Question about patch with LTAC-1

jdm911 · #1 (**permalink**) 10-28-2009, 10:31 PM

I am asking this because I thought I understood how patches worked, now I am not sure. Earlier tonight TG: 4304 showed up here in Duluth. Using the database and the MN Wiki I was able to figure out that this was Dakota County (West St. Paul officers). When the patch was taken off the dispatcher mentioned taking off the patch with LTAC-1. My question is, I thought that TG: 504 would be the talkgroup shown if something was patched to LTAC-1. I was doing ID Search and have LTAC-1 programmed in but at no time did LTAC-1 ID:504 receive (and the display only showed ID: 4304). I am missing something or is this how it usually works? ARMER is very new in these parts and this is one of the first patches that I have heard. Also...if it matters, I was using 396xt in display mode 2. Thanks to all.

wogggieee · #2 (**permalink**) 10-29-2009, 12:21 AM

It is likely that there was someone up there monitoring TG: 4304 which would make it active up there. At the same time there was likely an incident in the Dakota County area that was involving outside agencies, like the state patrol, so they were using LTAC-1 so the SP can communicate with Dakota County. However since there was no one in your area that was monitoring LTAC that talkgroup is not simulcast up there. Does that make sense?

stmills · #3 (**permalink**) 10-29-2009, 02:16 AM

From what I have been able to monitor with patchs on the Metro armer it seems that the 2 tgs get tied together and voice traffic only is carried on one. Example Ramsey County Usually has West and Central Dispatch tgs patched together and traffic is only heard on one of the tgs. Say TG A is Patched to TG B traffic from radios on TG B is directed to TG A, but if TG B is Patched to TG A traffic from radios on TG A is directed to TG B.

Steve

jdm911 · #4 (**permalink**) 10-29-2009, 08:24 AM

Thanks to both of you. Each of your replies make sense. I see (on Pro96Com decoding software) that at approx 1 am this morning there was another patch to LTAC-1 (patched very briefly with 54-msp w). My other thought in all of this is that, as presumably more equipment and radios get installed in this area, more of the interoperability capabilities will be heard. Thanks again.

and wogggieee you are correct, I did hear msp helicopter during that patch on 4304. Thanks

Raven95150 · #5 (**permalink**) 10-29-2009, 03:59 PM

Quote:

Originally Posted by stmills

From what I have been able to monitor with patchs on the Metro armer it seems that the 2 tgs get tied together and voice traffic only is carried on one. Example Ramsey County Usually has West and Central Dispatch tgs patched together and traffic is only heard on one of the tgs. Say TG A is Patched to TG B traffic from radios on TG B is directed to TG A, but if TG B is Patched to TG A traffic from radios on TG A is directed to TG B.

Steve

I think this is because a scanner won't properly track patched TGs.

I've noticed that sometimes when I hit hold on a TG that has been patched, I will suddenly stop hearing the traffic. If I hit scan, I will then hear the traffic on the other TG that was patched.

If you were actually using a radio that's affiliated on the system, you would hear all the traffic on every TG that was patched.

stmills · #6 (**permalink**) 10-29-2009, 04:09 PM

If you look at a datafeed of control channel data - unitrunker etc- when a patch takes place only one talkgroup shows up on an rf channel. I believe the system is redirecting the radios to the patched tg using only 1 rf channel for the patch, not sending rf on both tgs. So a system radio on TG A will remain on TG A on the radio but the RF is taking place on TG B that the patch is on- so a system radio could be on TG A or TG B but only 1 rf channel is taking place .

Steve

jdm911 · #7 (**permalink**) 10-29-2009, 05:37 PM

My concern then is this: If I sit on LTAC-1 thinking that I am going to hear anything that is patched to it I may in fact be missing some traffic. I will just have to wait until the circumstance presents itself again, maybe I will have to purchase another scanner in order to be sure, will have to explain this to my better half to justify. Thanks again all.

mmtstc · #8 (**permalink**) 11-02-2009, 07:58 AM

your advantage being up in duluth is that your volume of total traffic is far less than what is going on down here so skipping around isnt too much of an issue... but there isnt any shame in earnign yourself a second radio...