Decipher this LTR system if you can..

[wv_mountaineer]

Here is a link to the FCC database for a LTR system...... ULS License - Industrial/Business Pool, Trunked License - WQDF534 - UNITED STATES STEEL CORPORATION - Frequencies Summary

This from what I am told is a LTR system and from the FCC site is listed as YG - Industrial/Business Pool, Trunked. I have input this info into my 396xt with no luck. Hopefully someone with knowledge can help me out by looking into it and telling me if at all this is truly an LTR system. I really don't know anything about LTR systems since I just got back into scanning back in Oct. before that I all knew was analog.

This looks to me like 2 antenna sites with 2 different station classes with 10 LCN's. I have looked into other LTR's that are known to work and they look nothing like this...

 

[mtindor]

There is nothing odd about that license. 10 frequencies. If it truly is an LTR system using frequencies on those licenses, then it'll have 1 to 10 active frequencies with LCNs assigned to them between 1 and 20.

The simplest thing to do is program all 10 frequencies into a bank conventionally. scan it. See if you hear activity that sounds like US Steel activity. At that point you'll know the system is active.

There is a document in the wiki that descriptions widely used procedures for determining LCN order. Basically what you seem to be asking is for somebody else to do the legwork. My guess is that somebody else would have already done the legwork if they weere so inclined. that leaves you with doing the legwork (determining proper LCN order so that you can scan the system in trunked mode and make use of the talkgroups, locking them out, enabling them, whatever).

You should read this link for starters:

Mapping an LTR System - The RadioReference Wiki

If it were me, and if I were using a Uniden like you are, I'd do this:

1. Program all 10 frequencies into a bank conventionally
2. Make note of every frequency that appears to be an active frequency in use by US Steel

3. Create a new LTR system
- program the most active frequency that you discovered from scanning conventionally into ALL 20 channels of the LTR system
- scan the system as an LTR system

When you hear a transmission while scanning that trunked system, you'll see on the display something like this:

0-HH-GG or 1-HH-GGG ( 0-01-30 or 1-15-190)
- where HH is the home repeater
- where GGG is the talkgroup

Typically, but not always, the home repeater (HH) will be the LCN associated with the frequency it stopped on.

So, if while scanning, it stopped on 464.35 and displayed 0-05-100, then:

HH = 05 (which likely, but not always means that the LCN is 05)

So then you know 464.35 is LCN5.

Go back into that trunked system and replace LCNs 1-4 and 6-10 with the second most active frequency that you had noted in your conventional search. Scan the system in trunked fashion.

When a transmission is occurring on that second most-active frequency that you entered in, make note of the HH again. If that HH shows 09, then LCN9 is associated with that second most-active frequency.

Edit the trunked system and change 1 through 4, 6 through 8, and 10 to the third most-active frequency.

Repeat add nauseum.

It's actually pretty fun. I have seen people [perhaps you, perhaps someone else] wanting the information regarding this trunkeed system in the past. Instead of waiting for somebody to post it, it is better for you to figure it out yourself. If it's a busy system, you can figure out a lot about it very quickly.

A few things to keep in mind:

1. If the system isn't very active, it coudl take significantly longer to figure out
2. Just because 10 frequencies are assigned to the license, don't be surprised if not all of 10 of them are in use. Even if all 10 are actively a part of the trunked system, some of them may only be used when the home repeater for a certain talkgroup is in use, in which.
3. HH referenced above is most often indicative of the LCN associated with that frequency, but not always.

Mike

 

[mtindor]

The FB2 and FB8 notations could be deceiving on the license. You can't always go by those designators. But if you do, then assume FB8 is some sort of trunked system, often LTR, and that FB2 just happen to be conventional frequencies assigned on the same license.

But you can also assume that one or the other could be a mistake, since I've often seen obvious mistakes that passed through FCC scrutiny on a license.

Another thing to keep in mind... LTR trunked systems do not use CTCSS/PL or DCS/DPL. If you program those frequencies in conventionally and then your scanner reports tones on them in conventional mode, they don't belong to an LTR trunked system.

Mike

 

[n3obl]

Have to be careful with the PL tones.. Can be more than one repeater on a freq?

Say an LTR system and also a PL system.

Dead giveaway is the tx chirps.

Frank

 

[Jay911]

What I do is create one system in my scanner for each frequency. In your case you'd create 10 systems, all with the same system quick key, with all the LCN positions filled with the same frequency. (One system has 451.875 in all 20 slots, the next has 452.15 in all 20 slots, etc.) Then you follow the same rules as above ... turn it all on and watch. If system 1 (which has 451.875 as a frequency) lets you hear traffic on 0-04-002, that means 451.875 has a very good chance at being LCN #4. Repeat until you get all the frequencies mapped out. Optionally, when you figure out a frequency, go into all the duplicate systems and replace that LCN with the right freq.

 

[radiofan1]

Some LTR controllers can be programmed to operate in a mixed mode whereas they'll repeat conventional w/ PL tones as well as act as an LTR trunked channel. Trident Raider for one.

 

[fwradio]

On private trunking licenses:

FB8 designates exclusive channels - no monitoring required. Typically used for home channels.
FB2 designates non-exclusive - those must be monitored, typically used for goto channels, not home.

If the system is constructed, all channels may be built out as trunked.

 

[Jay911]

On private trunking licenses:

FB8 designates exclusive channels - no monitoring required. Typically used for home channels.
FB2 designates non-exclusive - those must be monitored, typically used for goto channels, not home.

If the system is constructed, all channels may be built out as trunked.

I wish Canada's database was as thorough as that.. there are things in the FCC db that are a thousand times more descriptive than Industry Canada!

 

[wvscanner]

Have to be careful with the PL tones.. Can be more than one repeater on a freq?

Say an LTR system and also a PL system.

Dead giveaway is the tx chirps.

Frank

The tx chirps is meaning what? I have a few freq. that has it

 

[n4yek]

TX Chirps (key up's) are a dead give away that the frequency you are monitoring is part of an LTR system.

But, not all LTR systems have them enabled, the system here locally to me does not have the chirps enabled. You never hear them periodically key up when monitoring with an older scanner.

 

[silverbk]

The tx chirps is meaning what? I have a few freq. that has it

The chirps are the beacons on the system that the portables and other radios listen for to determine if they are in range. Like another poster said sometimes they are enable and sometimes they are not.

What you are listening for is a key up every 30 seconds or so on the home channel.

The easiest way to decode these systems is to run LTR analyzer on the output of a tapped scanner. Every time a user keys up you will see all the data. ie groups and channels

Most of these systems are set up pretty plain jane, and with standard settings you should be able to decode at least some of the users on the system.

 

[wvscanner]

I had run LTR analyzer on that channel in the past for 24hrs. When I submitted the log to help me understand it it was told that it had nothing but junk in it. The signal was very decent coming off on a tap scanner. I did notice that this freq. only did it at times on the chirps, but it also had a pl detected on another scanner. Also noted that this one freq. only does it when someone keys up, no other times it does it.