NXDN Update Now Available!
- Thread starter WhistlerWendy
- Start date
- Status
milcom_chaser
Member
- Joined
- Jul 4, 2010
- Messages
- 982
Today I'm going to make this video as I'm home with some wonderful upper respiratory ailment. One thing I hadn't considered before with this, and I wonder if it applies. Take a look at the accompanying screenshot. Notice the gap between channel 497 and channel 518, then to 542, and then the blank 556.
I've confirmed this layout now on three different DSD+ setups. I didn't give it a lot of thought yesterday as I thought it might have been some residual junk left over from monitoring another DSD+ system (Network 178 Site 3 in Plymouth) that uses some of the blank channels. This system never sends traffic to these channels. It makes me wonder if I should program the Whistler for this site in the following manner:
1. 452.2125
2. 452.6500
3. 461.2000
4. blank
5. blank
6. 461.4625
7. blank
8. 461.7625
9. blank
Didn't we have to do this with LTR systems on the old GRE scanners? It's been a long time and I'm not sure, but I wonder if that's part of the puzzle.
Stay tuned!
I've confirmed this layout now on three different DSD+ setups. I didn't give it a lot of thought yesterday as I thought it might have been some residual junk left over from monitoring another DSD+ system (Network 178 Site 3 in Plymouth) that uses some of the blank channels. This system never sends traffic to these channels. It makes me wonder if I should program the Whistler for this site in the following manner:
1. 452.2125
2. 452.6500
3. 461.2000
4. blank
5. blank
6. 461.4625
7. blank
8. 461.7625
9. blank
Didn't we have to do this with LTR systems on the old GRE scanners? It's been a long time and I'm not sure, but I wonder if that's part of the puzzle.
Stay tuned!
Attachments
Here's a first video of the comparison. The scanner is programmed with just the one system, and with the blanks as shown in the previous screenshot; this apparently makes no difference. Dwell time is set to 2 seconds, and just a talkgroup wildcard is being used.
https://www.youtube.com/watch?v=oYos_pjx1xI
https://www.youtube.com/watch?v=oYos_pjx1xI
Seeing as we can't set the channel in Whistler--and since DMR also does not trunk track--I'm pretty confident the TRX does not trunk track NXDN. It just does round robin with each frequency looking for a hit. No difference than scanning as a conventional object, except it allows an easier way to program talkgroups of (dis)interest. Some NXDN systems don't even use the scale shown above to assign the channels, they just do 1, 2, 3, etc., so if you think a scanner is magically figuring a lot of complicated, nuanced settings out on its own, well, probably, it is not... It's kind of like how the TRX supports the source alias. Oh, wait, does it?
where is the squelch set on the units?
Squelch is set completely counter-clockwise. I already ranted about that in another thread. If this scanner were to be used just for NXDN and it actually made a difference where it was set (which as far as I can tell it absolutely does not) that would be great. In the real world I'd be using this for more than just NXDN, so having the squelch wide open would not be in my best interests.
I think Aggie is right. I don't think this scanner trunk tracks. But...it DOES decode NXDN and that IS what Whistler promised. I'm sure users that have agencies that went to conventional NXDN are thrilled, and they should be, because the audio quality is superb.
But, right now...that's where it ends.
DonS
Member
That's pretty obvious, based on the relatively constant display of the inverted 'S' icon (to the right of the signal bars).
That's bad. That icon means "squelch open, expecting a digital signal, haven't found it yet." If there's no NXDN signal present, the scanner will be spending time looking for something that isn't there. All the time that 'S' icon is displayed is time the scanner is wasting looking at noise. The only exception to this rule is if you see a brief flash of the 'S' icon, immediately replaced by 'T'.
It doesn't really "trunk track" DMR either. At least not by monitoring the control channel. I think that was a given. But for me, it tracks DMR (in it's own way) very well keeping up with the Uniden, sometimes a little better even.
The problem is, that the S constantly appears pretty much regardless of where the squelch is set. To me, THAT'S bad.
I've got the squelch fully clockwise now as I type this and the S is flashing exactly the same as it does with it fully counter-clockwise.Any suggestions as to why that might be? I'd be happy if it was something I was doing wrong.
slicerwizard
Member
Then how did they end up in the channel display?
No, that wouldn't make any sense. Blank channels aren't going to do anything for you. Just program the known channels.
Upon further review it occurs to me that perhaps this scanner is easily overloaded in the UHF frequency range of 450-470 MHz. I am in a pretty high RF environment with an abundance of strong signals in that range. If that's what's keeping the squelch circuit busy then I'll never find a solution.
