Offset Talkgroup ID's for Emergency Traffic?

[Gamefreak88]

I've heard that talkgroup ID's are in increments of 16 and that if you add 1, 2, 3, etc to the "main" talkgroup ID, it is for different things, such as when they go to "ET" (Emergency Traffic) or when they are patching in with another talkgroup. Is this true?

The reason I ask, is because it would be fascinating to program all law enforcement talkgroup ID's (adjusted by +2 or whatever) and the scanner would ONLY open the squelch if they were on ET. I could drastically reduce the amount of chatter on my radios to only important radio traffic.

Example:1456 would become 1458.

Am I understanding this correctly?

ID+0 Normal Talkgroup
ID+1 All Talkgroup
ID+2 Emergency
ID+3 Talkgroup patch to another
ID+4 Emergency Patch
ID+5 Emergency multi-group
ID+6 Not assigned
ID+7 Multi-select (initiated by dispatcher)
ID+8 DES Encryption talkgroup
ID+9 DES All Talkgroup
ID+10 DES Emergency
ID+11 DES Talkgroup patch
ID+12 DES Emergency Patch
ID+13 DES Emergency multi-group
ID+14 Not assigned
ID+15 Multi-select DES TG

http://wiki.radioreference.com/index.php/Motorola_Type_II_SmartNet
Motorola Type II - The RadioReference Wiki

 

[exkalibur]

Totally possible. Set the scanner to detect the status bit and just add 2 to every decimal ID. I have a system on my 396 setup to do exactly this, with a custom alert tone enabled. Works pretty good!

 

[Gamefreak88]

I did some more research and it appears that although the Uniden 396 can handle status bits, the Radio Shack Pro-106/197 (aka GRECOM PSR500/PSR600) do not.

I did some testing by using two Pro-106's, listening to the same scanlist for "El Cajon PD", but with 1 I added a new talkgroup with the talkgroup ID +2 and then tried +4. Both radios keyed up the exact same, with one being "El Cajon Disp 1" and the altered one being "El Cajon Testing" which had priority enabled over the normal "El Cajon Disp 1". Point being (sorry if I didn't explain it too well), the Pro-106 considers any number higher than the "normal" number to be just the same.

So talkgroup ID 1456, 1458, 1460 etc would all pickup the exact same radio traffic.

Anyone else with the Radio Shack/GRECOM scanners tried this? I'm in San Diego, it may also be that my area is not Motorola Smart Zone II.

 

[W6KRU]

The county and the city of San Diego are both Moto Type II Smartzone systems.

 

[RKG]

Note that the status bit byte only applies to SmartNet/SmartZone (3600 baud) trunking. The status function is handled otherwise for Astro25 (9600 baud) trunking.

 

[Gamefreak88]

Thanks for the clarification DDan, I wasn't sure which version SD was.

I'll admit I'm a little confused by the lingo you guys are using. In essence, San Diego City and County are both "compatible" with what I'm looking to do, but my scanner isn't? So if I got a Uniden, I should be able to do what I'm looking to do correct? Are there any exceptions or is it just system-wide it'll work for all talkgroups?

 

[JoeyC]

I don't believe that you will hear much of anything if trying to listen to the +2 status bit for ET.
I am not sure about this, and really haven't run any tests, but I believe for these status bit options to function requires certain situations to occur. For instance, I believe you are not going to hear (for instance) SDPD Western emergency traffic on 1618 when they call ET on the channel. For 1618 to function I believe someone in the field must throw the emergency button on their radio or the dispatcher must set up a mode that they don't appear to use. Just since reading this thread, I've done some tests on one of my Unidens. During ET on SDPD western a few ago, there was nothing over 1618. Also, when SDPD simulcasts across all division talkgroups, I don't believe they do a real MultiSelect (status bit +7) because shouldn't entering this mode only tie up one frequency in the trunk system? I've noticed when "simulcasting" for instance during BOLS, etc, if 7 talkgroups are selected, 7 frequencies are carrying the same traffic the way SDPD does it. (I am still waiting for a simulcast across talkgroups to occur to see if something comes up on one of the division TGs+7) I wouldn't think this is efficient use of trunking. But then again, I am not too sure exactly under what circumstances the status bit IDs function.

