LA County CWIRS P25 Upgrade - On the air

[LAflyer]

Thanks for that, but I am really confused now.

Some of these frequencies are identical to Site 20, which we said was the East simulcast with sites on Johnstone, Puente Hills, Whittier, Puddingstone based on FCC licences.

More specifically 851.9625 and 853.5875 were noted as the CC for Site 20, while 852.5875 was an Alt.

Looking at FCC licences - 851.9625, 852.5875, 852.9625, 853.3000, 853.5875 are all licences in East part of the county, while there is no license for 853.9125. Could that one be a typo?

Is there anyone East that can see if they receive Site-20 - East Simulcast still?

Also a bit unusual for you to receive that far East from SCV ha?

 

[bcorbin]

Checked, double-checked and more... No typo...

Signal's not great, but I can decode it on all the gear...

 

[WayneH]

I *am* using the PC outputs on both radios... which means I'm relying on GRE's DSP to do the churning - the -800's DSP is evidently more tolerant of whatever is happening than the -600's.

I think you missed what I meant. The PC/IF connection will spit out the data packets so 600 or 800 it's going to send the same OSPs out that port if it's a 9600 CC. There are times where programs like PRO96COM do not have identifying packets that will allow it to decode the system.

I would argue that P2 is a bit more than a voice thing

TDMA is only used on a 9600 trunked system for voice channels. Whether the system is TDMA, FDMA or DDM how the control channel comes to be is the same regardless of voice modulation. I know this because I work on M 9600 systems on a daily basis. I don't want to go OT anymore so if you want to pursue this then email me.

 

[bcorbin]

Please, don't anyone mistake me for someone who knows what they're doing 8*) But that's why I threw my observations out there and asked...

If I tune to a CC that is decoding like it should, there is a periodicity in the audible stream and the transitions sound nice and crisp. That's not what I'm hearing on 851.2125...

I would say it sounds a lot like white noise, but it's a bit more like listening to data streaming in a wide bandwidth. You can hear something like that same periodicity you hear in the functioning stream, but there's nothing crisp about it, and in fact, you kind of have to dig in to hear it... (not unlike listening to AM on an FM receiver, except that it's nothing like...). Not terribly unlike what you might hear on a Fleet Broadcast downlink if you listen on a consumer-grade scanner.

Given that a) it seems a little strange to leave a system up and transmitting for any length of time in such a useless state (I'll forget for a moment about that NOAA transmitter that's been broadcasting noise for weeks), b) this was a pattern I'd seen during the burn-in of another P-II system on another band and c) I was able to decode for a time on a receiver with a more diverse demodulator/DSP, it seemed prudent to try to eliminate the possibility that there might be additional ways to modulate the CC stream during testing phase. Not to say that that possibility made any more sense in the grand scheme of things.

What I seem to be learning here is that it's pretty darn hard to get the CC up and running in a stable, usable mode on a Harris system (two out of the three burn-in's I've encountered have floundered like this)...

Thanks and regards...

I think you missed what I meant. The PC/IF connection will spit out the data packets so 600 or 800 it's going to send the same OSPs out that port if it's a 9600 CC. There are times where programs like PRO96COM do not have identifying packets that will allow it to decode the system.

TDMA is only used on a 9600 trunked system for voice channels. Whether the system is TDMA, FDMA or DDM how the control channel comes to be is the same regardless of voice modulation. I know this because I work on M 9600 systems on a daily basis. I don't want to go OT anymore so if you want to pursue this then email me.

 

[LAflyer]

OK site 39 added to Db.
For future need to confirm sites location and also clarify duplicate frequencies with Site 20.

 

[scannerbuff999]

can i use my bcd396xt on this system

 

[bravo14]

can i use my bcd396xt on this system

I Don't think so. Since the system is a Phase ll.

 

[scannerbuff999]

ok thanks that what i thought i will use the 436
thanks for the help

 

[bcorbin]

OK site 39 added to Db.
For future need to confirm sites location and also clarify duplicate frequencies with Site 20.

