Problem with hearing a talkgroup where there are subscriber units affiliated on a site w/ talkgroup

[willie319]

This is a problem I have been having for a while… I have been monitoring a P25 system for over 10 years. With advanced knowledge regarding the system’s operation, and the programming of both radios and scanners for 2 decades.

I have not been able to hear a talkgroup on said P25 system from my home from a scanner, which I know for a fact is affiliated to a site not far from my home which I hear other traffic on. So I know the reception is good to that tower for me. (As well as a legit subscriber radio with an ID).

The talkgroup is audible when I’m in the county it is set up for. (Adjacent to me). And I have a subscriber radio that is affiliated to the local tower to me that is not within the county it is normally used in.

The subscriber radio is able to receive the audio like normal from the local tower on the talkgroup. But my scanner is not able to hear the audio nor does my scanner react to it. (Even though it hears plenty of other traffic on the same tower/control channel.)

What is going on here?

Why does the subscriber unit affiliate and operate normally, but the scanner does not hear it unless specifically in the origin county and near the site?

No, it is not encrypted. I have checked my programming many times, and I have confirmed it works only on the other tower in the origin country.

 

[buddrousa]

The question is how you know that you subscriber radio is affiliated with the tower in the other county?
Does you radio have a feature that shows you what tower it is connected to?
Are you sure you are not connected to the tower in your county?

 

[K9KLC]

Did you program the radio it's receiving it on or, did someone else program it?

 

[MTS2000des]

Is it a TDMA subscriber affiliating on a DDM talk group? If so, and your scanner is FDMA only, you won't hear the SU on the TG.

 

[willie319]

The question is how you know that you subscriber radio is affiliated with the tower in the other county?
Does you radio have a feature that shows you what tower it is connected to?
Are you sure you are not connected to the tower in your county?

Right, it has the site scan option and shows the site it’s connected to.

The scanner has the CC frequencies put in a scanning bank and is “allegedly” properly configured for that trunking system. And set up for that talkgroup.

Did you program the radio it's receiving it on or, did someone else program it?

I did not program the subscriber unit.

Is it a TDMA subscriber affiliating on a DDM talk group? If so, and your scanner is FDMA only, you won't hear the SU on the TG.

This slipped my mind entirely. I think you may have hit the nail on the head. There’s only a few subscriber units on the tower I am trying to listen to, versus hundreds on the origin county for the TG.

 

[MTS2000des]

This slipped my mind entirely. I think you may have hit the nail on the head. There’s only a few subscriber units on the tower I am trying to listen to, versus hundreds on the origin county for the TG.

Is your scanner TDMA capable?

 

[willie319]

Is your scanner TDMA capable?

Nope, it is not. That answers the question.

It didn’t cross my mind that due to low amount of subscribers, the scanner won’t pick up the TDMA/phase 2 transmissions.

But on the origin site, there’s subscribers that are older. Makes sense now.

Thank you everybody.

 

[IC-R20]

Advanced knowledge regarding operation

Doesn’t realize it had phase 2 talkgroups 🤣

 

[willie319]

Advanced knowledge regarding operation

Doesn’t realize it had phase 2 talkgroups 🤣

I think you should read the replies I made and understand my reasoning. Talk group works on site A with my scanner. Talk group does not work on site B with my scanner. But my issued XTS4000 works on both.

Sh•••y comments like yours makes people not want to participate on forums.

 

[mmckenna]

But my issued XTS4000 works on both.

That adds to the confusion.
The XTS4000 is not P25 Phase 2 capable. If it is a legit radio on the system programmed by the system administrator, and it is working correctly, then the TDMA thing may not be the issue, unless I'm missing something.

The scanner has the CC frequencies put in a scanning bank and is “allegedly” properly configured for that trunking system.

The term "allegedly" becomes the red flag here.

It sounds a lot like something isn't programmed correctly, unless I'm missing something here.

 

[KE4ZNR]

That adds to the confusion.
The XTS4000 is not P25 Phase 2 capable. If it is a legit radio on the system programmed by the system administrator, and it is working correctly, then the TDMA thing may not be the issue, unless I'm missing something.



The term "allegedly" becomes the red flag here.

It sounds a lot like something isn't programmed correctly, unless I'm missing something here.

@mmckenna My guess is he meant an APX 4000 instead of XTS 4000. If so then the APX 4000 is indeed capable of TDMA operation (if it has the option in the FC). Just my half a penny for what it is worth

 

[IC-R20]

That adds to the confusion.
The XTS4000 is not P25 Phase 2 capable. If it is a legit radio on the system programmed by the system administrator, and it is working correctly, then the TDMA thing may not be the issue, unless I'm missing something.



The term "allegedly" becomes the red flag here.

It sounds a lot like something isn't programmed correctly, unless I'm missing something here.

My oh my how the plot thickens...