 

[exkalibur]

If the system is set to announce emergencies, the status bit will always go +2. Some systems (such as the one that is used provincially up here), the group won't announce the +2 to users.

 

[Gamefreak88]

Hey JoeyC (you've answered many of my questions before, thanks!)..

I tend to listen to certain talkgroups, such as El Cajon PD and Sheriff, but I only listen to Chula Vista PD, National City PD, Coronado PD, Harbor Patrol, etc if I am alerted via Law CC Interop or other means. Reason being is I can't follow the entire county and city.. too much chatter and I miss too much in my primary "beat" area of East County.

However, what I'd LOVE to do, is listen to my favorites (El Cajon/Sheriff/etc) under normal conditions, but also have things such as Chula Vista Dispatch 1 set to only pick up if it meets the Emergency status and have priority enabled. It would increase the chances of me hearing critical emergency radio traffic on talkgroups that I rarely listen to. And in the event I do hear the +2 talkgroup come on, I'd tune in to the "normal" +0 talkgroup from that point on in case they went off Emergency status.

Background info: I chase news overnight, so I must know everything thats going on as soon as possible.

 

[JoeyC]

Gamefreak. I think your best bet is to monitor Law CC and Law Air for the intel about hot radio traffic and where to switch if necessary, but I totally understand your logic in this. There is just TOO much going on in this county!

 

[JoeyC]

One thing I do with SDPD is I have what the dispatchers refer to as "the desk" (911 call takers) radio IDs tagged to have an alert tone when they are transmitting. This gives me a heads up (through all the chatter) that something hot may be going down shortly since it is these calls that usually end up being those with the most listening value to me. I do this with ABLE and ASTREA as well.

 

[Gamefreak88]

By radio ID's, do you mean you can essentially say "I want to listen to Officer Smith" and only his mic-presses will be heard? Could you elaborate more on how you have yours planned out? I'm confused (and intrigued) by how listening to certain officers/dispatchers is beneificial.. isn't that like listening to a trunking frequency with an analog radio (you hear dozens of different conversations since they bounce from freq to freq). You'd only hear, for example, the Western dispatcher speaking but not the officer.

As for listening to Law CC, Law Air, Fire CC, Fire Air, etc.. thats what I do now and it works, but in my line of work an extra 30 seconds CAN make a $500 difference on a single call. When I hear something (e.g. El Cajon Disp 1), I start rolling to it within seconds. Often 20 seconds, even minutes, elapse before units request a K9, ASTREA, ABLE, put out a BOL, etc. That is critical time where shots are being fired, victims are being rescued, etc.. and I must get that on tape.

 

[JoeyC]

It doesnt work like that. You cannot limit which radioIDs you hear but you can tag them to show an alphatag, or to have an alert of some sort (depending on radio of course). I use the alert tone tagged IDs to stand out among the radio chatter. So it brings my attention to the radio when these certain tagged radios transmit.

 

[box23]

It doesnt work like that. You cannot limit which radioIDs you hear but you can tag them to show an alphatag, or to have an alert of some sort (depending on radio of course). I use the alert tone tagged IDs to stand out among the radio chatter. So it brings my attention to the radio when these certain tagged radios transmit.

What radio are you using? One of the Unidens?

 

[JoeyC]

What radio are you using? One of the Unidens?

The radios I have that do RadioID tagging are the 996XT and 2 GREs (PSR500 & 800).

 

[box23]

The radios I have that do RadioID tagging are the 996XT and 2 GREs (PSR500 & 800).

OK. And your using the 996XT to alert on a radio ID? I thought only a name could be applied to a radio ID, not an alert.

 

[JoeyC]

OK. And your using the 996XT to alert on a radio ID? I thought only a name could be applied to a radio ID, not an alert.

Quite possibly true. The 996XT lives installed in the car and I can't say that I actually have heard one of my tagged IDs there, but I also don't listen to it nearly as often as I do my other Unidens (that don't do RadioIDs) and the GREs. Sorry for any misinformation given.

 

[box23]

Quite possibly true. The 996XT lives installed in the car and I can't say that I actually have heard one of my tagged IDs there, but I also don't listen to it nearly as often as I do my other Unidens (that don't do RadioIDs) and the GREs. Sorry for any misinformation given.

OK, that makes sense. I was just hoping it magically started working like that.