This is why it is important to remember the FCC is only a starting point. I can think of several systems (including this one) that don't have every licensed frequency in use. It helps to monitor control channels if possible and see just exactly how many channel grants are being sent out.
NXDN in NC
- Thread starter GamecockSJ
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troymail
Silent Key
As we've probably discussed many times, the FCC license data isn't always going to represent the systems/sites exactly. These "extra" frequencies could just be for future growth and authorized so they don't have to go back and make a new FCC request. Interestingly, however, the required "build out" notification in 2015 said that frequency was completed when other were completed.
The FCC license data contains both lots of errors and lots of "future planned" things (i.e. Phase 2 on VIPER, NXDN on Norfolk Southern, etc.)... I still laugh when I see one of my local users (who just renewed their license) which (still) says they are DMR but they are actually NXDN....
AlphaFive
Member
Mills River
Roger That, to both of you, take care
Roger That, to both of you, take care
Here is what I have so far on the Winston Tower Fleet Talk site, thanks to the LCN finder on my BCD436:
464.8875 LCN 792
461.375 LCN 511
462.325 LCN 587
463.3125 LCN 666
According to a submission to the database 464.9125 is used on the Winston Tower. However, the LCN finder never confirmed the LCN listed (794) and I've yet to hear any activity on this frequency conventionally. I'm thinking it is no longer associated with this site based on the frequent radio traffic coming across the site?
It also appears the NC & SC site are indeed linked. Heard radio techs on TG 1 asking for radio checks. One tech was in Columbia,SC and the other was in Mount Airy,NC.
464.8875 LCN 792
461.375 LCN 511
462.325 LCN 587
463.3125 LCN 666
According to a submission to the database 464.9125 is used on the Winston Tower. However, the LCN finder never confirmed the LCN listed (794) and I've yet to hear any activity on this frequency conventionally. I'm thinking it is no longer associated with this site based on the frequent radio traffic coming across the site?
It also appears the NC & SC site are indeed linked. Heard radio techs on TG 1 asking for radio checks. One tech was in Columbia,SC and the other was in Mount Airy,NC.
troymail
Silent Key
I heard a similar series of voice calls some time ago between a user in Supply NC and somewhere near Rock Hill or York, SC (if I remember correctly).
OK so let me help with some info here. I have spent a while doing my research and seeking out info on this system.
First off I keep seeing people say on RR "there is not band plan" for NXDN. That'a a bit untrue. Yes it is possible to setup all kinds of channel number plans but this system *so far* uses the standard UHF plan. Which I recommend reading this thread about:
https://forums.radioreference.com/voice-control-channel-decoding-software/298075-understanding-nexedge-trunking.html
In short NXDN broadcasts channel numbers OTA as we've all seen. Here is the *standard* plan:
So with DSD+ and a SDR dongle it's actually very easy to figure out the details for a site on FleetTalk. (so far). If you have it then run it for a day or so, especially at busy times like weekdays, and then you should have a list of channels. Just plug that info into the formula above and in most cases you'll have all your frequencies.
The NC and SC FleetTalk systems are both 219, that we know, they are both linked. When you see a group where all the RIDs are "7" then that is coming across from one system to another. They are two systems of 30 sites each.
What would really be helpful to get this listed right is for anyone who can to use DSD+ and some time and monitor the control channels to get the frequency lists. Then use that formula to come up with the frequencies. Then AFTER that go ahead and run those frequencies through the FCC database to see if any license match up.
Another nice thing that anyone who has used a dual SDR setup with DSD+ will have seen is that NXDN sends radio aliases over the voice channels. So if you're tracking it with DSD+ you can see the names of the radios and that helps to nail down who may be talking or at least what company it might be.
Hopefully some or all of this helps and keeps the discussion going. I don't want to step on any toes or ruffle any feathers. Just want to get as much info out there as I can.
First off I keep seeing people say on RR "there is not band plan" for NXDN. That'a a bit untrue. Yes it is possible to setup all kinds of channel number plans but this system *so far* uses the standard UHF plan. Which I recommend reading this thread about:
https://forums.radioreference.com/voice-control-channel-decoding-software/298075-understanding-nexedge-trunking.html
In short NXDN broadcasts channel numbers OTA as we've all seen. Here is the *standard* plan:
So with DSD+ and a SDR dongle it's actually very easy to figure out the details for a site on FleetTalk. (so far). If you have it then run it for a day or so, especially at busy times like weekdays, and then you should have a list of channels. Just plug that info into the formula above and in most cases you'll have all your frequencies.
The NC and SC FleetTalk systems are both 219, that we know, they are both linked. When you see a group where all the RIDs are "7" then that is coming across from one system to another. They are two systems of 30 sites each.
What would really be helpful to get this listed right is for anyone who can to use DSD+ and some time and monitor the control channels to get the frequency lists. Then use that formula to come up with the frequencies. Then AFTER that go ahead and run those frequencies through the FCC database to see if any license match up.
