Jail traffic on Phoenix Fire

[hulka]

I have the jails locked out on my MCSO favor list in my SDS 100 & 200. I did notice that I do pick up jail traffic on K deck channels. I have both systems programmed out of the database on here and did check to make sure that I did not change something by accident. Only thing I see in common is they have the same talkgroup. Anyone else notice this before I delete everything and start fresh.

I am in Laveen.

 

[KB7MIB]

Do you by chance have both systems programmed in the same favorites list? You can't have two separate systems programmed into the same FL. They must be in separate FL's.

John
Peoria

 

[rpgaun]

Sitting her now (1/25 @ 21:30hrs) copying strange traffic on K7 (TG1614) off of Sacaton Mountain. It also sounds like traffic you would hear on a Jail TG. This is the first time I have heard this, I haven't reprogrammed or changed the radio in anyway for at least a month.

 

[cellphone]

I think rpgaun's post about receiving it off Sacaton site is a good clue.

There are two systems that come into play:

Regional Wireless Cooperative (RWC) Trunking System, Phoenix, Arizona

Regional Wireless Cooperative (RWC) Trunking System Profile

www.radioreference.com

Talkgroup 1614 Phoenix Fire K7 - FDCOM 7 - East

Maricopa County Trunking System, Maricopa County, Arizona

Maricopa County Trunking System Profile

www.radioreference.com

Talkgroup 1614 Detention Durango Jail Main Ops

There are some shared frequencies between the systems, and you are likely receiving the Maricopa County system even though you have it programmed for RWC. 772.96875 is a control channel for the RWC Sacaton site. 772.96875 is also a control channel for the Maricopa County P25 Phoenix Simulcast. There are also some other overlaps like 773.96875 which is a voice channel for RWC Sacaton Site and a control channel for the Maricopa P25 White Tanks site. There are also overlaps in other talkgroup numbers between the two systems (i.e. 1615, 1620, 1625, 1626, 1628, etc).

If you have the RWC Sacaton site programmed, your radio is probably actually receiving the Maricopa P25 system. Hulka mentions that you are in Laveen, and rpgaun's profile mentions that you are in Sun City. From either of these locations, you are likely not really receiving the RWC Sacaton site. I think South Mountain would be in your way and block the signal. The easiest way to solve the issue would be to avoid the Sacaton site as you likely cannot receive it anyway. In hulka's case, it might be another site. I did not go through all the frequencies matches between the two systems.

I am familiar with the BCD536HP and SDS100/200 and there are a couple ways to tell next time you see this occur. On both radios, there is a digital status if you have the display in detailed mode. If you see a talkgroup 1614 with a PT0 or PT1, this is receiving a P25 Phase 2 talkgroup and you are receiving the Marciopa County System. If you see talkgroup 1614 with "P25" this is a P25 Phase 1 talkgroup and you are receiving the RWC. On the SDS100/200 detailed display mode, you can also add the System, RFSS and Site ID to tell exactly what site you are receving.

I hope this all makes some sense.

 

[Jay911]

I am familiar with the BCD536HP and SDS100/200 and there are a couple ways to tell next time you see this occur. On both radios, there is a digital status if you have the display in detailed mode. If you see a talkgroup 1614 with a PT0 or PT1, this is receiving a P25 Phase 2 talkgroup and you are receiving the Marciopa County System. If you see talkgroup 1614 with "P25" this is a P25 Phase 1 talkgroup and you are receiving the RWC. On the SDS100/200 detailed display mode, you can also add the System, RFSS and Site ID to tell exactly what site you are receving.

An important option to try with an SDS radio is the Site NAC feature in a Favorites List (System>Site>Options>P25 NAC). I wish they'd add this feature to the x36 line as well. Every site in a system will broadcast a NAC unique to itself and it will not be (or should not be) the same as the NAC for another system's site(s). If you know the Site NAC value (another item that the SDS's detailed display mode can show), entering it in this field (and enabling its use - I forget if there's a setting for that or not in the overall options, probably is) will ensure that you are only getting traffic that is for the actual site your scanner thinks it's on.

 

[cellphone]

Great suggestion about using Site NAC Jay! Site NACs for both of these systems are documented in the DB under each of the individual sites.

 

[rpgaun]

Thanks guys for all the input. I'm using a 325P2 with a Optoelectronics BB-85 antenna. So, I'm probably not receiving the Sacaton site here in Sun City. I have it in the radio for our monthly trips to Tucson. In my mind it's strange that two systems, in the same geographic area would use the same frequency as a control channel. Guess frequency coordination or even techs talking to each other is a thing of the past.

 

[KB7MIB]

Given the distance between the White Tanks, and Sacaton Peak, with South Mtn in between, they probably didn't figure there'd be an issue. And there probably isn't unless you're running a base antenna with some elevation.

On the SDS scanners, you can do a site avoid. I'd suggest doing so, so as to eliminate the "false" reception issues. (Also, the more sites the scanner is checking, the longer it takes to move to the next favorites list. Enable the site avoid on every site not within the immediate area, to speed up your scan speed.)

Sacaton Mtns

Interactive Mapper - ScienceBase-Catalog

www.sciencebase.gov

John
Peoria

 

[hulka]

Sorry for the delayed response.
I have the RWC in one list and Maricopa in another.

I will pay attention to it next time I see it pop up on the display for the pt1 or 2.

i did see the overlapping talk groups as how I came about this. I was getting jail come on some of the FD events talk groups. I did not think about same frequencies though.