How to improve NXDN scanning

[AggieCon]

You are not ruining the thread at all. Working out the process using a specific example will help others go through the same process with their project as well.

 

[AggieCon]

Regarding skipped, go to browse objects. Go to each skipped frequency that you want to restore. Press the skip button, and it should be restored (small s instead of big S).

You can use the DFS Quick Import a few frequencies at a time. You can copy and paste certain lines. Also, you can delete the mobiles (i.e. the ones that say 45MO for this system) and then click the copy to clipboard button.

If you are using the list straight from my website, there could possibly be 7 objects in EZ Scan that could pick up the call:

1) FB repeater output on site 1
2) MO (duplicate) object that is the same frequency as (1), above
3) If the caller is nearby, the repeater input frequency
4) FB repeater output on site 2
5) MO (duplicate) object that is the same frequency as (4), above
6) FB repeater output on site 3
7) MO (duplicate) object that is the same frequency as (6), above

If you import only the FB2 frequencies, there will be less to sort through, making it easier to make sense of everything.

 

[troymail]

Hey Aggie - trying to get my channels in the right order. I'm a bit confused; when I scan through and it stops on a digital purr, I hit SKIP and it immediately lands on another digital purr. If I hit SKIP as many times as I can, I can usually get through 4 or 5 channels before the signal drops (2-3 seconds). Is this the correct method? Alternatively, if I let it scan through, it always stops on 4 specific channels out of the 52.

So because I can keep hitting SKIP and it immediately lands on several more channels, that seems to indicate the system is transmitting on several channels at once...that can't be right...what am I missing?

Trying to continue to test but it's just gone dead...of course

Thanks again!

If you're hearing alot of digital noise on multiple frequencies, it would seem they are not set correctly to be NXDN, etc. For any given system-site there should only be one control channel - unless the control channel is constantly jumping around. The rest should be NXDN but not necessarily voice... could be data too.

 

[AggieCon]

For any given system there should only be one control channel - unless the control channel is constantly jumping around. The rest should be NXDN but not necessarily voice... could be data too.

He meant to say site.

A unique object in the scanner is not necessarily a unique frequency. Multiple objects can have the exact same frequency, which would explain multiple "skips" per channel.

 

[theTastyCat]

You guys are absolutely fantastic - I really appreciate all the help.

Aggie, I think we might be talking about two different systems - this is the one I'm interested in:

Tennessee Homeland Security District 7 NXDN Trunking System, Various, Tennessee - Scanner Frequencies

But I get what you're saying about programming the different sites. Of the eleven or so sites, the one that would be closest to me 99% of the time is Pleasant View; might be worth also programming the system with Ashland City, since that is the county seat. Interesting to think that some traffic might be missed by not monitoring more than one site - different than in the ham world when repeaters are linked into a system.

Anyway! Aggie, based on the above system, how would you recommend I set up my scanlists?

Seriously, you guys are WAY patient - thank you!

 

[AggieCon]

We were talking about the same systems. If the information on the Radio Reference page is correct, then they are using frequencies from both the county and the Greer Communications licenses. Additionally, if the information on RR is correct, then they aren't even using some of the frequencies at the site that they told the federal government they would use it. The licenses for these systems are all over the place. FB2, FB6, FB8, frequencies utilized however they feel like it, etc.

Assuming the RR page is correct (e.g. someone used DSD+ to get everything correct), then program it as I described above, except use the frequencies listed for the applicable site on the Radio Reference page.

 

[theTastyCat]

On it - thank you!

 

[sibbley]

I love your URL. Thanks for posting those videos.

The scanner is showing full signal on a 125 watt system. DSD+ is doing just fine.

I am thinking that either the digital decoder is not properly decoding or the CPU is not recognizing the data as NXDN (due to bad software coding). I don't think there is much the user is going to be able to do fix this.

I think this is also why the control channels are tripping it up. Unlike a P25 or DMR control channel, it is not making sense of what it is receiving, so it doesn't know to ignore the frequency and move on. Likewise, it doesn't even know when it is on a voice call.

What a waste of everyone's time.

It only seems to be a problem with trunked systems. Maybe just the 9600 systems. There is not much in use full time around me, but what I've heard on the conventional side seems to work. Unfortunately, Norfolk Southern seems to be encrypted, at least what I've heard so far. PPL Electric sounds good with no drops on the conventional side, but it's rarely used. Also NXDN 4800.

Whether it's this particular system, I'm not sure since there is nothing else to check, but so far NXDN has been a bust for me.

 

[W4KRR]

It only seems to be a problem with trunked systems. Maybe just the 9600 systems.

Nope; it's a problem with NXDN 4800 systems as well. That's all we have around here AFAIK. I don't know of any conventional NXDN here either.

I would like to hear Whistler's position on the NXDN issues; whether they're working on a firmware update or not, or if they believe that it's a user programming issue or something else that's beyond their control.

 

[KD4YGG]

See this database entry...
Tennessee Homeland Security District 7 NXDN Trunking System, Various, Tennessee - Scanner Frequencies

I've noted in the miscellaneous text what DOES allow the TRX-1 to successfully decode (i.e. trunk track) this system.

Also used same method on Logan County, Kentucky (NXDN4800) and Todd County, Kentucky (NXDN4800).

It does work - just a lot of settings to program.
No IMPORT used; programmed by hand!!!


I didn't have any success with the Christian County, Kentucky (NXDN9600) system.
Wouldn't scan conventionally.
Couldn't get it to "trunk track".
Would decode if in Limit or Service search.
Appears to be NXDN9600 specific.

