TRX-2: Issues With DMR Trunked System

[Ubbe]

1098 have probably other values for the squelch than TRX-2. The 8 on TRX-2 are normally the lowest setting that closes squelch after it has opened.

/Ubbe

 

[mfn002]

The 8 squelch will probably receive signals too noisy to be decoded and will hesitate on that CC too long until it will continue to scan.

First check that you can successfully decode the signal while entering the voice channel manually to monitor it stationary. If that works you can then adjust parameters for scanning.

The dwell time depend on how many control channels you have in the system. I would recommend 0.3 sec per CC that you can hear at one time. If you hear 3 CC then use 1 sec, if you hear 6 CC then use 2 sec.

If the system doesn't use, or rarely use, the slot 2 on the CC I recommend that you remove the CC frequencies. TRX uses dwell time per system, not per site as 536, so it depends on how many simultaneous carriers with DMR signalling you scan and how many TGs you lock out. If you monitor all TGs then the default 1 sec will be more than sufficient. If you lock out a lot of TGs and only monitor a couple, then you need to calculate how many simultaneous active voice channels you can receive and multiply with 0.3 sec and if the system often gets fully loaded with voice traffic then you also need to have the CC channels in scan and must also consider 0.3 sec per CC.

For testing purposes you can easily try a 5 sec dwell time just to be sure that you do not have a dwell problem. But as I have mentioned, check that you can monitor the voice channel manually that the 536 uses when you do not get anything when the TRX are scanning.

/Ubbe

I put the 5 second dwell time in, but I'll have to wait until tomorrow when the system is more active to see if it works and try that experiment with the voice channels. When I first started gathering info on the system, I was only able to locate one active CC, which was on 854.38750. I do notice that when the scanner skips over an active TG on the system, it'll briefly show the "T" icon at the top of the screen but not stop on the system.

Another thing that I don't think I mentioned was that this is a Tier III CapMax system, if that makes any difference.

 

[Ubbe]

It shows that T during the delay period for the systems TG, not your scanners. It indicates that the TRX hit that frequency between PTTs and will probably be solved by using a longer dwell time.

If it skipped the frequency while someone where talking then you could try and enter the voice channels 3 times after each other in that site. It will give the TRX 3 times longer time to try and decode the signal.

Do both things and if it works then do only one thing to see what was most effective and then try and reduce dwell time and number of duplicate frequencies to find the most effective way to scan the system.

TRX doesn't care what type of DMR system it is, it just scans all voice channels you have programmed for active calls and when one users let go of his PTT the TRX scans all channels you have programmed in the system for that TG to appear again during the scanners delay time and when the timer runs out it continues to scan other systems.

/Ubbe

 

[mfn002]

It shows that T during the delay period for the systems TG, not your scanners. It indicates that the TRX hit that frequency between PTTs and will probably be solved by using a longer dwell time.

If it skipped the frequency while someone where talking then you could try and enter the voice channels 3 times after each other in that site. It will give the TRX 3 times longer time to try and decode the signal.

Do both things and if it works then do only one thing to see what was most effective and then try and reduce dwell time and number of duplicate frequencies to find the most effective way to scan the system.

TRX doesn't care what type of DMR system it is, it just scans all voice channels you have programmed for active calls and when one users let go of his PTT the TRX scans all channels you have programmed in the system for that TG to appear again during the scanners delay time and when the timer runs out it continues to scan other systems.

/Ubbe

I tried everything you suggested and all indications are that it should be working, but it isn't. I entered each of the frequencies three times and increased the delay to 10 seconds. I am still missing traffic.

 

[seth21w]

Try adc at 0 or +2

 

[mfn002]

Try adc at 0 or +2

ADC?

 

[seth21w]

ADC?

Yes it's in global settings menu along with dsp level adapt and dac. Look in the menu.

 

[seth21w]

How many signal bars do you have when you recieve things?

 

[Ubbe]

DSP and ADC settings do nothing for DMR systems.
If it's ok with you, can you attach a saved cdat backup file to a message and we can check if there are any settings that could relate to your problem?

It could be some local RF problem. Do you have all scanners connected to the same antenna or do each scanner only use the included clip on antenna?

It could be some file transfer problem as the TRX and EZscan doesn't indicate when a trashed file have been transfered, there's no checksum control. I have had problems that where solved by entering the same values again but manually on the scanner. Everything looked okay when checking the data on the scanner but entering them again cleared the problem.

Try and make a new system manually on the scanner and enter the frequencies directly on the scanner, don't bother getting the names correctly as its only for testing and enter only a wildcard for TG and radio id.

Laptops usually have a SD card reader/writer. You can move the SD card to you laptop for programming to get a more secure, and faster, connection.

/Ubbe

 

[TampaTyron]

Do CapMax systems have the ability to encrypt/obfuscate the control channel in a way to prevent non authorized radios from following? TT

 

[seth21w]

DSP and ADC settings do nothing for DMR systems.
If it's ok with you, can you attach a saved cdat backup file to a message and we can check if there are any settings that could relate to your problem?

It could be some local RF problem. Do you have all scanners connected to the same antenna or do each scanner only use the included clip on antenna?

