LTR Standard - System Voice: Analog - DSD+ Fast Lane 2.165 Newbie Questions

[AB9NN]

New to LTR. Experienced digital ham Extra Class. Reference page = https://www.radioreference.com/apps/db/?sid=6377
I see no red channels indicating Control Channels. Is this a set of trunked frequencies or analog or? I am running them in a ScanList for FMP24 and have had zero hits so far. I reviewed them in SDR#, albeit briefly, and there were no discernible signals there. I did see that they seem to be in a commercial band and there are signal pops and brief transmissions around them but not on them. Therefore I presume they are not control channels? I had thought that LTR was trunked but maybe that was just some flavor of it? Also - will FMP24 decode these and if so what mode to use? I see the following reference to LTR in the FMP.txt file but using Find it was the only one I could find:

12.5 kHz modes

PV
ProVoice
any other text string (analog, LTR, ...)

 

[mtindor]

DSDPlus is not an LTR decoder / trunker. Please read the various TXT files to see what DSDPlus does and does not do.

With that said, sure -- assuming the channels have traffic on them (most LTR systems are defunct now), you'll hear voice if you're using DSDPlus as a scanner.

There are no control channels on LTR systems. Trunking information is sent via low speed data during voice calls. Again, DSDPLus isn't going to decode that trunking information and is not going to trunktrack it. LTR is ancient history.

If you must dabble with LTR, see https://wiki.radioreference.com/index.php/Trunked_Radio_Decoders#LTR_Decoders .

Assuming there are still active talkgroups on that system, the analog activity could be on any one of those frequencies. So you are going to have to add all of the frequencies for a site to your DSDPlus scanlist and be patient and wait to hear audio. On that particular system, there is no indication that the LCN order for any of the sites on that system is even correct, or which sites are actually live. I think the last time a new talkgroup was added to that system in the DB was perhaps four years ago.

I would not be surprised if it didn't even exist anymore. If it does, then there will be analog voice on one or more frequencies of one of the sites.

 

[cg]

Often you will see the "beacon" or key up on each channel every 10 seconds that is common with LTR systems. In my area there is still a bit of LTR that is slowly being replaced with digital modes. These beacons are not unlike the XPT trunking beacons that are getting more common. SDR# can be helpful as the waterfall display makes seeing the key ups obvious, especially with slower scroll speeds.

While I realize you are using SDRs, many scanners can do the LTR and at least the Uniden 996 series can pick out the LTR activity if you do a search using Control Channel only mode.

chris

 

[DaveNF2G]

LTR-Standard is a decentralized form of trunking. There is no control channel. LTR-MultiNet has a subaudible control channel. LTR-PassPort is often overlaid onto a Standard system (at least in my area).

SDRTrunk is probably your best bet for tracking these systems.