Decoding conventional P25 on a computer

[kjl13]

Hey RR,


A buddy of mine has an analog radio that he wants to use to decode a P25 channel for a local government radio system that I listen to.
I have heard of DSD Plus or whatever it is called and I recommended that to him, but, he was not sure/unaware of how to get it working. And I could not point him in the right direction because I personally do not have much experience either.

Furthermore, he is using his analog radio then outputting the audio through a USB cable into his computer that came with the radio.

If anyone is able to give a step by step explanation on getting DSD working, that would be great.
Or, if anyone has any other programs that can decode P25, those would also be great.

And I know this is going to come up:
For those who may recommend an SDR, he is planning on getting on in the future but he is still researching.

Thanks, I am looking forward to your responses,
Kyle

 

[AB9NN]

Hey RR,


A buddy of mine has an analog radio that he wants to use to decode a P25 channel for a local government radio system that I listen to.
I have heard of DSD Plus or whatever it is called and I recommended that to him, but, he was not sure/unaware of how to get it working. And I could not point him in the right direction because I personally do not have much experience either.

Furthermore, he is using his analog radio then outputting the audio through a USB cable into his computer that came with the radio.

If anyone is able to give a step by step explanation on getting DSD working, that would be great.
Or, if anyone has any other programs that can decode P25, those would also be great.

And I know this is going to come up:
For those who may recommend an SDR, he is planning on getting on in the future but he is still researching.

Thanks, I am looking forward to your responses,
Kyle

I use SDRTrunk, newest version, and it works like a charm. I run two RTL-SDRs. I live in Michigan and it is pretty active even though we are in a rural area. That is my go-to software for trunking P25. There is also analog P25 and for that I use DSD+ Fast Lane. It works very well with scan lists which are text files of frequency, mode, description, bandwidth and delay information. I have several modes including regular FM, P25, NXDN and DMR. For FM when it runs across an active ham frequency that is digital it decodes that. System Fusion, for example. Analog scan only needs one dongle and since I have three, one dedicated to HF, I run two instances of DSD+ each running their own scanlists that are different. That way it is effectively twice as fast. I use batch files to control them with shortcuts to start them. In the scanlists I have each one segmented with EOF> inbetween sections of the list that i may want to quickly eliminate. If I change it to <EOF> it then considers that the end of the file, just like old dBase days, and loops back to the top of the scanlist. It is flexible and use of FMP24 is through the text files and scan lists. Hope that helps. It tooks some time to figure out what was what but looking back on it I can see it is a nicely designed system, well laid out and pretty well documented. Like skiing - once you know how to do it - it's pretty simple. There is a learning curve and these forums are wonderful!

 

[kjl13]

I use SDRTrunk, newest version, and it works like a charm. I run two RTL-SDRs. I live in Michigan and it is pretty active even though we are in a rural area. That is my go-to software for trunking P25. There is also analog P25 and for that I use DSD+ Fast Lane. It works very well with scan lists which are text files of frequency, mode, description, bandwidth and delay information. I have several modes including regular FM, P25, NXDN and DMR. For FM when it runs across an active ham frequency that is digital it decodes that. System Fusion, for example. Analog scan only needs one dongle and since I have three, one dedicated to HF, I run two instances of DSD+ each running their own scanlists that are different. That way it is effectively twice as fast. I use batch files to control them with shortcuts to start them. In the scanlists I have each one segmented with EOF> inbetween sections of the list that i may want to quickly eliminate. If I change it to <EOF> it then considers that the end of the file, just like old dBase days, and loops back to the top of the scanlist. It is flexible and use of FMP24 is through the text files and scan lists. Hope that helps. It tooks some time to figure out what was what but looking back on it I can see it is a nicely designed system, well laid out and pretty well documented. Like skiing - once you know how to do it - it's pretty simple. There is a learning curve and these forums are wonderful!

Ok, thank you.

I will forward the message on to him.

 

[kjl13]

I use SDRTrunk, newest version, and it works like a charm. I run two RTL-SDRs. I live in Michigan and it is pretty active even though we are in a rural area. That is my go-to software for trunking P25. There is also analog P25 and for that I use DSD+ Fast Lane. It works very well with scan lists which are text files of frequency, mode, description, bandwidth and delay information. I have several modes including regular FM, P25, NXDN and DMR. For FM when it runs across an active ham frequency that is digital it decodes that. System Fusion, for example. Analog scan only needs one dongle and since I have three, one dedicated to HF, I run two instances of DSD+ each running their own scanlists that are different. That way it is effectively twice as fast. I use batch files to control them with shortcuts to start them. In the scanlists I have each one segmented with EOF> inbetween sections of the list that i may want to quickly eliminate. If I change it to <EOF> it then considers that the end of the file, just like old dBase days, and loops back to the top of the scanlist. It is flexible and use of FMP24 is through the text files and scan lists. Hope that helps. It tooks some time to figure out what was what but looking back on it I can see it is a nicely designed system, well laid out and pretty well documented. Like skiing - once you know how to do it - it's pretty simple. There is a learning curve and these forums are wonderful!