Another nice thing that anyone who has used a dual SDR setup with DSD+ will have seen is that NXDN sends radio aliases over the voice channels. So if you're tracking it with DSD+ you can see the names of the radios and that helps to nail down who may be talking or at least what company it might be.
Hopefully some or all of this helps and keeps the discussion going. I don't want to step on any toes or ruffle any feathers. Just want to get as much info out there as I can.
troymail
Silent Key
Still seeing pretty poor performance on both a conventional NXDN channel as well as a NXDN single frequency trunk system (SC Fleettalk - Supply).
I'm hearing voice activity on both on the TRX-1 this morning and the 436 is catching none of it.
I tried changing the SC Fleettalk on the 436 from Auto to FM - isn't helping. I see (at most times) 4 bars of signal on the 436 and yet, it doesn't stop on the activity. The 436 is also display random things like NX4, NX9, NX0, and IDS while scanning.
EDIT: and now a few minurtes later, they are both picking up for the most part but not 100% of the time... it almost seems like the 436 needs to "settle in" ("I'll get to it when I get to it") if you move the radio or change anything....weird.
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troymail
Silent Key
Monitored the Burgess site of SC Fleettalk for about 4+ hours last evening... The only active frequency I saw for the site was 462.7375.
Ran LCN finder on the 436 the whole time and it only found 1 of 6 listed site frequencies - 620 for 462.7375
Ran LCN finder on the 436 the whole time and it only found 1 of 6 listed site frequencies - 620 for 462.7375
Some adjustments are coming for that site. For now just treat it as a single channel site on 462.7375.
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troymail
Silent Key
More NXDN coming to the Southport area?
ULS License - Industrial/Business Pool, Conventional License - WRAS724 - TTX
ULS License - Industrial/Business Pool, Conventional License - WRAS724 - TTX
Those emission designators look like analog and P25. Don’t have my cheat sheet in front of me but usually 11K is FM, 8K is P25, 7K is DMR, and 4K is NXDN.
But I’d keep an ear out to confirm.
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troymail
Silent Key
The 6.25 uses the 4K which is what I see most. But you’re right too. Could be.
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NYRHKY94
Member
Thanks for the Southport NXDN tip Troy 
Mike
Mike
Here are a few TGs I've heard so far on the Fleet Talk system. Nothing really exciting yet unfortunately:
119-Trucking/contracting Co
123-appliance delivery Co
134-Fire alarm/security contractor
152-Trucking/contracting Co
164-?
199-Security Co
483-school busses
119-Trucking/contracting Co
123-appliance delivery Co
134-Fire alarm/security contractor
152-Trucking/contracting Co
164-?
199-Security Co
483-school busses
troymail
Silent Key
yet? I wouldn't get my hopes up for exciting ....
troymail
Silent Key
Watching (even more) closely the Brunswick Transit channel - programmed as conventional NXDN96 ... holding on the talkgroup.... still trying to see if I can improve reception...
For some reason I think I've seen something related to this long ago but while holding with the 436, the radio is obviously detecting and stopping on the data bursts (i.e. not voice transmissions). I've watched for a bit now and see the radio/unit IDs displayed on the scanner in a consistent rotation of nine IDs. When these data bursts go active, they seem to last a few seconds (2-3?), the radio also shows NX9, and nothing is heard. At one point, I did receive two voice calls from 2 of the units and then the cycle of non-voice activity pretty much picked right back up again. The cycle begins again roughly every 3 minutes (would probably vary for less than or more active units).
Given the cycle/pattern, I assume this is GPS/location or other vehicle data being transmitted ... which is fine...
However, I have no idea why the scanner would waste time stopping on this activity.....
troymail
Silent Key
More play -- I had SC Fleettalk programmed with no TGIDs but ID Search enabled.... poor reception/performance while scanning this and Brunswick Transit.
I created an entry for a known "regular" talkgroup and have been HOLDing on that talkgroup for a while -- this seems to make a big difference .... but which thing made that difference?
- add a "department" to...
- add a specific a TGID?
- HOLDing on that TG / not scanning other systems?
- not running/scanning in ID Search mode (effectively since I'm HOLDing)?
If it can receive the talkgroup when holding on that talkgroup, you'd think it would/should do the same when scanning (not holding)....you'd think.
Idunno
Any NXDN in the RDU area?
Hey folks,
Bringing this thread back around; looks like NXDN is primarily used in either WNC or out towards the coast, from what I can tell. Is anyone in the Triangle area monitoring any NXDN?
Hey folks,
Bringing this thread back around; looks like NXDN is primarily used in either WNC or out towards the coast, from what I can tell. Is anyone in the Triangle area monitoring any NXDN?
AlphaFive - According to what I have found thus far, LCN1 for the NXDN system at KAVL appears to be 159.1875. I can only find 3 repeater frequencies total in the FCC record. How did you determine that this might be a 6-frequency system?
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