. a physical scanner capable of P25 Phase II decoding.

But with Unitrunker + DSD+ you can readily monitor most any non-encrypted trunked system in use today given the lack of P25 Phase II voice decoding - Unitrunker can decode a P25 Phase II control channel so at least you'd be able to see what's going on in terms of talkgroup activity/radio IDs, but you won't be able to listen in because of the lack of DSD+ support for P25 Phase II.

I know, I know, more babbling on my part, maybe someday I should just write a damned book on all this stuff and make it dead stupid simple for anybody to get it working. There's two books about RTL-SDR hardware out now, one of them is not quite so easy to grasp for a newcomer to SDR and the other is just a collection of a bunch of articles compiled from postings at the RTL-SDR.com website so it too can be a bit tough to get a handle on since the language isn't tailored for newcomers: both books work on the assumption that someone has at least some basic understanding of radio and communications technology but they're worth considering I suppose.

My advice is do things in steps: start with the simple stuff (literally) and verify your Airspy or whatever SDR hardware device you're using is working as designed, testing it out with a variety of signals and modulations and learning what you can about the SDR application or program you're using to control Airspy. Then start adding additional capabilities by using Unitrunker, DSD+, virtual audio cables, and so on.

If what you're aiming for is a P25 Phase I system, you can do that with Airspy + Unitrunker + DSD+ easier than you might think at this point. In fact, when you do get it working (which you will as long as you don't give up on it because of frustration - been there, done that, almost planted one of my RTL sticks in a wall over it) you'll get that "AHA!" moment when everything comes together and you hear what you've been trying to listen to for what seems to have been an eternity of tinkering around with all of the patchwork stuff. It'll be worth it when that moment comes. ;)
 

jaellio

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"If what you're aiming for is a P25 Phase I system, you can do that with Airspy + Unitrunker + DSD+"

So you don't need virtual cable in this setup ??.
 

Voyager

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The virtual cable is needed so you can keep the voice separate from the data.
 

br0adband

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Yah, my mistake there leaving it out of the signal chain, sorry. And as Voyager noted, that's the purpose for using a virtual cable - the analog voice audio (if you have any systems using it) will be passed to the PC's speakers but digital content needs to be routed to the virtual audio cable to pass to DSD+. It's set up that way so you don't get blasted by those digital formats from the speakers when they come along because on some systems you can have hybrid activity with analog and digital comms.
 

jaellio

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Been reading through the DSD setup and there seems quite a few files to edit , frequencies, groups, networks , radios and sites. Do these all have to be edited ?. or will DSD+ just take what the Virtual cable sends it & decode ?.
 

br0adband

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The files you're referring to are tied to using FMP which is the "SDR" application now included with DSD+ for controlling devices like Airspy and RTL-based sticks iirc and not specifically of any real use if you're using DSD+ only for the purpose of decoding a digital format provided by some other software, in your case Unitrunker. FMP as I understand it is quite powerful for what it is (a command line SDR app, basically) but does offer a simplistic interface while requiring you to edit the config files to make it truly useful.

If your intention is to use Airspy with Unitrunker (routed by virtual audio cable) to monitor that P25 Phase I system, the only thing you'll need for DSD+ is a single command line to do the encoding and it can be as simple as this:

Code:
dsdplus.exe -f1

and that's it - that line fires up DSD+ using defaults and tells it to look for and decode only P25 Phase I traffic fed to it across the virtual audio cable from Unitrunker controlling Airspy (again, in your specific setup). Because Unitrunker would be what's responsible for decoding the control channel, tuning the voice channels, and then providing you with the talkgroup/radio ID/etc information, DSD+ fulfills the role of just being the voice decoder - FMP and those config files aren't necessary in this type of situation.

Of course you can do more with it and add more parameters, name output audio files, and so on, but the line above will get the job done all by itself as long as there's a workable signal being fed to DSD+ to work with.
 

jaellio

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WELL I may respectively ask, what does. Mr Broadband answer was in respect of the command line for only receiving P25 traffic not if the virtual cable is used.
 

br0adband

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If you have things set up properly meaning you have the virtual audio cable installed and you set it as the default Recording device in the Windows audio mixer then yes, it will do exactly what it's supposed to do: DSD+ is "smart enough" to pick the correct input from the virtual audio cable output (because you set it to be the default device).

I know a lot of people make things a lot more complex than they have to be and use rather extensive command line switches with DSD+ but I personally don't: I use DSD+ with that exact line I mentioned above to decode P25 traffic fed to it by virtual cable and have never had to use anything else. I'm not saying you can't use a lot more of the options on the command line, sure, I'm just saying it's not nearly as complicated as some would believe.

Even when using Unitrunker to provide the P25 voice channel data to the virtual audio cable I still use the same command and nothing more, but that's my setup, can't say everyone else likes things that simple I suppose.
 

slicerwizard

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If you have things set up properly meaning you have the virtual audio cable installed and you set it as the default Recording device in the Windows audio mixer

Hm. What does that do to apps that use the microphone? Like, say, Skype? Pretty sure they default to using the default device. Doesn't sound like a good idea to be sabotaging those apps. Maybe you don't use them, but a warning to others might be in order.
 
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