Cap Plus system giving false TGIDs

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NCFireman11

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I am trying to monitor the following MotoTRBO Cap Plus system:

ULS License - Industrial/Business Pool, Conventional License - WQXN876 - Winston Salem State University

I've already figured the LCN (or at least I think so) and now I am trying to figure out the TGs. Due to my location and work schedule, I leave my BCD436 running all day recording traffic in my vehicle. The main users appear to be parking services and the student shuttle. However, when I hit playback at the end of the day, one TG will appear and when the person responds to the original call another TG appears. In other instances, it appears the TGIDs are completely wrong altogether because the voice traffic doesn't add up to the TGs I've already identified. I'm familiar with the UIDs not matching the voice on the recording playback but not a separate TG. Any ideas on how to determine which TGs are real and the ones displayed are false using the 436? I don't have an SDR and don't have the technical know how to make it work so I'm sticking with just my 436.

Suggestions?
 

kh6sz

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Yes, my 436 is doing the same thing. For instance, I record 1 system, a small casino locally, and so far I've found over 200 talkgroups for that 1 casino. I know it's not using that many! And I have the same system programmed into my TRX-1 with a wildcard and have found about 15 talkgroups, which is about right for casinos in this area. The 436 has been doing this for a long time now, pretty much makes the 436 useless to find new talkgroups.
 

Jay911

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I'm a little concerned about this too. I let my 436 and 536 record all week long and then dump the recordings to my computer on the weekend for review. TGs that are out-of-place on a given system are littered throughout my recordings. For example: a system which has TGs 1, 2, 3, 4, 5, and 6 suddenly sprouts TG 1301 (which is in use in a nearby system).

In my experience it is not a case of the two systems having the same frequency and color code and my radio(s) receiving "the wrong system" for the favorite list entry, before anyone raises that. I haven't noticed if it is only on Cap+ per the thread title, or if it happens on Con+ too.

UPMan, if you get wind of this thread - would you like debug logs?
 

crash1

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Yeah I've been having a problem with my 436 for a long time it misses talk groups and sometimes it doesn't show the talk group sometimes it shows 0 and not the talk group DMR trunking isn't even close to being ready
 

exkalibur

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It's because Uniden doesn't either know how, or won't, make firmware that works properly. My 536 false decodes all the time to the point where it's nearly useless.

Others have speculated that there's little to no error correction taking place - this would sure explain why you're seeing all kinds of bogus information.

Sent from my iPhone 8 using Tapatalk.
 

sibbley

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I'm a little concerned about this too. I let my 436 and 536 record all week long and then dump the recordings to my computer on the weekend for review. TGs that are out-of-place on a given system are littered throughout my recordings. For example: a system which has TGs 1, 2, 3, 4, 5, and 6 suddenly sprouts TG 1301 (which is in use in a nearby system).

In my experience it is not a case of the two systems having the same frequency and color code and my radio(s) receiving "the wrong system" for the favorite list entry, before anyone raises that. I haven't noticed if it is only on Cap+ per the thread title, or if it happens on Con+ too.

UPMan, if you get wind of this thread - would you like debug logs?
False TGID's have been happening from the beginning. It's all flavors of DMR on my end. I'm always finding one systems TGID's in another system's logs using proscan.
 

jhampton2000

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False TGID's have been happening from the beginning. It's all flavors of DMR on my end. I'm always finding one systems TGID's in another system's logs using proscan.
I think signal quality plays a big factor in this.....I have the same issue at times, but then I see the same occasional false-positive behavior with DSD+
 

mikewazowski

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This happens all the time which makes searching for new groups impossible.

The traffic on the group is correct for the system but the group displayed is from another system stored in the scanner.
 

NCFireman11

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I think signal quality plays a big factor in this.....I have the same issue at times, but then I see the same occasional false-positive behavior with DSD+
You may be right but in my case I'm 1.5 miles away from the site with full signal. How do you get much better quality than that short of sitting under the transmitter site?

Glad to hear I'm not the only one with issues getting false TGs. I'm pulling my hair out trying to figure MotoTRBO with my 436 and I've been fooling around with it since last year with the weekly firmware testing UPman was sending out.
 

