Unitrunker and P25

[chief21]

Recently started monitoring a local P25 system with Unitrunker 1.0.32.7 and a RTL2832 dongle. I noticed that the line for the system control channel always displays 65536 in the Target column. I don't recall seeing this with other systems I have monitored.

In addition, from time to time there will be a rapid-fire run of 65536 entries in the Call History, sometimes enough to fill the entire window. I also haven't seen this previously. In an attempt to stop this behavior, I locked out the 65536 group and also checked the "hide" box but it still continues.

Is this an artifact of all P25 systems? If not, what else might I try to stop it?

John

 

[nd5y]

65536 is a fake "talkgroup" that shows up when the CW ID is being sent. When that happens you only see it for a few seconds every 1/2 hour or so. Sometimes it only does it on the lowest frequency and sometimes it does it on all frequencies except the current control channel. It depends on how the system is configured.

Some systems also show 65536 every 1/2 hour but there is no CW ID actually being sent.

I have noticed in the past year or so one multi site system started having a constant 65536 on two of the sites that is there all the time. I don't know what the reason is but I don't think it's a Unitrunker problem. It's real data being sent on the control channel.

I haven't tried locking out and hiding it. If that doesn't work then I don't know if there is anything else you can do about it.

 

[chief21]

Thanks for your comments but this isn't likely a CW ID. It just recently blasted out nearly three full history windows worth of 65536 groups in less than 20 seconds (about 4 groups per second).

John

 

[GTR8000]

Motorola ASTRO 25 systems at system release 7.16 or later broadcast a continuous "Digital ID" BSI (Base Station Identification) on the control channel, as well as on the voice channels while they're active and during the hang time at the end of the transmission. It's transmitted as an integrated part of the normal data stream, it's not an analog CWID.

65536 is a dummy talkgroup ID that Unitrunker uses to represent BSI activity, whether that's an analog CWID on the BSI channel, or the newer "Digital ID"

 

[chief21]

If that is the case, is there any way to prevent TG 65536 from being displayed and logged without affecting other talkgroups?

John

 

[SCPD]

I think this was fixed in the 1.0.33.6 preview.

 

[chief21]

Per the last suggestion, I removed an earlier version of UT and installed the 1.0.33.6 preview... but I am still seeing sustained bursts of TG 65536. According to the history window, these bursts occur at a rate of 3-4 entries per second. Some bursts contain 15 to 25 entries while others contain perhaps 50 to 100 entries.

I've also noticed that the 65536 talkgroup ID displays constantly in the target column, on the control channel line of the main display. When the bursts occur, the talkgroup ID jumps erratically between the control channel and the voice channel on the second line above the control channel.

GTR8000 explained what and why they exist, but I'd like to know if it is somehow possible to prevent them from logging or displaying. Thanks.

John

 

[nd5y]

Per the last suggestion, I removed an earlier version of UT and installed the 1.0.33.6 preview... but I am still seeing sustained bursts of TG 65536. According to the history window, these bursts occur at a rate of 3-4 entries per second. Some bursts contain 15 to 25 entries while others contain perhaps 50 to 100 entries.

I've also noticed that the 65536 talkgroup ID displays constantly in the target column, on the control channel line of the main display. When the bursts occur, the talkgroup ID jumps erratically between the control channel and the voice channel on the second line above the control channel.

Same here, I think, but the system I see this on is 90 miles away and I can't receive it all the time.

 

[WyoWabbit]

Use Pro96Com version 1.11.6, lol - Tom

 

[nd5y]

Pro96Com doesn't work with discriminator audio.

 

[BenScan]

Any chance this talkgroup's(65536) data being on the control channel constantly is making it even harder for Uniden scanners to work properly. I just noticed that the 65536 talkgroup is constantly on the control channel frequencies of the Fort Worth Radio System sites. I know something has changed recently that has made it more difficult to get good reception with the Uniden scanners. In the past, I would see 65536 pop up and fade away quickly on other voice channels. I don't recall noticing it on the control channels until recently, if my memory is correct.

 

[usswood]

Any chance this talkgroup's(65536) data being on the control channel constantly is making it even harder for Uniden scanners to work properly. I just noticed that the 65536 talkgroup is constantly on the control channel frequencies of the Fort Worth Radio System sites. I know something has changed recently that has made it more difficult to get good reception with the Uniden scanners. In the past, I would see 65536 pop up and fade away quickly on other voice channels. I don't recall noticing it on the control channels until recently, if my memory is correct.

TG 65636 is the station ID of the repeater