BCD436HP: Problems with N9600 conventional? NXDN

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frazpo

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Ok, re-reading through the entire thread again, I suspect there are two things going on here:

The System:
1. The OP is listening to a system simply with an odd configuration. From what's been posted, it isn't trunked (DSD+ shows as CB96), it isn't simulcast (there appear to be multiple frequencies in use but I've seen no mention of multiple transmissions on the same frequency) and the odd data bursts might be due to something not yet understood (eg AVL etc). I think DSD+ would be the best tool to further investigate. So I don't believe the oddities of this NX96 system are the root cause of why the 436 isn't functioning as expected.

NX96 on a 436:
2. Several people are posting issues with missed NX96 transmissions. I have access to multiple 436's, a TRX1 and several NX48/NX96/DMR handhelds, so I've now spent a few hours running a number of side-by-side tests. All tests are on simplex Conventional channels, results are consistent across VHF and UHF, and between 436's. The 436's are both early models, both have self-mod C1 caps fitted, neither have had clock issues [yet !]. I've found:

a. Across all tests, FM works better than NFM (most noticeable on NX96, some improvement on DMR, little difference between NFM and FM on NX48)

b. I too can confirm AUTO Digital Threshold mode decode of NX96 is inconsistent.I too get the 'missed calls' behavior (it's like the NX96 signal doesn't exist, or the 436 is asleep). Frustratingly I can't pin point a set of circumstances where I can consistently replicate the problem. I have even seen several tests where two identically configured 436's behave differently on the same signal - one decodes, the other is asleep.

c. For me, Digital Threshold Mode Manual 10 gives best results for NX96. Others might (and have) find a different threshold works best. It rarely ever misses a call but will display higher ERR rates vs an AUTO setting (assuming the AUTO setting detects/decodes the signal in the first place). NFM seems to react slower than FM in this setting.

d. An incorrect Manual setting will render the 436 completely deaf to NX96, NX48 or DMR (eg setting Manual 12 vs 10 for NX96 consistently makes it deaf). Same issue for NX48 if the Manual setting is too far from the correct threshold.

e. For me, Auto Digital Threshold mode (noted working at 10) gives best results for NX48 and DMR. In contrast to the previous Firmware release, I used to have to run Manual 5 to have any chance of some simplex DMR decoding - even then it was hit and miss. Now I completely rely on an Auto Threshold setting, and DMR simplex is vastly improved as a result. I can even run repeatable tests where Manually setting one 436 to 10 won't work while the other 436 sat next to it is happily the decoding the same signal on Auto (showing 10).

3. So in conclusion:
a. I do believe there is a digital threshold related issue with NX96 decoding. It has similar traits to the DMR simplex problems when the DMR upgrade was first released. But fixing it might impact performance on DMR/NX48 (and possibly other formats).

b. FM is better than NFM all round. In theory that shouldn't be the case, but that's what I've found.

c. For NX48 and DMR Simplex I would recommend Auto Digital Threshold.

d. For NX96 I would INITIALLY recommend Auto Digital Threshold, then use FUNC+Volume to note the best threshold value, and then add this Manually to the System.

e. For Searching for mixed modes I would recommend Auto Digital Threshold, but be aware you might miss some NX96.

HTH

Jim


This explains a lot and the changes that you and others brought up have definitely improved the receive rate. I will continue to experiment with the settings mentioned. Thanks for the explanation.


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frazpo

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I am monitoring a 9600 system as NXDN Trunked. For reference this would be the system https://www.radioreference.com/apps/db/?sid=9209



I'm using Auto Threshold (Threshold Level 8), and Auto Modulation and it's working very well. I'm scanning two sites. Early on I had Modulation set as NFM, and things didn't seem to work as well. The 436 seemed to be missing things compared to the TRX-1. Once I switched to Auto they seemed to be fairly equal. I tried some different Manual Threshold settings and that also seemed to make things worse. Auto seems to work best for me.



I'm also scanning a conventional NXDN 4800 1 frequency as conventional since there is only 1 TGID. Auto Threshold (Threshold Level 8). Not much traffic, but decodes well. Once this 4800 frequency picks up in comms, I'll try it as OFT.



I have to say the TRX-1, even though it doesn't trunk, can keep up with the 436 on the trunked system. Only real difference is the 436 does not drop in the middle of a conversation where the TRX-1 still drops at times.



In my case, I think Uniden did a great job with this upgrade.


Yes. The 4800 trunk I monitor does extremely well. And your right the trx does well but the 436 is more reactive on catching the beginning of the transmissions.

So your 9600 trunk that you monitor has a dedicated CC. ??


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frazpo

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This is something that really needs addressed. I can see this causing frustration for people not knowing what to adjust. Mine was so bad prior to adjusting settings that I thought the upgrade had severe issues with N96.
Hoping this will be considered in future updates. Something is definitely not right somewhere with N96 conventional.
 

