LTR Talkaround

KE7JFF · #1 (**permalink**) 01-13-2009, 01:10 AM

A friend of mine who uses an LTR system on their job. While I was getting his talkaround frequency, I found out that the talkaround frequency also emits LTR trunking data. I'm now kind of a puzzled as I thought talkaround was simply just an conventional frequency. A google search on the subject shows there's a difference between talkaround and simplex, but it does not explain the difference.

Any of the wise LTR gurus care to explain please?

NeFire242 · #2 (**permalink**) 01-13-2009, 04:48 AM

Talk-Around is simplex.

Yet on an LTR system you can use the data on T/A much like a PL or DPL. Only radios programmed with the same data burst will be able to talk to each other. Much like two radios that need to have the same DPL in order to talk to each other.

Dak48 · #3 (**permalink**) 01-13-2009, 07:36 AM

Someone correct me if I am wrong, but I seem to recall reading that LTR systems are single channel systems only, thus able to share control/voice/data on the same channel in some form.

fineshot1 · #4 (**permalink**) 01-13-2009, 09:27 AM

Quote:

Originally Posted by Dak48

Someone correct me if I am wrong, but I seem to recall reading that LTR systems are single channel systems only, thus able to share control/voice/data on the same channel in some form.

Sorry but your wrong. LTR systems can be single or many repeaters. Each LTR repeater will have its own LTR controller and each individual LTR repeater controller will connect with the LTR system master controller. And it should be noted that a repeater runs on a PAIR or channels(input and output).

ke5fgc · #5 (**permalink**) 01-13-2009, 09:56 AM

On my kenwood TK-880 a talk group can be programmed for talk-around. When selected it uses the home repeater output frequency that is selected for that particular system. The radio puts out a data stream that will unsquelch any radio that is programmed to listen to that talkgroup.

-josh

Dak48 · #6 (**permalink**) 01-13-2009, 10:18 AM

Quote:

Originally Posted by fineshot1

Sorry but your wrong. LTR systems can be single or many repeaters. Each LTR repeater will have its own LTR controller and each individual LTR repeater controller will connect with the LTR system master controller. And it should be noted that a repeater runs on a PAIR or channels(input and output).

I stand corrected and I thank you for my learning experience. I reckon I misinterpeted what I read.

I know there is LTR in Lincoln, NE but I haven't taken the time to listen to it, since looking at the listings, there is nothing of interest for me there. I think the cab company is on an LTR system, but I had enough listening of the dispatchers when I drove a cab, that I don't need to hear it now. LOL

tbiggums · #7 (**permalink**) 01-13-2009, 10:49 AM

A while back, I remember playing with an LTR radio that transmitted LTR data in the talkaround mode (no repeater). I think it was a Maxon TP-4800... I don't think all LTR radios have this capability, though.

KE7JFF · #8 (**permalink**) 01-13-2009, 01:50 PM

Thanks guys!

The radio he uses is a TK-880 which was sending out a a talkgroup ID of 1-01-001 which my PRO-106 scanner was of course saying it should be on LCN home channel 01. That is what was throwing me off; but now I understand it uses the LTR data for squelch which is pretty clever. Also explains why he couldn't hear me when I tried talking to him on talkaround on my UHF radio (hey, he has the power to authorize me!)

NeFire242 · #9 (**permalink**) 01-14-2009, 01:55 AM

Yeah its a neat idea to use the LTR data much like PL. It makes it a lot better just for that reason, even if someone does have the right PL etc, they'd still need the data stream to talk to one another. Just an extra step in the process I guess for authorized users.

LTRs can be tricky too, I've seen some where only the home repeater will send the data bursts every few seconds and the others will remain silent and idol until the system requires them to be open. It makes mapping an LTR out a bit more work. Plus LTR can have some talkgroups or PLs that will turn the LTR controller into a conventional repeater in the event non-LTR users need to contact LTR users. There is a lot you can do with them, plus combine fleet sync and messaging. Lots of possibilities.

traumacop · #10 (**permalink**) 01-14-2009, 11:00 AM

Can Moto do that?

We just started using a local LTR system as a back up to our primary public safety repeater and I'm just starting to learn about LTR. Nice to know there is some kind of out if a handheld on the fireground can't hit the repeater system.

Thanks for the information

tbiggums · #11 (**permalink**) 01-14-2009, 11:44 AM

It's been a long time since I've used these LTR radios, but I had an old Motorola Mostar that did LTR on 800 MHz. It was a single channel unit, and didn't have any talkaround capability.

The Maxon TP-4800's would communicate with the Mostar just fine through the system repeaters, but I seem to remember that when the Maxon TP-4800's were put in talkaround mode, the Mostar wouldn't unmute for them (all radios were programmed to use the same area/group and home channel). So there may be some slight difference in the LTR data that the Maxon's send in talkaround mode, versus what the repeater sends. Of course that Mostar was a really old radio, so the modern Motorola LTR radios may do talkaround in LTR.

I am sure the Maxon's were transmitting LTR data in talkaround, and not standard PL or DPL.

I've still got the Maxon's, but the Mostar is long gone. Maybe when I get a chance, I'll test them out with one of the computer LTR decoding utilities.