That said though, it's interesting that the $20 dongle, which has zero front end filtering and acts as a receiver in the DSD+ setup and is connected to the same tower mounted external antenna, does not suffer the same fate. Maybe the TRX-1 I have is defective? I can drag out the TRX-2 Jeff sent me and set that up as a comparison, but it won't be today.
I'm trying different combinations of antennas, attenuation, etc., but can't find a balance that works. If I attenuate or crank the squelch too far to the right I hear nothing, yet I know I'm working with strong signals. Attic mounted antennas, UHF rubber duck antennas, etc., don't seem to make much if any difference and outright don't recover the audio that the dongle is merrily hearing.
That said though, it's interesting that the $20 dongle, which has zero front end filtering and acts as a receiver in the DSD+ setup and is connected to the same tower mounted external antenna, does not suffer the same fate. Maybe the TRX-1 I have is defective? I can drag out the TRX-2 Jeff sent me and set that up as a comparison, but it won't be today.
I'm trying different combinations of antennas, attenuation, etc., but can't find a balance that works. If I attenuate or crank the squelch too far to the right I hear nothing, yet I know I'm working with strong signals. Attic mounted antennas, UHF rubber duck antennas, etc., don't seem to make much if any difference and outright don't recover the audio that the dongle is merrily hearing.
I don't know how they wound up there. As I stated, I was puzzled by this and tried two other DSD+ setups. They all produce the same results.
As for the second suggestion I discovered it made no difference after trying it. It was a grasping at straws effort. I'm trying, and I don't see a lot of other input and experimentation at this point.
Maybe as I said in the last post it's just me due to RF environment issues. Who knows, and I'm beginning to care less.
Scott. I'm monitoring that same system, but likely on different sites. For whatever reason, the control channel data shows 501, 514, 536, and 556 on all three sites I can receive. The odd thing is that I don't see any activity on those channels with the frequencies programmed in. You might be on to something by skipping them. OTOH, I have posted the frequencies for those channel numbers on Scan-ne, so maybe you can try programming the frequencies in and see what happens.
From what I can tell, the black S is always open when NXDN is programmed as trunked. When programmed as conventional, the squelch setting applies.
Correct me, please, if you have NXDN programmed as trunked and when you are scanning just a single NXDN system the black S is not constantly present/blinking.
Overall, these radios handle digital voice much better with the squelch all the way to the counter-clockwise position.
Correct me, please, if you have NXDN programmed as trunked and when you are scanning just a single NXDN system the black S is not constantly present/blinking.
Overall, these radios handle digital voice much better with the squelch all the way to the counter-clockwise position.
If the company could hire a technical writer to consult with the designer and then explain exactly how it functions and how to make it work, that would really be, well, expected.
I suspect the radio tries to demodulate and send data to the decoder all the time when programmed as trunked (i.e. regardless of whether or not there is a signal), with a dwell time to determine how long to sit on a frequency. I could be wrong, but I think this is how it was programmed to work.
As I have tried the hardest to promote, program these frequencies as conventional unless there is a compelling reason to do them as trunked. I even made a website to make it easy to accomplish this.
I suspect the radio tries to demodulate and send data to the decoder all the time when programmed as trunked (i.e. regardless of whether or not there is a signal), with a dwell time to determine how long to sit on a frequency. I could be wrong, but I think this is how it was programmed to work.
As I have tried the hardest to promote, program these frequencies as conventional unless there is a compelling reason to do them as trunked. I even made a website to make it easy to accomplish this.
troymail
Silent Key
I disagree for NXDN trunk mode -- with the squelch completely CCW, the radio is spending a tremendous amount of time trying to process static. If you have a fairly strong signal, setting to 12 o'clock is better (if not further clockwise).
Ultimately, I believe you want to see the 'S' as little as possible.... that is, I believe 'S' means "I'm seeing something but it doesn't look like anything useful (to decode) - yet"
Last edited:
Thanks for confirming that.
I've reprogrammed them as conventional and locked out the trunking data. My window of opportunity is by-and-large closing with this system due to the majority of its users going home around 5 EST or so, but from what little I've seen thus far it continues to miss traffic. I can confirm that the S does not appear at all in conventional mode, even with the squelch cranked fully counter-clockwise.
I don't think there's much else I can contribute to this so I'll sit back and let others comment unless I get specific questions, comments, insults.
Of course I hope improvements will be made as time passes. At some point in the near-future I'll have to return these scanners to Jeff. I thought NXDN might be easier for them to figure out than DMR as at least on the surface it has a similar appearance to a Motorola system in the way it acts, but I obviously have little knowledge of its underbelly.
- Status
Similar threads