Jay911

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I'm thinking it's possible it's not signal strength related. Or I could be about to describe to you all a completely unrelated issue.

Take a look at this screenshot from the media program I use to review my recordings after moving them from the scanner to the computer:



Apologies for the width.

Note that the two recordings are from different channels, recorded immediately one after the other, and both show "TGID:405" at the right side of the image (under the "comment" header). I can absolutely guarantee that the second recording, an analog transmission on a Search and Rescue frequency, does not have a talkgroup.

If you look at the header of these recordings in a text editor such as Notepad++, or maybe a hex editor or something else that lets you see the data byte by byte in "ASCII format", you will see how they store all this data in ID3-style tags (normally used in MP3s). For example, the "Marriott 461.7125" data shown under the "Artist" column is stored in the file after the "IART@" tag, with three NUL characters between the @ and the M in Marriott. Apparently, they don't flush the data in these fields in between recordings. I don't want to post the entire header because it's too large, but for example, the "Genre" column for the Marriott recording shows like this in Notepad++:

IGNR@<NUL><NUL><NUL>Unknown<NUL>Airways<NUL>tch<NUL>h<NUL>HF/VHF/UHF Simplex<NUL>

Everything after "Unknown" is from previous recordings, with titles like "Prairie Airways" and "Simplex Frequencies - HF/VHF/UHF Simplex". It appears they just write a <NUL> after the last character in the current datum, and leave the rest to be ignored.

The TGID in the image above, shown under the Comment heading, is stored in the ICMT@ field. In both my recordings it appears to be:

ICMT@<NUL><NUL><NUL>TGID:405<NUL>

whereas in some other recordings the field has been "blanked" with a <NUL> in the first position, as in:

ICMT@<NUL><NUL><NUL><NUL>GID:4000<NUL>

I have no idea if they actually take the TGID for the display of the radio/storing of the TG from this data, or if this data is populated from where they store the TG, if you know what I mean. Probably the latter.

(For what it's worth, the field that shows up as "31 15-35-14" in the image has just <NUL> in the field in the WAV header. It appears that it's inferring part of the filename as the title. Could be my media program.)

RR user theaton may have more to contribute regarding the header data - he's the one who wrote WAV Header Reader.
 

OceanNora

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I've been having a similar issue as well, but it seems to happen more with Connect Plus and One-Frequency rather than Capacity Plus systems for me. I've also noticed that it seems to occur more frequently with one Connect Plus system (Comtronics-MA) rather than another (Industrial Communications and Electronics). I'm not sure if it makes a difference, but I'm only able to pick up one Comtronics (problematic system) site from my position, rather than 3 from the other Connect Plus system.
 

jhampton2000

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Jay911....can you tell me what that program is that you use in that screenshot please?

I realize I didn't make my theory very clear earlier......because I see similar issues in DSD+ decodes with false positives, I don't think it's a problem limited to the BCDx36HP. I get false positives on my TRX1 too, I think this might be more of a decode quality issue (I said signal quality earlier which was ambiguous). Is it a FEC issue, or more to the point, a lack of FEC? Dont seem to see the issue on my DMR transceivers.

Of course, all 3 platforms might have completely different problems that manifest themselves as false positive TGIDs. I do know it gets worse with poor signal strength. BUT it isn't just a signal strength issue afaik...that I do agree with.
 
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wx5uif

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I've had false TGs too. Usually I'll play back a recording that I am trying to identify, right now hospital frequencies, and hear a local ham conversation on the talk group.


Sent from my iPad using Tapatalk
 

Jay911

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That's MediaMonkey. It's a shareware media player/library manager similar to iTunes but for all sorts of audio and video files. You can point it at a folder on your computer and have it display all the media files in that and subsequent/child folders. So I dump all my recordings from my scanners into various folders under C:\radio\recordings\ and just tell the program to show me everything in (and below) \recordings\. Very nice - you can edit tags on one or many files, and when you're cataloguing an actual library of music, you can convert them all to one format and bitrate, level the volume so they're all reasonably the same loudness, etc.
 
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