VA3DBJ

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This is something that really needs addressed. I can see this causing frustration for people not knowing what to adjust. Mine was so bad prior to adjusting settings that I thought the upgrade had severe issues with N96.

Hoping this will be considered in future updates. Something is definitely not right somewhere with N96 conventional.

As soon I made the FM change, I have been experiencing better results. Still misses a few, compared with DSD+, but way better then using auto.


VA3DBJ

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sibbley

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Yes. The 4800 trunk I monitor does extremely well. And your right the trx does well but the 436 is more reactive on catching the beginning of the transmissions.

So your 9600 trunk that you monitor has a dedicated CC. ??


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Correct, dedicated control channel, no voice.
 

vocoder

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Frazpo,

What type of antenna are you using?

I was using an outdoor antenna, but now i am using the stock antenna, same results
 

frazpo

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Frazpo,



What type of antenna are you using?



I was using an outdoor antenna, but now i am using the stock antenna, same results


Ive experimented. The stock antenna, and diamond multi band. It seems be doing ok now. Changing it to FM seemed to have helped quite a bit. Still may miss but way better.


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UPMan

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If someone experiencing this could log while conventionally scanning for a couple of minutes. Then, zip it up and attach to this thread, our engineer will take a look at it. Use AUTO for modulation (not set to NFM or FM).



To make a debug log, power on while pressing AVOID. Then set SETTINGS --> Set Debug Mode to File (SD Card). After scanning for a couple of minutes, SETTINGS --> Set Debug Mode to Off. Then, the file will be in the scanner's debug folder.


Also, if you could confirm that there is no adjascent or co-channel interference.
 

VA3DBJ

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If someone experiencing this could log while conventionally scanning for a couple of minutes. Then, zip it up and attach to this thread, our engineer will take a look at it. Use AUTO for modulation (not set to NFM or FM).

To make a debug log, power on while pressing AVOID. Then set SETTINGS --> Set Debug Mode to File (SD Card). After scanning for a couple of minutes, SETTINGS --> Set Debug Mode to Off. Then, the file will be in the scanner's debug folder.

Also, if you could confirm that there is no adjascent or co-channel interference.
Attached is my debug file. No interference from other channels.

for this system: https://www.radioreference.com/apps/db/?sid=8053
 

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frazpo

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I will send logs by the weekend. I am currently out of town. Thanks for looking into this.


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UPMan

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1. The scanner seems to have a hard time synchronizing as NXDN 9600, because there are times when it is misdetected as NXDN 4800.

Is the receiving signal level strong enough?

Or are you completely certain that there is really no co-channel interference?

2. There is radio traffic on TGID 0 (all group call).
TGID 0 can be received in conventional mode only at this time.
 

frazpo

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log file

Log file attached. Yes, I am monitoring a very good signal with no interference.
In auto mode the modulation is going to FM. Is this normal for a N9600 frequency?
 

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f4jmk

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1. The scanner seems to have a hard time synchronizing as NXDN 9600, because there are times when it is misdetected as NXDN 4800.

Is the receiving signal level strong enough?

Or are you completely certain that there is really no co-channel interference?

2. There is radio traffic on TGID 0 (all group call).
TGID 0 can be received in conventional mode only at this time.
Signal is strong

Attached another log, different frequency to help rule out any co-channel interference.
 

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UPMan

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Log file attached. Yes, I am monitoring a very good signal with no interference.
In auto mode the modulation is going to FM. Is this normal for a N9600 frequency?
1. This is a conventional NXDN and all TGIDs are 0, which is not yet supported. For now, program as conventional. We will be issuing an update to support TGID 0 in trunk mode so that you can use it with all the trunking features (UID).

2. Two RANs were included in the log. One is 10 and the other is 20. If these were both from the same frequency, you might be getting co-channel interference from two different systems.
 

UPMan

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Signal is strong

Attached another log, different frequency to help rule out any co-channel interference.
1. Is your model 436 or 536 or both?
2. What is the squelch setting?
3. What is the frequency?
4. When the frequency is held in conventional mode, is reception improved?
5. Is there any other NXDN system that you have been receiving?
 

f4jmk

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1. Is your model 436 or 536 or both?
2. What is the squelch setting?
3. What is the frequency?
4. When the frequency is held in conventional mode, is reception improved?
5. Is there any other NXDN system that you have been receiving?
1.Both, used the 436 for the logs ( with standard duck, the second log was on an outdoor antenna )

2. 2

3. 158.775

4. Scanning 4 frequencies during both logs, I will try holding.

5. All conventional NXDN 9600 close by, there are some 4800 conventional a few counties away, one is encrypted though.
 
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