Could anyone tell me Is that a LTR-system?

[fuctea2k]

There is many guys using MTX-LS and some E.F.Johnson duplex mobile radio around my city. but I can't find Control Channel belongs to that system. I can even hear they make duplex phone calls, and with a "a DTMF tone and Two beep" hang-up signalling, it is different from all motorola system in my city. I just want to confirm that there is a LTR system in my city which I haven't know, and how to trace the system?






Thank you!
Wang

 

[cg]

there is no control channel for LTR, instead the control info is transmitted as subaudible signal on each frequency. Listen for a "key up" of the repeater every 1 to 10 seconds. That is an indication of a LTR system. As for figuring out the system, look in the LTR postings as this subject has been covered many times.

chris

 

[SCPD]

Hi WH,

Some folks have been using a trunker-like program called LTrunk or LTRTrunker to decode and display the control information on an LTR system. Search past threads in the Software decoding forum.

You will need a radio with a discriminator tap (remember that one?) and a low pass audio filter (150 hz?). Search the software decoding forum for Info on the low-pass filter.

The channel numbering of LTR systems is similar to EDACS so you have to map out channel numbers to actual frequencies. The LTR system may also have multiple "home" channels. These are like control channels but can carry voice at the same time.

-rick

 

[fmon]

Two beep" hang-up signalling, it is different from all motorola system in my city.
Thank you!
Wang

If inconclusive that the system is LTR, beeps at the end of a transmission is an indication that this could be EDACS and you can often hear EDACS voice transmissions in FM mode when out of range of the CC.

 

[INDY72]

If it is LTR Multinet then there would be a control chan of sorts... LTR Regular usually has data bursts every ten or so seconds on every active repeater, and LTR Passport has them every 2 or so seconds... Data bursts sound much like a key up with NO modulation. If its an Passport system, there curently is NO scanner that can trunk track this system, but you can monitor conventionally with NO delay on the freqs.... The only way to trunk track LTR Multinet is with a PC using LTRDump/LTRTrunk. Regular LTR can be trunk tracked on any of the trunkers featuring LTR...

PRO-92/2067's... PRO-97, PRO-2051, PRO-2055

Most of the newer Uniden Trunkers do LTR.

There is current research into Passport LTR capable scanners,... But I would not expect one on the market for at least another year....

 

[fuctea2k]

Thank you

Thank you for the info!

I also find that the system has data bursts every ten or so seconds on it's active repeaters, 856.1875, 857.1875, 858.1875, 859.1875, 860.1875, 856.8875, 857.8875, 858.8875, 859.8875, 860.8875. and I NEVER hear talkgroup call and simplex call, they only make duplex phone calls, and very different from motorola systems, when they making phone calls, I can't hear they dial numbers, I mean I can't hear the dialing DTMF tone, what I hear is the phone without dial and directly get Connected Tone and wait somebody to answer it.
If someone "phone" the radio, there will be a ring tone on the active repeaters.

I'm sorry for my English.



Thank you!

 

[WayneH]

My wager is on LTR.

You can have UNIT ID signalling at the end of transmissions which would create the beeps or whatever it sounds like. There are a few formats such Kenwood's FleetSync.

You can have the base station not retransmit the dialed number with LTR also.

-Wayne

 

[INDY72]

According to the im's we talked on last night.. his description is indeed an LTR standard utilizing a LOT of telephone interconnects for the Chinese National Railroad.

 

[JGP]

Someone posted a new TRS in the database. It is the SC Johnson Wax System in Sturtevant (Racine County), Wisconsin. Seven unconfirmed frequencies are listed, and it is claimed to be an LTR system.

My question is, how does one know for sure that it is LTR without even posting one LCN for the system?

If someone claims a system is LTR and posts it in the database, it should have some LCN's for the system.

Am I right or wrong to think this way? :?

Joel

 

[ericcarlson]

My question is, how does one know for sure that it is LTR without even posting one LCN for the system?

You're right; in general, it is a little sketchy. However, there are scanners that "track" LTR without having the channels in LCN order.

-Eric

 

[JGP]

Good point..., but maybe some people around Racine County can help me map this system with Uniden scanners.

This is a factory. It could be a low power system where you have to be close to pick it up.

Joel

 

[W4KRR]

If you have access to a Radio Shack PRO-92 or PRO-2067 scanner, you just program the frequency, set the mode for LTR and wait for a transmission. If a six digit talkgroup appears, it's part of an LTR system. The PRO-92 and PRO-2067 scanners will track LTR without the need to enter the frequencies in any particular order, they just don't do it as well as the Unidens.

 

[JGP]

Ken,

I have a BC780XLT. I have to get or find the LCN's the hard way for an LTR system, but this is all part of the fun of having a scanner.

Joel

 

[W4KRR]

Ken,

I have a BC780XLT. I have to get or find the LCN's the hard way for an LTR system, but this is all part of the fun of having a scanner.

Joel

Well you can have a whole pantload of fun with the PRO-92 and PRO-2067, as neither of them will tell you the correct LCN's for an LTR (or EDACS for that matter) system. :lol:

My post merely said that you can use the PRO-92 to tell if a transmission on a particular frequency was LTR or not. I don't think that there's any hardware or software out there that will tell you the correct LCN's for EDACS or LTR systems. Enjoy!

 

[JGP]

Ken,

I agree with your post, and thank you for the information.

Joel

 

[Tim]

Howdy All...

Don't forget, it's a good idea to leave Pro 92 (Or whatever scanner) on the frequency you suspect as LTR. For Unidens you have to have the bank set to LTR Mode and then hold down on that frequency. A lot of times the CWID broadcasts the LCN for that frequency. Like Marquette University's LTR system here in Milwaukee (WI).

(02) 461.9875
(06) 462.1625
(14) 464.6875

All of them broadcast a morse code CWID like every 15 minutes or so and it will show 0-02-253 (..on 461.9875), 0-06-253 (..on 462.1625), etc. The "253" is the CWID and the "02" is the LCN order.

Tim
Milwaukee, WI

 

[Halfpint]

Howdy All...

Don't forget, it's a good idea to leave Pro 92 (Or whatever scanner) on the frequency you suspect as LTR. For Unidens you have to have the bank set to LTR Mode and then hold down on that frequency. A lot of times the CWID broadcasts the LCN for that frequency. Like Marquette University's LTR system here in Milwaukee (WI).

(02) 461.9875
(06) 462.1625
(14) 464.6875

All of them broadcast a morse code CWID like every 15 minutes or so and it will show 0-02-253 (..on 461.9875), 0-06-253 (..on 462.1625), etc. The "253" is the CWID and the "02" is the LCN order.

Tim
Milwaukee, WI

Don't forget to set the `channel' to LTR along with setting the `bank' to LTR on the 92/2067s or the 97. {GRIN!}

 

[INDY72]

Correct... You can find the LCN's on a smaller system easily with a 92....

 

[pro92b]

You can find the LCN's on a smaller system easily with a 92

How do you do that?

 

[JGP]

w4krr, kEN, SAID IN HIS POST: "...WITH THE PRO-92 AND THE PRO-2067, AS NEITHER OF THEM WILL TELL YOU THE CORRECT LCN'S FOR AN LTR (OR EDACS FOR THAT MATTER) SYSTEM."

milf, your post is in conflict with Ken's. Do you mean LCN or freqquency? I am asking because I don't know what R/S products can do. I don't mean to be a smart a... because I am the last one to claim I know it all. I own Uniden scanners.

Joel