scanning la county sheriff??

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scannerface27

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alright, ive been scanning laso for a while now, and know about the high 480 system they are on. What ive been doing to scan them is just put in the base, and mobile frequencies. Sometimes ill get the beep beep. and sometimes depending on where i am, ill get some feild traffic.. Which brings me to my question, as i was programming my 396xt, i read the little article on the database, before the frequencies, that explains this. see paragraph below...now does this mean if i put in the ltac frequencies i will here the feild units... or do i have to put in the input freqs, and what are they....????? here is the article I was talking about.. mainly Los Angeles County Sheriff's Department operates a conventional radio system referred to as the "480 System" within the department, because of the frequencies it occupies. The system uses over sixty repeater sites around the county, most of which are on hilltops, to relay communications. The hilltops from which a particular repeater transmits from is dependant upon the area that channel was intended to cover. Communications on a particular channel will sound the best when monitoring from within or near the area that the personnel assigned to that channel patrol.

With the exception of Special Units Dispatch (which has countywide coverage), Dispatch and Local Tactical channels each have the smallest area of intended coverage. As a result, a listener must be relatively closer to a particular dispatch area to hear communications on that channel clearly. Conversely, Area Tactical and Countywide Tactical channels each are intended to cover the territory of several or all of the dispatch channels combined. As a result, listeners can hear communications on any given Area Tactical and Countywide Tactical channels from further reaches of the county than corresponding Local Tactical or Dispatch channels. While these repeater configurations provide varying degrees of expanded coverage on a particular channel, personnel may bypass the repeaters and use simplex on any channel, commonly referred to as "direct", "talk-around", or "car to car" operation.

The Sheriff's Communications Center (SCC) is located in East Los Angeles near the Biscaluze Jail, and dispatchers all incidents countywide. To assist SCC in confirming who is transmitting, each time a deputy presses the transmit button on his radio the radio transmits a unique identifier (called a "G-Star AID", "burp", or "burst" encoder, or more commonly a "turkey call"). The unique IDs are displayed on the SCC dispatcher's screen. When a radio's emergency trigger (also called "E-Trigger" or man down switch.) is activated, the radio switches to the emergency channel and transmits the Radio ID five times.

Each sheriff's station has a Dispatch channel and a Local Tactical ('L-TAC') channel, each of which may be permanently shared with one or more other stations depending on the volume of station radio activity. Nearly all incidents and communications begin on a Dispatch channel (and then could switch to L-TAC / A-TAC / C-TAC or STAR-TAC). This last pargraph is what i am inquiring about.. NOTE: Mobile traffic is not rebroadcasted over the output frequency of the dispatch channels. Instead, only a beeping tone is broadcast to signify to the field units that someone is talking. To monitor units in the field you must program in the input frequencies also. The corresponding L-TAC channel is included in brackets.
 

jrholm

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Okay I'm having a hard timefiguring out your question here, but I'll try my best.

The dispatch channels have a busy tone when units in the field are talking. All you will hear is the dispatcher (PSD) unless you have the input freq. and are close enough to hear those units in the field. The L-Tac channel has no busy tone and you will hear both sides of the conversation.
 

2wayfreq

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The input freqs are 3 MHz higher than the output. So Let's say DISP-14 483.1375 RX. The TX is 486.1375. So, you would also program the input freq as well, I would find a way have the input freq situated so you can immediately scan for the reply. Its interesting to hear that side of the conversation at times.
 

scannerface27

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ok ythanks guys i get it i beleive the mobiles are 3 steps higher in mhz... the last paragraph was where my question was sorry for the long post/ here it is.... NOTE: Mobile traffic is not rebroadcasted over the output frequency of the dispatch channels. Instead, only a beeping tone is broadcast to signify to the field units that someone is talking. To monitor units in the field you must program in the input frequencies also. The corresponding L-TAC channel is included in brackets.
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Uplink

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ok ythanks guys i get it i beleive the mobiles are 3 steps higher in mhz... the last paragraph was where my question was sorry for the long post/ here it is.... NOTE: Mobile traffic is not rebroadcasted over the output frequency of the dispatch channels. Instead, only a beeping tone is broadcast to signify to the field units that someone is talking. To monitor units in the field you must program in the input frequencies also. The corresponding L-TAC channel is included in brackets.
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I wasn't sure what your question was either reading this. (there must be a question mark filter on here somewhere :D

You don't need the input freq for the L-TACs, as they are normal repeaters.

Yes, +3mHz is correct for that part of the band.

Try this for the LASD DISPATCH freqs: Program the INPUT freq on the channel BEFORE the OUTPUT freq. Put the DELAY ON for the INPUT freq and the DELAY OFF on the OUTPUT freqs, you'll catch the mobiles more this way and have less annoying beeping.

Hope that helps?
 
