Interested in SDR but very confused

cfsimmont

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I have used many scanners over the years, conventional, analog and digital trunked, handheld and base, Uniden, GRE, & RS but the idea of a scanner on my laptop is something I haven't ventured into but the idea is interesting. I read the wiki page on here about SDR, and a few posts but im still lost. I have heard that SDR is less prone to simulcast issues, is this true? I would mainly be wanting to monitor Phase 1 & 2 P25 systems (no NXDN, DMR, or Provoice). From what I read I would need two dongles to monitor trunked systems? Is there any specific brands that are good vs others, or ones to stay away from that have issues? I am not needing to record any radio traffic or stream at this time, just monitor live radio traffic. Program recommendations for a cheap budget?
 

Markb

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SDR is worth jumping into. You might lose the portability of a handheld or mobile scanner, but for likely well under $100, you can have a very effective setup.
They do function much better than a scanner (Uniden SDS series being an exception).
I would start with an RTLSDR or 2. They are inexpensive and will do fine on a P25 system.
Either Nooelec:



or RTLSDR blog units:


are the 2 main higher quality dongles out there.

I prefer DSDPlus (paid Fastlane version) for monitoring. There are a couple of other software programs out there that people will likely recommend and I am sure they are good as well. Unitrunker is a great option, too with a nice UI.

If you decide to move forward, make sure you have a decent antenna and the appropriate cable and connectors. Also, I would highly suggest spending time on YouTube and find a tutorial or 2. There are plenty out there.

Mark
 

cfsimmont

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SDR is worth jumping into. You might lose the portability of a handheld or mobile scanner, but for likely well under $100, you can have a very effective setup.
They do function much better than a scanner (Uniden SDS series being an exception).
I would start with an RTLSDR or 2. They are inexpensive and will do fine on a P25 system.
Either Nooelec:



or RTLSDR blog units:


are the 2 main higher quality dongles out there.

I prefer DSDPlus (paid Fastlane version) for monitoring. There are a couple of other software programs out there that people will likely recommend and I am sure they are good as well. Unitrunker is a great option, too with a nice UI.

If you decide to move forward, make sure you have a decent antenna and the appropriate cable and connectors. Also, I would highly suggest spending time on YouTube and find a tutorial or 2. There are plenty out there.

Mark
With either of these are two required for monitoring a trunked system?
 

silberj

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It really depends on the range of frequencies in the trunked system you're planning on monitoring. Most dongles (I use the nooelectric ones) have bandwidth limitation that depends on the frequencies with just one, but, they are very inexpensive, and two will likely cover it all. Also the software mentioned above is good, have used it, but I happen to be preferential to SDTrunk, which is java based, so therefore crossplatform and decodes P25 natively (no need to run both DSD+and Unitrunker together), all that's required is a jmbe library which can be downloaded and installed from within the program. It has a super nice interface and is relatively easy to set up. I'm currently using the A2, which even though is alpha, is working like a champ.

 

carnch

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+1 for SDRTrunk. I use it with an Airspy to monitor two P25 Phase1 systems simultaneously and I stream them using free IceCast so I can listen anywhere. The Airspy is a bit more expensive but covers a 10Mhz span (versus 2.4Mhz of most of the cheaper dongles) and both systems that I monitor fall within the a singe 10Mhz range. I do have two of the silver RTL-SDR dongles that I have used in the past and they seem to work pretty well but I found that with only one I was missing some of the conversations so I went to two and used that until I got the Airspy.
 

Markb

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...and decodes P25 natively (no need to run both DSD+and Unitrunker together).......

FWIW, DSDPlus decodes/follows P25 conventional and phase I/II trunking. Unitrunker decodes P25 phase I natively as well. Phase II? Yeah, you need both.
 

cfsimmont

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Ok i bought a SDR dongle (nooelec) and installed SDRtrunk 0.4.0 and installed the jmbe library hopefully to the right directory. In the sdrtrunk I do get the the waterfall screen with peeks on different frequencies but no hits on the Phase 1 system that I am trying to monitor. I am sure I just don't have something setup right, but not sure what it is. I have tried watching the youtube videos but haven't found any that actually walk you through the setup with voice directions, all have annoying music that plays instead.
 

