TRX-1 Missing DMR Transmissions

Thanks to Jeff at Hamstation I have a BCD436HP available to me now to do a side by side comparison with my new TRX-1.

Currently both the TRX-1 and BCD436HP are connected to the same antenna via a multicoupler. Both have the latest firmware updates. Both are programmed to scan two Con+ DMR trunked systems. Each of these have two sites. Both of these systems are programmed with a wildcard for the TRX-1 and ID SEARCH on the 436 to supposedly hear all traffic. Each Con+ system has a site local to me with a pretty strong signal. The TRX-1 has a third scanlist which contains conventional DMR. All entries are programmed using wildcards, i.e. cc:*,tg:*,sl:*. The 436HP has its conventional DMR programmed as single channel trunked systems and loaded via ARC536 Pro software. Again, both scanners are only programmed to receive the same exact systems, nothing "extra" in either.

The TRX-1 and 436HP seem relatively close on the Con+ systems although I have watched the TRX-1 scan right by a talkgroup that the 436HP is currently receiving on a few occasions. The largest issue I see is with conventional traffic. The TRX-1 is flat-out missing a volume of traffic from my local Eversource electrical utility company on a frequency of 451.125. The signal is very strong and that can't be used as a reason for non-reception. There are similar issues with other conventional frequencies albeit with weaker signal levels.Yet, the TRX-1 has no issue receiving other conventional traffic in the UHF range and keeps up fine with the 436. The programming for the ones that work and the ones that don't is exactly the same as shown in the example in the first paragraph.

I'm stumped as to why this is occurring other than it's early in the game for both and there will surely be improvements in firmware. But why exact same methods of programming for conventional DMR in the TRX-1 provides drastically different results is mystifying. Any suggestions, and/or if anyone else has both to compare, have you noticed anything similar?

Squelch levels are the same?

Well the squelch was at about noon on the TRX-1. For the sake of testing I rotated it fully counter-clockwise as I'm exclusively scanning DMR stuff. No difference though. Working on a few other things but it appears to me that the described behavior is continuing.

Even with the squelch at 12 o'clock, the signal from the frequency not being received is strong enough so as not to be an issue, or I would surely think.

turn On the attenuation only on the freqs its having trouble with and see if that helps

I am not experiencing this kind of issue,maybe your TRX-1 is attached to an antenna thats giving it intermod,the scanner is extremely sensitive.They sell aftermarket attenuators.I am using its antenna and have no issue with rreception.The hams cant hide on DMR anymore! On the flip side of that I had a BCD-436HP and it missed P25 traffic that the Whistler did not.

This is occurring regardless of what antenna it's connected to. Right now I have the Uniden and Whistler side by side, both using a Radio Shack 800 MHz rubber duck antenna. Symptoms are the same.

I'm going to try some different programming. As it is now I have the Con+ trunked systems programmed with multiple sites. I will reprogram them to use only the site most local to me. As far as the conventional systems I remain mystified.

Whistler has my current programming file at this point, and I actually had a lengthy conversation with one of their techs on Friday afternoon. They're looking into it as well.

K2OOL, are you actually doing a side by side comparison using a BCD436HP and basing your statement on that?

I have said this in another spot but is the problem that the scanner has to be on the system when the data stream is transmitted to ID user TG ect and the scanner keeps missing the key information because it is not on the frequency when the data is sent or repeated? Running down the road with my TRX-2 and BCD536HP at times they both lock at the same time then at times one locks on a signal and a few seconds later the other locks on the signal. If both scanners are locked on 1 system (not scanning) looking for TG's they both always hear at the same time.

Somewhat related, I've noticed my TRX-2 misses some DMR transmissions that DSDplus + Airspy has no problems with... that being said, I've only had my TRX-2 for a few days so I can't really blame it all on the radio itself yet.

Reducing the amount of sites being scanned per system has resulted in some improvement. Maybe scan speed is a factor as well. That said I've watched the 436HP active on a TG for long transmissions and the TRX1 never stopping on the same transmission.

The default dwell time on trunked systems defaults to 1 second. I may cut that value in half and see if there are further improvements. Without looking at the numbers I'm relatively sure that the Uniden scans faster than the Whistler, which I believe is 70 CPS. I'd have to look up the Uniden value.

As far as the data stream comment goes, I don't think that's a factor as both scanners do stop on traffic that is clearly already in mid-transmission, as in the sentence being spoken is already in progress.

I shortened up the dwell time on the DMR systems I'm scanning and it seems to have helped a bit also. The true test will be when normal business activity returns Tuesday.

Right now though I would have to say that the BCD436HP is outperforming the TRX-1 when scanning the same mix of trunked and conventional DMR.

After watching these two scanners side by side during "regular business hours" I have to conclude at this time that currently the BCD436HP is indeed outperforming the TRX-1 with regards to DMR. No need to rehash my conclusions, they're all stated in the above messages.

DMR Scanning

Thanks for reporting back on your TRX-1... I've been doing more testing with Airspy+DSD and my TRX-2. It seems that when the TRX-2 is parked on a single DMR frequency it does MUCH better than Airspy/DSD...picks up more calls and the audio sounds way better. However when the TRX-2 is scanning DMR channels it's another story.