It could be some file transfer problem as the TRX and EZscan doesn't indicate when a trashed file have been transfered, there's no checksum control. I have had problems that where solved by entering the same values again but manually on the scanner. Everything looked okay when checking the data on the scanner but entering them again cleared the problem.

Try and make a new system manually on the scanner and enter the frequencies directly on the scanner, don't bother getting the names correctly as its only for testing and enter only a wildcard for TG and radio id.

Laptops usually have a SD card reader/writer. You can move the SD card to you laptop for programming to get a more secure, and faster, connection.

/Ubbe

Dmr is tdma digital format just the same as p25 and i havent seen or heard any official statement as to whistler saying those settings only effect p25, so please if you can back up your information a little more please let me know.

 

[Melv7956]

Does the system you are trying to monitor have ras enabled? My trx-1 and trx-2 used to work fine on all systems and then whistler released an update that gives "improvement on ras enabled systems" and from that moment both systems near me with ras enabled now misses great chunks of voice traffic.


Sent from my iPhone using Tapatalk

 

[mfn002]

DSP and ADC settings do nothing for DMR systems.
If it's ok with you, can you attach a saved cdat backup file to a message and we can check if there are any settings that could relate to your problem?

It could be some local RF problem. Do you have all scanners connected to the same antenna or do each scanner only use the included clip on antenna?

It could be some file transfer problem as the TRX and EZscan doesn't indicate when a trashed file have been transfered, there's no checksum control. I have had problems that where solved by entering the same values again but manually on the scanner. Everything looked okay when checking the data on the scanner but entering them again cleared the problem.

Try and make a new system manually on the scanner and enter the frequencies directly on the scanner, don't bother getting the names correctly as its only for testing and enter only a wildcard for TG and radio id.

Laptops usually have a SD card reader/writer. You can move the SD card to you laptop for programming to get a more secure, and faster, connection.

/Ubbe

I originally had the TRX-2 connected to the stock antenna, but I've since switched it over to the same antenna that one of my 536s is on. It doesn't seem to make any difference.

I tried to post of copy of the CDAT file, but it says that the file is too large.

 

[Ubbe]

I've tried all different settings on both full signal DMR systems and weak ones using old and new firmwares and there have been absolutly no difference in decoding the systems.

Manual only says that the DSP level are for how fast the DSP adjusts to different P25 levels, whatever that means. Is it like the time constant for the audio AGC?

The level into the DSP for signalling decoding can only be adjusted 4dB, way too little to make any difference. I begin to think that Whistler have it the wrong way around. Output level from DSP can be adjusted 12dB, way too much when matching digital decoded audio level with the analog level. If DAC and ADC settings where switched around it would make much more sense.

The old firmwares where terrible at decoding DMR and where much worse than Uniden. Then came Whistler with a new firmware and suddenly it decodes better than Uniden. Still some bugs in newest FW with Tier III system when a user release PTT the audio sometimes are opened up for a second so that DMR signalling are heard before it mutes again. The DSP settings remained the same and still had no effect on the DMR decoding success rate.

/Ubbe

Dmr is tdma digital format just the same as p25 and i havent seen or heard any official statement as to whistler saying those settings only effect p25, so please if you can back up your information a little more please let me know.

 

[mfn002]

I increased the system dwell time to 10 seconds, and I seem to be picking up more traffic, but still not everything.

 

[Ubbe]

When you increase dwell time it scans the frequencies a lot more and increase the chance to hit the frequency at the sweet spot in the data stream. Seems to be extreamly difficult to decode that system with the TRX-2.

When you do hear a conversation, does it continue to monitor it until the user releases his PTT? Then the best solution would be to multiply the voice frequencies instead of a long dwell time. That way it will stay on the same frequency much longer and have time to decode properly.

/Ubbe

 

[mfn002]

When you increase dwell time it scans the frequencies a lot more and increase the chance to hit the frequency at the sweet spot in the data stream. Seems to be extreamly difficult to decode that system with the TRX-2.

When you do hear a conversation, does it continue to monitor it until the user releases his PTT? Then the best solution would be to multiply the voice frequencies instead of a long dwell time. That way it will stay on the same frequency much longer and have time to decode properly.

/Ubbe

It continues to monitor as long as the PTT is pressed. I entered each of the voice frequencies three times, which seems to make things a little better.

 

[troymail]

Curious -- I looked up the license and it says there are two sites - one with 11 frequencies and the other with 4 frequencies. The listing on RRDB says there are 6 frequencies....

What do you actually have programmed?

 

[Ubbe]

Michael, enter these frequencies and see what happens.
It most probably are a missing frequency problem but don't know why the 536s scans ok.
Maybe the Uniden and Whistler databases are different.

/Ubbe

854.0125
854.3875
856.2625
856.9375
857.2625
857.7375
857.9625
858.2625
858.9625
859.4375
859.9375

 

[troymail]

Michael, enter these frequencies and see what happens.
It most probably are a missing frequency problem but don't know why the 536s scans ok.
Maybe the Uniden and Whistler databases are different.

/Ubbe

854.0125
854.3875
856.2625
856.9375
857.2625
857.7375
857.9625
858.2625
858.9625
859.4375
859.9375

I can't even import this system with Uniden Sentinel.... imports fine in EZ Scan but I am wondering if the 6 frequencies listed are incomplete.