TRX-2: Whistler TRX2 NXDN Problem

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anelson5004

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I am trying to monitor NXDN Frequency 155.535, which is Bluefield VA Police Department and it only transmits half and half, and only at night, and I have it programmed in conventional mode. When it transmits at night, I am only catching part of the conversation sometimes just the tail end for only like 2 minutes, and it flashes a "T" for talk group like it is supposed to.. There are times that I receive only an "S" with 3 signal bars and no audio behind it, as well. I am connected by an outdoor antenna, with it pointing directly at Bluefield VA.I am unable to access the talk group number in order to program Bluefield VA Police Department as a trunked radio system. It is listed on here as conventional with the mode being NXDN. I have RAN set to any and I have also tried setting it as 0 which is there Radio Access Number according to my scanner, what little time it does transmit and it shows NXDN48 what little time it does transmit. According to digital Frequency finder they are only running 45 watts power, not sure if that will help anyone. I am receiving Bluefield WV Police Department without any trouble at all, and they are on a P25 Phase 1 system which I am aware is a completely different system than NXDN. Any help that anyone can provide will be greatly appreciated.

Thank you
anelson5004
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SCPD

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It's not uncommon for police departments run half encrypted
and your scanner ignores it



I am trying to monitor NXDN Frequency 155.535, which is Bluefield VA Police Department and it only transmits half and half, and only at night, and I have it programmed in conventional mode. When it transmits at night, I am only catching part of the conversation sometimes just the tail end for only like 2 minutes, and it flashes a "T" for talk group like it is supposed to.. There are times that I receive only an "S" with 3 signal bars and no audio behind it, as well. I am connected by an outdoor antenna, with it pointing directly at Bluefield VA.I am unable to access the talk group number in order to program Bluefield VA Police Department as a trunked radio system. It is listed on here as conventional with the mode being NXDN. I have RAN set to any and I have also tried setting it as 0 which is there Radio Access Number according to my scanner, what little time it does transmit and it shows NXDN48 what little time it does transmit. According to digital Frequency finder they are only running 45 watts power, not sure if that will help anyone. I am receiving Bluefield WV Police Department without any trouble at all, and they are on a P25 Phase 1 system which I am aware is a completely different system than NXDN. Any help that anyone can provide will be greatly appreciated.

Thank you
anelson5004
anelson5004@gmail.com
 

Ubbe

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TRX scanners doesn't ignore encryptions.

Try entering the frequency as a NXDN trunked system, and also try both NFM and FM settings.

/Ubbe
 

troymail

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I'm not there and know nothing of the system or users which makes it hard to really provide anything definitive but here are some thoughts...

First, although the RRDB shows a single frequency, the license shows multiple conventional frequencies - some low band analog and others that are VHF with multiple emission types (not unusual). You may want to check some of these other frequencies to see if any are in use.

Keep in mind that the RRDB information is user submitted and may not be 100% accurate or complete (actually, you can't even trust he FCC ULS data 100% either).

Also, the fact that you are seeing the flashing "S" may mean the radio is detecting activity on the frequency that may not be voice. Unlike analog, digital transmissions could contain data transmissions of various types so it's possible that some information (think "conversations") is being passed as data which you can't hear/see.

There could be many other reasons you're seeing what you are seeing.

And finally, there could always be some type of bug that is a result of some type of "one-off" vendor specific feature. This can be expected in DMR and NXDN systems - in fact, it's one of the reasons for the big push in P25 - to provide consistent protocols and systems for public safety. DMR and NXDN don't have those types of restrictions.
 

anelson5004

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I tried both FM nd NFM settings, as well as the Auto settings in conventional mode and got the same results. Which type of trunking system would I use NXDN C or D and what talk group number would I use, given the fact I do not have the talk group number for the frequency?
 

theTastyCat

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OP, I've been having the exact same problems with my local NXDN system, which I've confirmed with DSD+ so I know exactly what it should sound like. Been working with Whistler tech support for months but haven't had the time to send in scanner and DSD files since the most recent update but hope too soon - it really stinks to miss about half of the traffic whether complete missing transmissions or signals dropping out.
 

Ubbe

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Troymail might have a point there. It could be several frequencies in the system and when the last mobile leave a site it stops transmitting and you'll have to follow the conversation from another site.

Try a search between 154 and 157 at night and check the result in the morning.

Program the trunked system as type D and make several sites, each with 155.535 but with different parameters FM, NFM and so on. Add talk groups and radio IDs with wildcards. You'll have to make a scanlist for this system.