Question, is the DSD+ Fast Lane a separate paid program? And is this the only program that can decode P25?

 

[slicerwizard]

DSD+ 1.101, downloaded from dsdplus.com, will decode conventional P25 traffic.

But for any decoder, you need to feed it flat, unfiltered FM demodulated audio. Is your buddy's radio capable of doing this?

 

[kjl13]

DSD+ 1.101, downloaded from dsdplus.com, will decode conventional P25 traffic.

But for any decoder, you need to feed it flat, unfiltered FM demodulated audio. Is your buddy's radio capable of doing this?

That is what I told him earlier, but I don't really know to much about his radio.

He is using a IC-7100, he is asking if he should use AF or IF for the ACC/USB output select(located in the setting in the radio).

 

[rbrtklamp2]

You could always use the old linux version of he wanted I know that it took audio straight from the disc tap of the radio. But DSDplus or even the windows version of the old version should all do what he needs. The only difference is DSDPlus will give you more digital modes and possibly a better decode rate as well. If hes really looking for a project I have heard good things about OP25 as well. Bottom line do your research and see what best fits your needs and go from there, as there are a bunch of programs out there when it comes to digital voice decoding via computer. And they all run a little different and have different strengths learning a bit about the software you want to use now will save you a lot of headaches down the road.

 

[AB9NN]

Question, is the DSD+ Fast Lane a separate paid program? And is this the only program that can decode P25?

DSD+ is free but DSD+ FastLane is a small paid fee product. I was leary and did not go for the paid version until I read that is probably would solve issues I was dealing with. I am Very satisfied. If radio as source audio is a question others are better able to speak to that. I run RTLSDR dongles around $30 each or so. I think Fast Lane was around $15 or some reasonable amount given the development you see once you get it working and enjoy it. DSD+ Fast Lane will decode FM, P25 both analog and trunked, NXDN, DMR, some digital ham radio, etc.. It will not decode some things like supposedly antiquated EDACS but I think it worth the minimal funds. Fast Lane gets you the latest and greatest version of DSD+ and was well worth it when I opted in for it. I don't have a financial interest in any of these by the way other than the fact that I sent in my money and am glad I did.

 

[kjl13]

DSD+ is free but DSD+ FastLane is a small paid fee product. I was leary and did not go for the paid version until I read that is probably would solve issues I was dealing with. I am Very satisfied. If radio as source audio is a question others are better able to speak to that. I run RTLSDR dongles around $30 each or so. I think Fast Lane was around $15 or some reasonable amount given the development you see once you get it working and enjoy it. DSD+ Fast Lane will decode FM, P25 both analog and trunked, NXDN, DMR, some digital ham radio, etc.. It will not decode some things like supposedly antiquated EDACS but I think it worth the minimal funds. Fast Lane gets you the latest and greatest version of DSD+ and was well worth it when I opted in for it. I don't have a financial interest in any of these by the way other than the fact that I sent in my money and am glad I did.

Ok, thanks.

I think he will be getting a SDR in the near future, so he is probably just going to wait for that.

Have a nice rest of your evening.

 

[slicerwizard]

He is using a IC-7100, he is asking if he should use AF or IF for the ACC/USB output select(located in the setting in the radio).

IF.

 

[kjl13]

IF.

Ok, I will forward this on to him.
Thanks a lot.

 

[slicerwizard]

More info:

You don't have to go to this complex level to use DSD with a IC-7100, you can decode direct from the IC-7100 either via USB AF out or the DATA 2 port using the 9600 pin to the Line in or Mic port on a PC. Just remember to select 9600 in the Connectors menu and FM-D as the mode and away you go. Mike G1ZRN.

 

[kjl13]

More info:

You don't have to go to this complex level to use DSD with a IC-7100, you can decode direct from the IC-7100 either via USB AF out or the DATA 2 port using the 9600 pin to the Line in or Mic port on a PC. Just remember to select 9600 in the Connectors menu and FM-D as the mode and away you go. Mike G1ZRN.

Ah ok, I see.

So basically, all he needs to do is just set the mode as FM-D and keep it as USB AF.

Thanks again for your help, gladly appreciated.

 

[Chibson]

Hey, slicerwizard and everyone who replied on this discussion. I would like to thank you all for helping me out on this problem I had with my IC-7100. I greatly appreciate everyone's input, it finally worked out in the end. Credits to Mike G1ZRN for finding the correct solution and slicerwizard who found the comment.

 

[slicerwizard]

Be sure to grab the DSD+ zip file as well as the DLL bundle. Dump it all in a new folder.

About the only thing you have to do is tell DSD+ what device the flat audio is coming from and what device the voice output goes to. Limiting decoding to P25 only may improve decoding.

DSDPlus -i<sourceDeviceNumber> -o<outputDeviceNumber> -fr