NXDN one Frequency system fails

[ScanHen]

Around 20 kilometers from here there is a NXDN repeater active. When I configure the frequency in a conventional system it works fine. In contrast to a DMR repeater frequency which works fine in a 'DMR one frequency' system the NXDN frequency does not work in a 'NXDN one frequency' system. I also tried a NXDN Trunk system but this also failed. In all these systems the correct RAN was configured.
My question: why does the 'NXDN one frequency' system not work with a NXDN repeater (with one frequency)?

 

[buddrousa]

If you are trying to follow a NXDN TRUNKING SYSTEM.
#1 You need all frequencies used in the system.
#2 You need to enter all the LCN's for all frequencies used.

If you are using NXDN 1 frequency trunking to listen to a Conventional NXDN Repeater it will work.
20 miles what are you using for an antenna?
You can not receive 20 miles on the back of set antenna.
I have 6 536's they all receive NXDN 20 to 30 miles with an 30 foot outside antenna.
I have 1 SDS200 it receives NXDN 20 to 30 miles sharing the same antenna system.
I have 2 SDS100's they receive NXDN 20 to 30 miles sharing the same antenna system.
I have 9 996P2's they receive NXDN 20 to 30 miles sharing the same antenna system.

 

[mtindor]

Around 20 kilometers from here there is a NXDN repeater active. When I configure the frequency in a conventional system it works fine. In contrast to a DMR repeater frequency which works fine in a 'DMR one frequency' system the NXDN frequency does not work in a 'NXDN one frequency' system. I also tried a NXDN Trunk system but this also failed. In all these systems the correct RAN was configured.
My question: why does the 'NXDN one frequency' system not work with a NXDN repeater (with one frequency)?

I don't have an immediate answer. But you should read htrough this thread thoroughly, as many people in the thread have chimed in about issues with OFT P25, OFT NXDN and OFT DMR.

NXDN One Frequency vs Conventional NXDN Programming

I've been working on a couple new NXDN systems here and have noticed something on both the x36hp and SDS 100 while programming. When I program the system as a One Frequency NXDN and add the TGID 0, both scanners seem to miss alot of transmissions. When it's programmed as Conventional NXDN...

forums.radioreference.com

You won't be able to reply in that thread, but some of the findings / answers may be helpful to you.

In your NXDN OFT, are you in ID SEARCH mode? If you are in ID SCAN mode, make sure to add TGID 0 to the system.

Mike

 

[R0am3r]

If you are trying to follow a NXDN TRUNKING SYSTEM.
#1 You need all frequencies used in the system.
#2 You need to enter all the LCN's for all frequencies used.

There are exceptions to these rules. NXDN Direct Frequency Access (DFA) systems use a control channel that passes along the frequencies for voice channel information. The challenge is finding all of the frequencies for the site because control channels sometimes propagate to other site frequencies. I use DSDPlus FL to map out these sites in-lieu of my Uniden scanners. Thanks to DFA, no LCNs are needed! Apologies for flogging this horse.

 

[mtindor]

There are exceptions to these rules. NXDN Direct Frequency Access (DFA) systems use a control channel that passes along the frequencies for voice channel information. The challenge is finding all of the frequencies for the site because control channels sometimes propagate to other site frequencies. I use DSDPlus FL to map out these sites in-lieu of my Uniden scanners. Thanks to DFA, no LCNs are needed! Apologies for flogging this horse.

Isn't this thread about One-Frequency Trunked? I doubt there is DFA on conventional NXDN. This person is specifically wanting to copy a single channel system (and it probably isn't even a compositive NXDN trunked system with a control channel but rather a simple conventional NXDN frequency). I'm guessing the person wants to program a simple NXDN repeater as OFT so as to be able to have any aliases revealed. Just a guess.

Mike

 

[hiegtx]

Around 20 kilometers from here there is a NXDN repeater active. When I configure the frequency in a conventional system it works fine. In contrast to a DMR repeater frequency which works fine in a 'DMR one frequency' system the NXDN frequency does not work in a 'NXDN one frequency' system. I also tried a NXDN Trunk system but this also failed. In all these systems the correct RAN was configured.
My question: why does the 'NXDN one frequency' system not work with a NXDN repeater (with one frequency)?

The thread that Mike linked has an extensive discussion of this issue.

In order for an OFT system to work successfully, there are several steps that need to be taken.

Enter the correct frequency, and if known, enter the correct RAN.

Be sure that the OFT system is set for 'ID Search' unless you are positive about any TGID being used.

The OFT System must have a Department. Otherwise, the scanner will ignore it. Also, that Department must include a talkgroup. If you do not know what talkgroup is used, then enter a place-keeper talkgroup, such as imply '1'. If you are positive about the TGID, enter it. Note that leaving the OFT system set to use ID Search will also enable you to capture any other talkgroups on the same frequency.

Note that even though NXDN is a narrow signal, I have better results if I set modulation to FM, not 'auto' or 'NFM".

 

[werinshades]

The thread that Mike linked has an extensive discussion of this issue.

In order for an OFT system to work successfully, there are several steps that need to be taken.

Enter the correct frequency, and if known, enter the correct RAN.

Be sure that the OFT system is set for 'ID Search' unless you are positive about any TGID being used.

The OFT System must have a Department. Otherwise, the scanner will ignore it. Also, that Department must include a talkgroup. If you do not know what talkgroup is used, then enter a place-keeper talkgroup, such as imply '1'. If you are positive about the TGID, enter it. Note that leaving the OFT system set to use ID Search will also enable you to capture any other talkgroups on the same frequency.

Note that even though NXDN is a narrow signal, I have better results if I set modulation to FM, not 'auto' or 'NFM".

I was the OP previously, and despite my attempts to resolve it, even sending in debug files to UPMan at the time, it was diagnosed as too weak of a signal. The system I was attempting to monitor was a rental car company which was within a mile of my location.

I went as far as taking my SDS100 a block away, identical set up and didn't have any luck. I submitted another debug file from my SDS100, and never received a response back. While a rental car company isn't the most exciting listening, trying to decipher a OFT NXDN system was the goal.

I've only encountered two OFT NXDN systems and had no luck. As hiegtx mentioned, a Department is needed, but I still ran it in ID search and in both NFM and FM mode without any improvements. My "unscientific take-it-for-what-its-worth opinion" is the x36hp/SDS series of scanners have a difficult time locking onto Talkgroup 0 (which seems to be common in the two systems I monitored). The reception was sporadic at best, and when compared to another scanner running in conventional mode, I missed alot of transmissions. I base this on OFT MotoTRBO systems, which use TGID 1 in some instances. In that case, the scanners performed very well.

I have no other suggestions other than what's been mentioned. If we ever see another firmware upgrade, hopefully this will be addressed.