I will keep an eye on things periodically, and report back 8*)

(Site 30 still sounds like junk)

 

[LAflyer]

Today picking up Site - 10 (T0A0A)

851.0875
851.2500
851.4375
851.7750
851.8000
852.2250
852.7500
853.0875CC
853.4375
853.7250

NAC 00A

I presume this might be the Basin Simulcast with 10 channels which was to have sites on Verdugo Peak, Lukens, Oat and Downtown LA.
A little hard to confirm as I cant find a valid FCC license held by LACo for any of the above frequencies (yet).

 

[bcorbin]

I can barely hear the CC for site 10 in the SCV and up at the northern end of the 405, so I think we can rule Oat out, for now.

The CC has been tweaked back into shape on Site 30, and they're running test-tones ( $293/TGID=1 ) and test counts ($00A) on 852.3125 and 853.8375 (the alternate CC's for Site 30). Pro96Com is showing TG:64001 in use --- that would be the test-counts interrupting the test-tones.

Site 30 is not reporting any adjacent sites at this time.

 

[WayneH]

20-20 likely indicates site 20, RFSS 20. Not sure about 0105h. Existing site in the DB is 40-40.

With Harris systems the "RFSS" will echo the site number. Harris does things differently than Motorola in that the SysID is the Zone, and the WACN is seen as the "System ID" for security purposes when programming the radio. In the context of Motorola the RFSS is the Zone core number.

 

[scma127]

i programmed it in and i did not hear anything

 

[bcorbin]

Site 30 came back up from the dead some time around noon today. LOTS of testing on TG 64004 - with references made to being on the "Northwest System" and the "West" system. There were check-ins from Pyramid Lake, Torrance and Los Alamitos. Interestingly enough, Site 30 isn't reporting any adjacent sites (per Pro96Com). None of the system parameters have changed.

 

[inigo88]

Found "Antelope 2" on Lower Blue Ridge while driving past Wrightwood on Hwy 138 last night, and updated the db.

Frequency: 853.75 MHz
SysID: 105, WACN: 91FE5
RFSS/Site: 59-59
NAC: 00A
WQUT994 (LOS ANGELES, COUNTY OF) FCC Callsign Details

Along Hwy 138 I could hear control channels on Antelope 2 (59-59), Hauser (57-57) and NW Simulcast (30-30). I didn't catch any other control channels that would indicate Antelope 1 (Blue Rock) is on the air yet.

I also found a constant test tone on 851.7125 MHz, NAC 293, which I assume they're using for coverage analysis. It was very strong in Wrightwood but it looks like the only LA County licenses for it are up in the NW Simulcast area.

 

[LAflyer]

Thanks Indigo88.

Anyone close by able run a trunk tracker on 853.75 and determine the other site frequencies?

Also from more recent LACo document that zone is now called simply "Lower Blue Ridge", not Antelope 2 any longer.
While Antelope 1 is also now termed as "Blue Rock" zone.

 

[inigo88]

Thanks for correcting the database. When Blue Rock does show up, I suspect it'll be RFSS/Site 58-58.

 

[LAflyer]

Looks like another site is up..

Site 51
851.275a
852.0875a
852.775a
853.275a
853.800c

NAC 00A.

Not sure of its location, but could be Catalina(Blackjack) or even Castro standalone sites as submitter said they received the site from SouthBay.
If anyone closer could give a listen and try to confirm.

 

[LAflyer]

Just to summarize what we have so far in the Db.

Confirmed

Wide area Simulcast
Basin - Site ID 010
East - Site ID 020
Northwest - Site ID 030
West - Site ID 040

Stand alone sites
Hauser - Site ID 057
Lower Blue Ridge - Site ID 059

Pending

Stand alone sites
Castro
Black Jack
Blue Rock

 

[bcorbin]

Per some of the conversations last week, Blackjack should be up.

Looks like another site is up..

Site 51
851.275a
852.0875a
852.775a
853.275a
853.800c

NAC 00A.

Not sure of its location, but could be Catalina(Blackjack) or even Castro standalone sites as submitter said they received the site from SouthBay.
If anyone closer could give a listen and try to confirm.