I have a DMR bank with only 7 frequencies, all channels have 0 delay and yet DSDplus will be 2 seconds into a transmission before the TRX-2 finally picks it up. Seems like an awful long time to sift through 7 channels? I would say something is very broke with the scanning portion of the DRM capability. Whislter folks definitely need to look into this.

This is all new technology and hopefully firmware updates will improve things. I want it to be clear that my comments are strictly observations and not a knock on the product. From an audio standpoint I find the Whistler superior to the Uniden, but I surely currently hear a lot more audio from the Uniden.

Not trying to knock the product either.... The last scanner I bought was a Uniden BC785D...so just trying to figure out if the issue is me or the radio,

If I can catch it on video, I will post it on youtube, maybe it will help the developers figure out what's going on, or if it's simply a settings issue.

Videos of TRX-2 Missing DMR audio

Note sure if this should be in a separate thread, or combined into one with the TRX-1 missing DMR thread?...

I've posted some videos on YouTube showing some issues the TRX-2 is having with scanning DMR frequencies. It seems to work wonderfully monitoring a single channel, but has issues when scanning. I'd like to hear any recommendations people have as far as settings go.

The TRX-2 was scanning a DMR only scanlist consisting of 7 frequencies, and the Airspy/SDR#/DSDplus was tuned to 153.2000 MHz @ 8000 Hz BW. Both radios were sharing the same antenna via a 4-port Stridsberg multicoupler.

In the videos you will see DSDPlus detect and start playing audio while the TRX-2 continues to scan, and on occasion you will see the TRX-2 drop audio and start a scan during the middle of a transmission.

DMR 1 https://www.youtube.com/watch?v=aH-CnPbrQtg

DMR 2 https://www.youtube.com/watch?v=riF5g5VxPCo

DMR 3 https://www.youtube.com/watch?v=WAK_-YlrvHY

If you all want to see something different or have other questions about my setup, please let me know.

Regards,
-Tim

Scott thanks for the updates keep us posted. I have also noticed better performance and less missed calls by locking a scanner on one system. This does not matter 436, 536, 996p2, 785D, 668, pro18 197, 106, and TRX-2 they all work better locked on one system no missed calls.

mitreffahcs said:

Thanks for reporting back on your TRX-1... I've been doing more testing with Airspy+DSD and my TRX-2. It seems that when the TRX-2 is parked on a single DMR frequency it does MUCH better than Airspy/DSD...picks up more calls and the audio sounds way better. However when the TRX-2 is scanning DMR channels it's another story.

I have a DMR bank with only 7 frequencies, all channels have 0 delay and yet DSDplus will be 2 seconds into a transmission before the TRX-2 finally picks it up. Seems like an awful long time to sift through 7 channels? I would say something is very broke with the scanning portion of the DRM capability. Whislter folks definitely need to look into this.

Click to expand...

Thank you for everyone's feedback. I have an engineer looking into these issues. When I have any feedback I will let everyone know!

one thing i noticed but i maybe wrong reading dsd.

isnt the whistler missing timeslot 2 traffic? But much better on SLOT 1?
or do i have that all wrong??
dmr 3 vid what is dsd ch=2 dsd hears fine but nothing on whistler untill ch=1 then whistler fine?

jeff

mitreffahcs said:

Note sure if this should be in a separate thread, or combined into one with the TRX-1 missing DMR thread?...

I've posted some videos on YouTube showing some issues the TRX-2 is having with scanning DMR frequencies. It seems to work wonderfully monitoring a single channel, but has issues when scanning. I'd like to hear any recommendations people have as far as settings go.

The TRX-2 was scanning a DMR only scanlist consisting of 7 frequencies, and the Airspy/SDR#/DSDplus was tuned to 153.2000 MHz @ 8000 Hz BW. Both radios were sharing the same antenna via a 4-port Stridsberg multicoupler.

In the videos you will see DSDPlus detect and start playing audio while the TRX-2 continues to scan, and on occasion you will see the TRX-2 drop audio and start a scan during the middle of a transmission.

DMR 1 https://www.youtube.com/watch?v=aH-CnPbrQtg

DMR 2 https://www.youtube.com/watch?v=riF5g5VxPCo

DMR 3 https://www.youtube.com/watch?v=WAK_-YlrvHY

If you all want to see something different or have other questions about my setup, please let me know.

Regards,
-Tim

Click to expand...

I hadn't even looked at that, I'll do some more digging and see if I can come up with something conclusive. It did seem pretty random, real hit or miss, so could be.

look at your third vid on the ch=2
then when we see ch=1 whistler hears that.
thanks for videos.
one more thing someone answer on this video thats dmr 3 i see talkgroup 101 per dsd showing up on slot 1 and 2?
can a single talkgroup on a single dmr freq be on BOTH slots???


jeff[
QUOTE=mitreffahcs;2604115]I hadn't even looked at that, I'll do some more digging and see if I can come up with something conclusive. It did seem pretty random, real hit or miss, so could be.[/QUOTE]