 

[KD4YGG]

NXDN RAN Code Discrepancy

I've noticed the following on NXDN trunking for NXDN4800 systems:

RAN Codes greater than 9 are DISPLAYED as DECIMAL.

However... you have to program them as HEXADECIMAL.

Confusing!!!

 

[W4KRR]

See this database entry...
Tennessee Homeland Security District 7 NXDN Trunking System, Various, Tennessee - Scanner Frequencies

I've noted in the miscellaneous text what DOES allow the TRX-1 to successfully decode (i.e. trunk track) this system.

Also used same method on Logan County, Kentucky (NXDN4800) and Todd County, Kentucky (NXDN4800).

It does work - just a lot of settings to program.
No IMPORT used; programmed by hand!!!

Just as an FYI: I programmed several sites of my local NXDN4800 system per your instructions. It does work, it just works poorly. The two main issues: missed replies, and conversations dropping out in mid sentence (This is while holding on a particular talkgroup). Once in a while I will actually get a complete conversation, but this is only about 20% of the time. The best results seem to be if I choose a smaller site with less frequencies, but the number of users allowed on the smaller sites is restricted.

I have tried various antennas, both rubber duck and outside base varieties, as well as driving around mobile to get closer to the various sites. It doesn't seem to make much difference. Signal strength doesn't seem to be the issue.

Also, I always program all my systems by hand (with the software); I never use the RR import.

 

[daredevil1]

Also, I always program all my systems by hand (with the software); I never use the RR import.

How do you program it manually with EZScan?

 

[daredevil1]

I would put each site into its own scanlist. There is a bug with EZ Scan. Sometimes they don't move scanlists correctly. If you go to the scanlist tab and open the scanlist setting, then close it again, sometimes that moves the frequency to where it is supposed to go.

This seems to be the problem I'm having.

http://forums.radioreference.com/wh...scanning-all-simulcast-sites.html#post2688976

How do I know which frequencies are assigned to a scanlist?

 

[troymail]

This seems to be the problem I'm having.

http://forums.radioreference.com/wh...scanning-all-simulcast-sites.html#post2688976

How do I know which frequencies are assigned to a scanlist?

If imported from the library, by default, they are all in the same scanlist.

To get each site into different scanlists, you need to "Duplicate" (button for it on the right side of the EZ Scan trunked systems tab) the system - one time for each site - lock out all but one site of the system in that copy, and then change the scanlist assignments for all of the talkgroup and radio ID objects to a different scanlist.

Keep in mind that some systems have sites that could be many miles from your location and the closest site to you - some may even be in other states. If you're just trying to get things working, you should focus on just the site that is closest to you and in range - lockout or delete the rest (or just don't import them).

 

[W4KRR]

How do you program it manually with EZScan?

You open up EZScan, type in the information you want, and then write the configuration to the radio.

 

[bg_nashville]

Just as an FYI: I programmed several sites of my local NXDN4800 system per your instructions. It does work, it just works poorly. The two main issues: missed replies, and conversations dropping out in mid sentence (This is while holding on a particular talkgroup). Once in a while I will actually get a complete conversation, but this is only about 20% of the time. The best results seem to be if I choose a smaller site with less frequencies, but the number of users allowed on the smaller sites is restricted.

I have tried various antennas, both rubber duck and outside base varieties, as well as driving around mobile to get closer to the various sites. It doesn't seem to make much difference. Signal strength doesn't seem to be the issue.

Also, I always program all my systems by hand (with the software); I never use the RR import.

I was in Robertson County today and using the updated DB info and programming suggestions resulted in only sporadic reception. Over the course of an hour, I wasn't able to hear a complete converstaion. Even monitoring all of frequncies conventionally didn't help.

 

[KD4YGG]

Those frequencies may not be in the correct order... didn't have a chance to test on those sites

My apologies

 

[AggieCon]

Regarding centralized (NXDN-C) vs. decentralized (NXDN-D), I suppose some FB8 licenses could use NXDN-D as well as NXDN-C. However, systems with FB6 only are not allowed to use a continuous control channel, so those should always be NXDN-D.

It would be interesting to start making note of the station class code for the NXDN system frequencies when we talk about them.

 

[sibbley]

Wednesday night I was able to gather more info regarding my troubled 9600 system. The system usually goes dead around 3PM and I don't hear anything again till around 5AM. With the ice we had Wednesday night from the day's rain, one talkgroup was active all night long.

During the day there are about 15 talkgroups going on and off all day long. It's kind of hard to keep track of which frequencies are being used for each. I'm not a DSD+ expert, I know enough to get myself hearing comms. Anyway, a couple salt trucks were out on TGID 491 of the system. Frequency 462.1250 was used by the company base radio while the trucks were on 464.0500. Just like back in the base/mobile days.

I was able to follow these comms with DSD+ using FMP24 and a scanlist of the system frequencies less the control channel. I had the TRX-2 tuned to 462.1250 in limit search and I was able to hear all the comms on that frequency. Some drop outs but not many. So I tuned the TRX-1 to 464.0500 in limit search to hear the other side of the conversations. That worked well too.

I'm not very knowledgeable about NXDN. Is this type of frequency switching normal? I know trunk systems will move through frequencies, but, I don't recall ever seeing the same TGID operating on two separate frequencies during the same communication. But, did I ever really pay this much attention before?

Neither my TRX-1 or TRX-2 will hear much of anything on these frequencies programmed either conventional or as a trunked system. I tried all kind of different things suggested in this thread, nothing really helps. I'm beginning to wonder if this is some kind of strange NXDN system that the Whistler just isn't capable of handling yet.