Talk:Logic Trunked Radio (LTR)

I just tried using ltr analyzer on the samples provided on the main page , and it didn't decode anything ,
Normally when you listen to ltr audio it you will notice a low rumbling sound in the background which is the data being transmitted

you will also notice little " chirps or blips " about every 10 sec when that channel / frequency is not in use.

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I'll try to grab a sample of audio when i can , but right now my antenna is shot and my quality of signals is limited --Mbeam (talk) 20:16, 5 August 2016 (NZST)

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== Audio Sample ==

decoded is:

- OSW: 0 05 05 004 03 3D   Area=0  COMM  ID=5-4 on Ch05  FREE=3   LCN=5
- OSW: 0 05 05 004 01 3A  COMM  ID=5-4 on Ch05  FREE=1   LCN=5
- OSW: 0 05 05 004 02 7E  COMM  ID=5-4 on Ch05  FREE=2   LCN=5
- OSW: 0 05 05 004 03 3D  COMM  ID=5-4 on Ch05  FREE=3   LCN=5
- OSW: 0 05 05 004 01 3A  COMM  ID=5-4 on Ch05  FREE=1   LCN=5
- OSW: 0 05 05 004 02 7E  COMM  ID=5-4 on Ch05  FREE=2   LCN=5
- OSW: 0 05 05 004 03 3D  COMM  ID=5-4 on Ch05  FREE=3   LCN=5
- OSW: 0 31 05 004 05 06  END   ID=5-4  LCN=5
- OSW: 0 31 05 004 05 06  END   ID=5-4  LCN=5
- OSW: 0 31 05 004 05 06  END   ID=5-4  LCN=5

If you wish you can replace / convert this talk page into LTR Page and re-label / move the data on the main page --Mbeam (talk) 21:17, 5 August 2016 (NZST)

Good analysis Mbeam, I'll take a look into this later, and I definitely support moving this current page to UNID. --Cartoonman (talk) 13:36, 7 August 2016 (NZST)

Yes, LTR is not easily heard, as it is usually heard in a cw type modulation-audio wise..

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Finally got around to move this into the real page. Someone can make it more informational later. --Cartoonman (talk) 04:08, 10 February 2017 (NZDT)

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Um, there are a ton of ltrs around my area, it is still active...most of them just don't have voices, just mics being keyed on and off...ywsia1

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According to RadioReference.com, "Typically on LTR systems, each of these controllers periodically sends out a data burst (approximately every 10 seconds on LTR Standard systems) so that the subscriber units know that the system is there. Some systems will broadcast idle data bursts only on channels used as home channels and not on those used for "overflow" conversations. To a scanner user the idle data burst will sound like a short blip of static like someone keyed up and unkeyed a radio within about 1/2 second"

So I believe those mics being keys on and off might be the LTR idle data, because LTR is apparently transmitted along the FMFrequency Modulation carrier as a sub-audible data, kinda like CTCSS.--Cartoonman (talk) 13:09, 10 February 2017 (NZDT)

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Uploaded a temp screenshot to show what the chirps look like .. will create a better one later
The Yellow circles are around the little blip idle data chirps

The 2 red circles are 2 different ltr conversations taking place

Ltr Chirp af and iq with txt file with decoded data https://drive.google.com/open?id=0B-Cy0hRpwjmwUWZ5dFh2d204cVU --Mbeam (talk) 21:40, 10 February 2017 (NZDT)