LTR TGID Question

[mtindor]

In monitoring LTR systems, in x-yy-zzz , yy is the LCN, yes? And if so, then when somebody posts an identified TGID of 0-05-105 on a system that has 8 frequencies with LCNs scattered between 1 and 20, the actual TGID is going to show up differently depending upon the channel that the user shows up on right?

i.e.

0-01-105
0-02-105
0-03-105
0-04-105
0-19-105

Those are all the same talk group but just active on a different LCN, are they not? If so, then the actual ID that one would record is just the last number, 105, no?

This is so confusing.

Mike

 

[captclint]

TGID does not change when it goes to another open channel. That is what makes identification of the ACTUAL LCN/freq so difficult when a 0-05-008 shows up on LCN 01. It still shows up as 0-05-008, not 0-01-008, Furthermore, 0-01-008 is a totally different user than 0-05-008, so each LCN can have up to 254 users.

 

[mtindor]

TGID does not change when it goes to another open channel. That is what makes identification of the ACTUAL LCN/freq so difficult when a 0-05-008 shows up on LCN 01. It still shows up as 0-05-008, not 0-01-008, Furthermore, 0-01-008 is a totally different user than 0-05-008, so each LCN can have up to 254 users.

Hmm, ok. I understand. Let me paint a scenario.

- have not heard anything on an LTR system for an hour
- suddenly 0-03-080 pops up on 472.3375
- system goes quiet (known from scanning freqs conventionally)
- later on 0-03-080 pops up again on 472.3375

The Wiki document about mapping LTR says that a TG will always use its home repeater by default unless it is busy. So is it safe to say that as long as there is absolutely no other traffic on the system except for the one user talking, then that one user must be talking on their home repeater - which would then equate to 472.3375 being LCN 3 (by virtue of 0-03-080 always showing up) ? Just started really monitoring an LTR system today, and that's the method I'm using to try and determine LCN order. I believe I've confirmed two LCNs today by seeing that when the system is otherwise silent, a particular 0-02-xxx ID is always talking on 472.1875 and a particular 0-03-xxx is always talking on 472.3375, making their respective LCNs 2 and 3 - correct?

Mike

 

[captclint]

I think you are generally correct about your assumptions. Sounds like a low activity system, so that will make it easier to find the main LCN's, but much harder to find the GOTO channels. Keep at it, and you will be rewarded with some interesting and frustrating experiences.

 

[mtindor]

I think you are generally correct about your assumptions. Sounds like a low activity system, so that will make it easier to find the main LCN's, but much harder to find the GOTO channels. Keep at it, and you will be rewarded with some interesting and frustrating experiences.

I'm hoping, both good and bad. Just getting my feet wet. So far it has been relatively low activity (no simultaneous conversations). I've seen probably ten different TGs on only two channels. It may pick up on a Monday. School buses and trash haulers seem like the majority thus far.

Thanks.

Mike

 

[WayneH]

Your yy bits are the group's home repeater. Each repeater in an LTR network has its own set of groups (1-250) programmed into it.

The LTR forum has a ton of information in it. I'd recommend browsing through it some time.

Also, please remember to look for the appropriate forum before posting your message. Thanks.