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inigo88

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The L-TAC being in brackets is referring to the "Description" field of each dispatch channel. It has nothing to do with the mobiles being repeated on the output frequency (you can tell by reading the type field - L-TAC says "RM" for Repeater Mobile and Dispatch says "BM" for Base Mobile).

Since the L-TAC channel numbers do not coorespond to the Dispatch channel numbers, and since the L-TACs are used secondary to the dispatch channels (and when scanner-worthy things are going on in that area), wouldn't it be handy to see the name of the cooresponding L-TAC channel when looking at the dispatch channel? :)
 

jrholm

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If you want to hear the car to car traffic you will want to listen to the L-tac's. Most of the call coordination and stuff like that will be there, unless it's emergent in nature, then they will ask for "the patch" and the cars will be able to talk to each other on the dispatch channel and you will be able to hear them.
 

jrholm

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Also this evening LASD was on "self dispatch". During that time their CAD system is down and the stations are dispatching directly to their individual units by voice (all calls). Very old school with S.C.C. taken out of the loop. Good oportunity to listen to all the units without any busy tone.
 

scannerface27

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thanks for youre help everyone.. wow what a difference scanning lasd, when you have more channels put in rather then just base,and mobile...
 

ChrisW6YBW

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LASD monitoring tip

Since the LASD channel numbers for the dispatch channels do not exactly match the channel numbers for the LTAC, ATAC, and CTAC channels try this trick to make it easier to navigate your LASD channels during an incident. This is also the same plan that the LASD radios are programmed with to make it easier for the deputies to switch between their dispatch and their pre-designated tactical channels.

Dispatch channel - with 5 second hold
The LTAC channel associated with that station - lock out
The ATAC channel associated with that station - lock out
The CTAC channel associated with that station - lock out

You will end up with duplicate LTAC, ATAC, and CTAC's channels (not a problem with newer scanners with 5,000+ channels) but this makes it so much easier to move around the channels when you hear something interesting. You can find the LTAC, ATAC, and CTAC assignments on Radio Reference. Each station will always use their assigned LTAC and has a preferred choice for ATAC and CTAC. However, the choice of ATAC and CTAC may vary depending on if another station was already using it, but at least it is a start.

Another listener suggested programming the input channels along with each dispatch channel. Yes, this works but you need to be very close in order to hear the units on the input channel, especially if they are using their portable radio. You are really not missing much if you don't listen to the input side because a.) SCC dispatchers repeat what the units say, b.) they use LTAC for everything else worth listening to, and c.) if it is a hot incident they will be on the patch and you will hear everything. The only thing you will miss by not listening to the input side during an emergency is the initial "10-33," "998," or etc.

I hope this tip helps - happy listening!
 

ChrisW6YBW

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Also this evening LASD was on "self dispatch". During that time their CAD system is down and the stations are dispatching directly to their individual units by voice (all calls). Very old school with S.C.C. taken out of the loop. Good oportunity to listen to all the units without any busy tone.

And extremely entertaining sometimes too!!
 

jrholm

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I hope you weren't listening to A-tac-2. I was dispatcher that night and had some interesting comments for my field units. :D
 

petekob

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Proximity Question

Just joined here...I am releativly new to scanning about Southern California but have learned a lot in the past few weeks I have been playing around with a PRO-106 I got from Radio Shack. I got the mobile unit since I work on the road and it keeps me entertained along with helping with freeway traffic from CHP dispatch. The question I have regarding the LASD is about the +3mhz for the mobile units. Do you have to be in nearby proximity to the field units to hear that half of the conversation? What about channel conflicts when more then one unit is attempting to contact dispatch on the same frequency? Do you still get the beeping sound as with dispatch. I have been getting dispatch fine including all Tactical channels.Thanks.
 

scottbailey

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The question I have regarding the LASD is about the +3mhz for the mobile units. Do you have to be in nearby proximity to the field units to hear that half of the conversation? What about channel conflicts when more then one unit is attempting to contact dispatch on the same frequency? Do you still get the beeping sound as with dispatch. I have been getting dispatch fine including all Tactical channels.Thanks.

The LASD system works the same as any other repeater - except that instead of hearing the mobile units on the repeater output, you hear beeping instead. If you were to listen to the repeater input (+3 MHz) - and you were close enough to the unit transmitting, you would hear the actual deputy's transmission. You would never hear any beeps on the input channel.

By close enough, figure a ballpark of a mile or so if a handheld and a few miles if it's a mobile unit transmitting. If either you or the mobile unit gets some elevation, you can be further away - i.e. you'll be able to hear the helos from across the county. Get obstructions in between (even trees) and decrease that distance.
 

PaulNDaOC

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My experience over many years at SCC was most patrol deputies kept their mobile radio on their L-TAC most of the time and their portable on Dispatch in order to be able to monitor both at the same time..

This being the case you're going to have to be pretty close most of the times to catch the imput to SCC.

.
 
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6 years later and i can confirm this is still true knowledge about LA sheriff's codes. and OP's post really helped me understand even more how LA dispatching works. great post
 
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