No audio on P25 PII with sdrtrunk

[Seth]

Hi all,

Receiving no audio on transmissions, even though I'm seeing the transmissions in the events log.

Using 2x Nooelec NESDR dongles.  Both are seen by the application.  I setup the channel with the alias list created, control channel set as the frequency, LSM modulation because its a simulcast system.  (https://www.radioreference.com/apps/db/?sid=7846)  Note I know a lot of the talkgroups are encrypted, I'm just looking for the fire dispatch and ops channels which are not.

Can anyone suggest where I might have gone wrong?

Thanks

Seth

[Jim Kovalsky]

Sounds like you didn't create the JMBE library.  It will give you exactly that symptom.

Go to View|User Preferences, then Decoder Library, and there will be an automated option to download and create the library.

Jim

[rlm...@gmail.com]

And...if you DID in fact create the JMBE library, then double check your alias setup on the Playlist Editor, and make sure that the "listen" switch is enabled for the talk group(s) aliases that you want to hear.

Ron

[Seth Ainsley]

(My apologies to Ron as I accidentally emailed him directly when responding to the last message - sorry, new Google Groups user)

Hi Ron, 

Thank you for your reply! Much appreciated on the weekend 🙌

I have indeed created the JMBE library and the application shows it created and loaded.

Further i also have the required talk groups set to 'listen' with priority of 1 in the Alias tab and still no audio comes through on the unencrypted channels.

The strangest thing is that sometimes I do not even see the messages being shown in the log (I.e. when I see a 20 second long message come through on the VFD Dispatch channel, I know it is the dispatch call) - and I am hearing these on a separate, traditional scanner - but sometimes, these messages don't even appear despite me monitoring and having Listen turned on for the talkgroup that message would come through on.

Puzzling! Any further thoughts on this? And thank you again for your time!  Happy to provide any screenshots that may be beneficial.

--
You received this message because you are subscribed to the Google Groups "sdrtrunk" group.
To unsubscribe from this group and stop receiving emails from it, send an email to sdrtrunk+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/sdrtrunk/5417ba56-4cc3-442e-b8a5-2eb5b4956e62n%40googlegroups.com.

[rlm...@gmail.com]

You have double checked your User Preferences--->Audio Settings and verified the correct output device has been selected ?

Are you able to set up and hear a known good system using NBFM or AM  ? Like a weather broadcast or airport tower frequency ?

Screen shots of your settings panels from your playlist editor might be useful, as well as tuners panel, waterfall, and anything else that might be pertinent to audio. 

Are you getting lots of sync loss errors on the main screen "messages" tab ?

[Seth Ainsley]

Hi,

Will share some screenshots shortly.

Yes. Lots of sync errors which I've been suspicious of. What do these errors reflect?

Further testing today- I'm able to hear certain transmissions. I seem to not be able to pickup certain talk groups, and on other groups I'm only able to hear the calls from the units and not the dispatch side of the conversation. 

Very odd...

To view this discussion on the web visit https://groups.google.com/d/msgid/sdrtrunk/18df9a10-0047-499a-807e-334dc6f502fen%40googlegroups.com.

[dave38...@gmail.com]

Lots of sync errors means signal problem. Get locked on cc and open tuners tab and see where you are at. Also try playing with the gain.  If you set it up as phase 2, it was advised in 2019, and could have changed, to set it up as phase 1 even if its phase 2 system. Also, make sure you have the cc and the alternates entered in. Below are a few of my phase 2 systems.

[Seth Ainsley]

Thank you Dave,

I do have it created as P25 phase 1, as I observed when I created it as P25 phase 2, my tuners would just flip from IDLE to FADE and back constantly. No transmissions would be received. 

So at least with P25 phase 1, I'm receiving most transmissions albeit not hearing audio on about 50% of the time.

The only difference in my configuration on that screen was that I only have primary control frequency plugged in, and not the alternates as well.  I will add in the alternates too.

Overall, I'm getting the sense that this is most likely overall a reception issue or configuration issue with the gain or PPM of the dongles?

Cheers for all the help.

To view this discussion on the web visit https://groups.google.com/d/msgid/sdrtrunk/3dd2ee20-d56f-46e3-a293-95377132959bn%40googlegroups.com.

[dave38...@gmail.com]

When you have it running and click on the control channel, and then messages, are you seeing any sync loss?  What kind of antenna are you using and where is it located?

[Seth Ainsley]

Hi Dave,

Yes - I see consistent sync loss messages while watching the message feed for the control channel.

You can see the dongle and antenna I am using in the attached stock photo. It's the inexpensive antenna that comes with the dongle so I presume it's not of supremely high quality. I have them mounted indoors, about 3/4 the way up the wall, close to the door to outside, antenna pointed away from the wall. The supplied cable is too short for them to go outdoors (for a quick test I took the whole setup out on to my patio, just outdoors from where the setup normally sits and noticed no significant improvement).

Any suggestions for a better antenna would be appreciated if you suspect this to be the problem and again your help has been greatly appreciated!

Thanks

Seth

To view this discussion on the web visit https://groups.google.com/d/msgid/sdrtrunk/6dfe3c57-9966-4f78-91a1-5295c3746d00n%40googlegroups.com.

[Seth Ainsley]

Apologies, photo attached 

[dave38...@gmail.com]

Those type of antennas never worked for me and I hate mcx connectors so much that I changed them to sma on my cheap china dongles a while back.  Do you have the option for an outside antenna on the roof or a mag mount out the window on an ac unit? What freq range do you mostly listen to? Always best to have an antenna tuned for what you want to receive.