/Ubbe
 

werinshades

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OP, I've been having the exact same problems with my local NXDN system, which I've confirmed with DSD+ so I know exactly what it should sound like. Been working with Whistler tech support for months but haven't had the time to send in scanner and DSD files since the most recent update but hope too soon - it really stinks to miss about half of the traffic whether complete missing transmissions or signals dropping out.
The TRX series are not decoding the Control Channel so this makes it difficult to follow conversations.
 

ben-scan

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Regardless of any 'issues' with the programming of the scanner or the used NXDN network I came to the sad conclusion that the Whistlers are not great at decoding NXDN. The audio quality is just rubbish most of the time. Especially compared to DMR. I know for a fact that the NXDN decoding is more complex and CPU / DSP intensive but I still hope whistler can improve their algorithms.
 

troymail

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I'm very confused by some of the responses to the original post/question in this thread.

Based on all available information, the user is asking about a conventional NXDN frequency. I really don't understand what all of the comments about trunked systems and DMR have to do with his question.
 

Ubbe

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I guess I'm lucky as most E transmission mute
You have the selection of mute, busy tone or to listen to the decoded audio when you encounter encrypted transmissions with a TRX scanner but it will not automaticly skip it as Uniden does. I prefere Whistlers solution as I would like to see the TGs and IDs but it would of course be better if they had a fourth selection with a skip option.

/Ubbe
 

Ubbe

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He has to try all options available and as TRX doesn't do trunk tracking it will work entering a conventional channel in a trunked system setup. Entering it in a trunked system are the only way to change parameters of a NXDN channel.

/Ubbe

I'm very confused by some of the responses to the original post/question in this thread.

Based on all available information, the user is asking about a conventional NXDN frequency. I really don't understand what all of the comments about trunked systems and DMR have to do with his question.
 

anelson5004

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I tried trunk tracking Bluefield PD as suggested using NXDN Type D, using both FM and NFM parameters and a wildcard talk group given I don't have the actual talk group number that I need, and It hasn't transmitted at all so far. I noticed it tried to transmit for 2 seconds in conventional mode according to my playback at 07:46 a.m. this morning. Any help you all can provide, will be greatly appreciated.

thanks
anelson5004
 

jhampton2000

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anelson5004,

So maybe we need to go back to some basics to get to the bottom of this:

>transmits half and half
When you say this, what exactly do you mean by this?

>it flashes a "T" for talk group like it is supposed to..
Note the TRX manual says it displays the T icon when "receiving trunking control channel data" But that isn't correct: it will flash on and off when receiving any NXDN4800 signal, conventional or trunked (a point raised several times with Whistler support, but they argue it is expected behavior !! I kid you not)

Some things to test:
- I'd recommend programming just as conventional using FM and with RAN/TG wildcards set and encryption audio set to Audio Tone or Digital Noise.

- Try programming the channel into memory as well as monitoring it via Tune Mode: for some functions, the TRX behaves/display different things depending on where it's tuned or in memory.

- If 155.535 is the repeater (?) downlink frequency, what can you hear on the uplink frequency?

- What happens if you tune +5khz and -5khz away form the center 155.535 frequency?

- Do you have a second scanner to listen to the raw NXDN4800 'noise' on the channel alongside the TRX, to check when the channel is active? Does the TRX always decode when the raw signal is heard on the other scanner?
 

Ubbe

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Perhaps it's difficult to monitor live if it only gets active at night.

Could you program the frequency as a conventional analog NFM channel and set it to record and choose it by using Browse Objects. Then listen to the recordings the next day if it sounds ok. A steady data stream while in idle and a varying data stream when there is voice communications. If you are unsure you could probably attach a sample to a message here.

/Ubbe
 

anelson5004

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JHampton 2000: I tried everything as you suggested, and my radio shack pro 197 made the raw encryption noise as it was supposed to, and My TRX did nothing not even in tune mode. I tried the uplink frequency and didn't hear anything on either scanner. I am going to attach what I am receiving. This was at 07:46 a.m. this morning. I am also attaching one that is from 6/21/2017 at 11:55 P.M. for comparison. Any help you can provide will be greatly appreciated.
 

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jhampton2000

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JHampton 2000: I tried everything as you suggested, and my radio shack pro 197 made the raw encryption noise as it was supposed to, and My TRX did nothing not even in tune mode. I tried the uplink frequency and didn't hear anything on either scanner. I am going to attach what I am receiving. This was at 07:46 a.m. this morning. I am also attaching one that is from 6/21/2017 at 11:55 P.M. for comparison. Any help you can provide will be greatly appreciated.
Ok, are there any visual clues that the TRX is receiving the signal when the 197 is producing noise but the TRX is mute?

Also, do you have any experience using DSD+? I'd be interested to see what's actually on that channel by way of comparison.
 

anelson5004

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I have no experience with DSD+, and at times the TRX showed an S with 3 signal bars when the 197 made the raw noise and at times the TRX did nothing. The TRX transmitted for 2 seconds a couple times today like it did on one of the attachments that is on here. I am at a loss as to why this is occurring given it was in the clear on the other attachment on 6/21/2017?

anelson5004
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