KR0SIV

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SDRTrunk works great for phase1 and II, I've not tried DMR but DSDPlus Fastlane does DMR quite well.
 

cfsimmont

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SDRTrunk works great for phase1 and II, I've not tried DMR but DSDPlus Fastlane does DMR quite well.
I'm trying to monitor a Phase 1 system but can't seem to make it work. I downloaded the newest Java update and I'm going to reinstall SDR trunk and see if I can figure it out
 

KR0SIV

Sarah Rose She/Her
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I'm trying to monitor a Phase 1 system but can't seem to make it work. I downloaded the newest Java update and I'm going to reinstall SDR trunk and see if I can figure it out
Java is now self-contained with the software. No need to download it, what kind of errors are you running into?
I just made a new video on setting up a phase 1 system with it and didn't have any issues.
I'm running the latest alpha (video releases Tuesday)
 

cfsimmont

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Java is now self-contained with the software. No need to download it, what kind of errors are you running into?
I just made a new video on setting up a phase 1 system with it and didn't have any issues.
I'm running the latest alpha (video releases Tuesday)
Over the weekend I downloaded the Alpha 2 of 0.5.0 and wow what a difference, no longer have to download the library separately and select the correct path, all done within SDRtrunk. I kept working at it after many hours of pulling my hair and got it to work with my local Phase 1 simulcast system and i must say a $20 dongle and the free software is a pretty good working setup. There are a couple of things I have yet to figure out.... I setup separate aliases for each department on the system, however when I set one alias to play all of the un-encrypted talk groups play not just the ones in the selected alias. Also trying to see if it can be done, but holding on a specific talk group, versus just scanning the list.
 

rlmurray56

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There is no “hold” functionality in SDRTrunk. There is also a Google Groups support site for the software.
 

bobruzzo

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I have used many scanners over the years, conventional, analog and digital trunked, handheld and base, Uniden, GRE, & RS but the idea of a scanner on my laptop is something I haven't ventured into but the idea is interesting. I read the wiki page on here about SDR, and a few posts but im still lost. I have heard that SDR is less prone to simulcast issues, is this true? I would mainly be wanting to monitor Phase 1 & 2 P25 systems (no NXDN, DMR, or Provoice). From what I read I would need two dongles to monitor trunked systems? Is there any specific brands that are good vs others, or ones to stay away from that have issues? I am not needing to record any radio traffic or stream at this time, just monitor live radio traffic. Program recommendations for a cheap budget?
I am in exact same boat. I want to get into SDR but I am too overwhelmed by the information out there. I need solid advice on affordable dongle for monitoring the same system as you. Not interested in HF at the moment. I just want to be able to listen to the P25 system in my area and maybe a motorola system or two.
 

boatbod

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I am in exact same boat. I want to get into SDR but I am too overwhelmed by the information out there. I need solid advice on affordable dongle for monitoring the same system as you. Not interested in HF at the moment. I just want to be able to listen to the P25 system in my area and maybe a motorola system or two.
If you want to run a RPi4 or other Linux based system, op25 can do P25 and Motorola Type II. If you prefer to work with Windows, you should probably look at DSD+ Fastlane.
 

bobruzzo

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If you want to run a RPi4 or other Linux based system, op25 can do P25 and Motorola Type II. If you prefer to work with Windows, you should probably look at DSD+ Fastlane.
OK I have read everything above and I am still very unclear about how this whole sdr works. I watched some videos but still not getting what I need to get. I have both Linux and Windows. I will more than likely use Windows 10 for sdr cause my radio desk computer has Win10.
To start, all I really want to listen to is my local P25 simulcast system. And there is a Motorola 800mhz trunked system I like to listen to as well....just those 2 systems. I understand I need an antenna so could I use the yagi I am using now with an sma adapter to fit whatever "dongle" I need to get? I dont think a tiny indoor antenna will work. And as far as software, the only software I remember is "Airspy" but I messed with it a few years ago and couldnt get it to do anything. I later found out I need a "dongle".
So step 1 is to GET PROPER DONGLE for P25 / Motorola. Step 2 Get proper software and help setting it up. In the future I may want to check out HF but not right now. I have been spinning my wheels getting nowhere cause I don't know what hardware/software I need. The information on Youtube and on here is too overwhelming and not specific enough for what I want to do.
 
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