SDRTrunk RTL-SDR P25 P1 Hearing Unintended Traffic From Another City

[PilotJoshua]

If I listen to the control frequency I don't hear anything but listening to "alt control 2" I start hearing audio. I'm also hearing traffic and seeing talkgroups from a neighboring city but those aren't even part of the talkgroup aliases I imported from RR? I'm using an RTL-SDR V3 + RTL-SDR V4 with a nooelec RaTLSnake M6 antenna.

 

[C_615]

It looks like you are monitoring the Miami P25 system. Certain talkgroups from the Hialeah and Miami Beach P25 systems are also transmitted on the Miami P25 system. I assume that’s for interoperability purposes. I am not sure why those talkgroups are not also listed in the database for Miami P25. It results in you having to manually add them to your radio or SDR software.

 

[dave3825]

If I listen to the control frequency I don't hear anything but listening to "alt control 2" I start hearing audio.

Looks like when you downloaded the system you selected it to configure for each freq.







If you had selected Single, it would have made one site (one entry) in the channels tab and it would rotate to an active control channel. I believe the way you have it now, if the cc changes, it has nothing to advance to which could leave your SDRTrunk sitting idle. You also would not have to keep starting controls channels until you find an active one. It would do it automatically.





Also, what dongle(s) are you using and how many do you have?

 

[PilotJoshua]

Looks like when you downloaded the system you selected it to configure for each freq.
View attachment 171062

View attachment 171064




If you had selected Single, it would have made one site (one entry) in the channels tab and it would rotate to an active control channel. I believe the way you have it now, if the cc changes, it has nothing to advance to which could leave your SDRTrunk sitting idle. You also would not have to keep starting controls channels until you find an active one. It would do it automatically.

View attachment 171063



Also, what dongle(s) are you using and how many do you have?

Looks like when you downloaded the system you selected it to configure for each freq.
View attachment 171062

View attachment 171064




If you had selected Single, it would have made one site (one entry) in the channels tab and it would rotate to an active control channel. I believe the way you have it now, if the cc changes, it has nothing to advance to which could leave your SDRTrunk sitting idle. You also would not have to keep starting controls channels until you find an active one. It would do it automatically.

View attachment 171063



Also, what dongle(s) are you using and how many do you have?

Im using 2, an RTL-SDR V3 and a RTL-SDR V4

 

[dave3825]

Im using 2, an RTL-SDR V3 and a RTL-SDR V4

Ok

 

[C_615]

Im using 2, an RTL-SDR V3 and a RTL-SDR V4

A single Airspy R2 does a fantastic job on that system.

 

[PilotJoshua]

Ok

Ok I was able to set it up to rotate to an active control channel. Instead of importing all talkgroups I tried importing only the ones I care about from Hialeah but I still hear the ones from the neighboring city (Miami). Not sure if there is a way to mute these talkgroups? I can see that TGID on my SDS100 and found patch TGIDs on RR that are close (Ex: 65135)

 

[dave3825]

The system you listen to has tg's up to 3301. If all the unwanted tg's from the other system come in form of a 65xxx tgid, you should be able to set up a tg range from where they start to 65535 and set its audio to mute. I went 65301 to 65535 because that's where mine started.

 

[PilotJoshua]

Thanks everyone I was able to mute them.