Can an LTR system be a single frequency?

radioprescott · #1 (**permalink**) 01-31-2009, 11:32 PM

There's discussion in the Arizona forum about single frequency LTR systems. Here's a summary:

Frequencies are licensed to the same entity, but at different sites.
Using LTRAnalyzer, the four freqs monitorable all report LCN=1
Each freq also always reports 'ATB' when there is voice traffic. There is no CWID
Freqs that have voice traffic use the same TG (0-01-001). Traffic has different unit identifiers and voices.
The four freqs monitorable do not simulcast.

Can an LTR system be a single frequency? And why would it be?

Here's the thread:
http://www.radioreference.com/forums...r-systems.html

N2DLX · #2 (**permalink**) 02-01-2009, 01:48 AM

Yup, LTR systems can be single-frequency. They're just using the LTR format as a unique squelch system, so someone can't stumble onto a PL or DPL tone and activate the repeaters. On GMRS where unlicensed users like to jump on repeaters and use them without permission, some repeater owners added an LTR controller so you need an LTR-capable radio with the right settings to even key up the system.

The reason you see one talkgroup indicates it's probably only one business using it, with no customers on it. 0-01-001 indicates they just need simple LTR signaling rather than an intent to run an SMR system.

Starcom21 · #3 (**permalink**) 02-01-2009, 02:19 AM

Yes, I ran into this with a small school district in Macoupin County IL, on VHF!

The recently changed the frequency to narrowband, but it's still an LTR!

Scanner Frequencies: Gillespie Community Unit School District #7 - VHF (Macoupin) Trunking System, Gillespie, Illinois

Unfortunately, I havent heard any talkgroups, even when attending a Varsity Football Game there.

But it had the idle bursts and have detected the CW-ID on a GRE Scanner.

Steveradio · #4 (**permalink**) 02-03-2009, 10:38 AM

I work for a security outfit in the Pocono area of Pennsylvania. They operate a LTR system using Kenwood TK3180 radios.

We have 5 channels to operate and someone told me our site could just be a single tower off the system but we can go on the other channels.

461.8500 R02 0-02-255 comes up when the identifier (CW - ID) goes and every couple of seconds when the controller is checking the frequency. Even on the mobile and portables we use that signal makes the radio light (receive light) turn green for a second or two. We utilize voice encryption and our TGID# 0-02-006 along with TGID# 0-02-003 which is another tower I am guessing. The other TGID# 0-02-081 which is another facility with the same input frequency.

My question is could this be off another big system since our dispatch has a office in Wilkes- Barre and we are about a half hour away. The other channels are different locations with different inputs?

Any easy way to find the rest of the frequencies for this system? That are is over whelmed with LTR systems...

If anyone can help out you can PM me as well, sorry to go away from topic to another area but the question is pretty much mine as well. They are fun to monitor once you figure them out...

Thanks
Steve

alphabravo1 · #5 (**permalink**) 02-03-2009, 11:44 AM

In my neck of the woods, there is a single site LTR system with about 10 users, plus one data user.

Works fine, plus allows roaming down "south" for users from the companies a few counties North.

Starcom21 · #6 (**permalink**) 02-03-2009, 02:41 PM

See: FCC Callsign Information for WPMZ343 on RadioReference.com

This is the owner of the LTR:
CONWAY, ROBERT J: CONWAY, THOMAS J

Name Conway LTR
FCC License: WPMZ343
Site Address: PIMPLE HILL
City: Blakeslee

Site Coordinates: 41.02647 -75.50603

Unidentified LCNS (these are the other repeaters possibly in use)
00 451.65000
00 451.72500
00 451.75000
00 452.10000
00 452.25000
00 461.85000
00 463.32500
00 463.67500

There also appear to be some remote links on these frequencies:
--452.45
--457.45
They are probably used to access the repeater from a remote area or act as receive sites. These will probably be CSQ or have a PL tone, but probably not a Talk Group ID.

There are also some simplex frequencies licensed (for portable to portable, mobile), these are low power:
--461.3875
--464.0375
--464.9625

These here are the licenses in the area, See the Industrial Electronics LTR on here:
Pennsylvania Trunking Systems

If you find anything please report back to me, or use the SUBMIT button on RadioReference database page. I am having your system added to the database:
Scanner Frequencies: Industrial Electronics/Conway LTR (Pocono Area) Trunking System, Pocono Area, Pennsylvania

Terry

Steveradio · #7 (**permalink**) 02-03-2009, 04:07 PM

I have tried pretty much all those frequencies from Blakeslee tower site since our one radio reads Ch.1 Blakeslee we use Ch.2 site to W.B. Ch.3 W.B. to Site plus a few conventional I would prefer not to list.

I get the controller on just about every one but no TGID's pop up since working evening and night shift guess they are not busy enough for me to catch activity.

Another scanner helper that way has been trying to help out as well and that's why my question was the same about have one frequency to the system. Could it be a separate channel just for that area and the main system up in Wilkes Barre or Scranton area?

Blakeslee is a pretty big mountain and we are at a higher elevation so I am a little confused with mapping it out. I also have a mix match of other systems from that area in the Stroudsburg region been trying to figure out?

Thanks Again
Steve

Starcom21 · #8 (**permalink**) 02-03-2009, 11:30 PM

What scanner are you using?

Steveradio · #9 (**permalink**) 02-04-2009, 10:01 AM

PRO 97 Radio Shack scanner, I need the LCN numbering correct in order to monitor the systems.

Again me and another friend mapped out two in Allentown which we have on RR database already... Just this is a new area for me and with all the systems in that area its confusing.

The Industrial Communications 800Mhz one and the FBN Wireless UHF Trunk system.

AlabamaRS · #10 (**permalink**) 02-04-2009, 01:23 PM

Quote:

Originally Posted by Steveradio

PRO 97 Radio Shack scanner, I need the LCN numbering correct in order to monitor the systems.

Again me and another friend mapped out two in Allentown which we have on RR database already... Just this is a new area for me and with all the systems in that area its confusing.

The Industrial Communications 800Mhz one and the FBN Wireless UHF Trunk system.

look here Mapping an LTR System - The RadioReference Wiki
Paul

Starcom21 · #11 (**permalink**) 02-04-2009, 01:54 PM

Mapping an LTR system with a Pro-97 CAN be very easy.

It just depends.

Enter the frequency in on a channel.
Change the mode it to "LTR".

If the is a repeater "idle burst" (every 10-15 seconds or so), the screen MAY display information, like 0-03-253 or 0-03-255.

It may OR may not display it everytime. Watch for a good 10 minutes or more. One time, the "key-up" may be a little longer and you may see an ID on the screen.

Or, you may hear the CW-ID, which you say you have already heard before.

Now, again, if it says 0-03-255 R03, then you know that that frequency is LCN 03.

Then go to the next frequency, and so on.

You may get no Idle-Bursts or data. You may or may not hear any traffic.
Traffic may be CSQ (no pl tone) therefore is may be an LTR Passport system, which can not be tracked. The frequency (if a PL or DPL tone) could be a community repeater (shared with different tones) or just a single user repeater.

Having a GRE made scanner like the Pro-97/Pro-2055 makes it much easier to figure out LTR systems. With Unidens you must go through a long, hard process to even attempt to get somewhere.

Hope that helps!

Terry