Los Angeles County California

See the LA County Wiki under "Collaborate" for unit IDs and more information.

The following explanation is an excerpt directly from the Southern California Frequency Directory:

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).

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.

Local Tactical ('L-TAC') channels are used by units to communicate directly with one or more other unit from the same station without tying up the Dispatch channel. Each L-TAC channel cooresponds with (and is secondary to) one or more dispatch channels.

County Services Bureau (CSB) Hospital security operations also utilize County's 800Mhz trunked CWIRS and in hospital 800Mhz non-trunked standalone radio systems.   See respective istings under Trunked Radio System and Hospital headers in Database below.

Area Tactical (or "A-TAC") channels are used to coordinate significant incidents requiring the participation of units from more than one station.

Incidents or events that require countywide coordination use a Countywide Tactical (or 'C-TAC') channel.

County Service Burea(OCS) and Parks Bureau(PBK) utilize Countywide L-Tac.

The LASD Star Tacs are used for special events, tactical situations & investigations. Most are simply reallocations of the old Investigations (INV) channels.

Each S-TAC repeater pair (4, 9, 14 and 19) can be used in repeater mode, simplex on the output freq with two CTCSS tones or simplex on the input freq with two CTCSS tones. This gives the ability to use the channel as a repeater, or as a four simplex channels for operations in different parts of the county. S-TAC 2 & 3 are repeater operation only.

Each of five Mutual Aid channels covers a different part of the county and allows sheriff's units to coordinate with neighboring municipal police departments when one agency is assisting another. Note that LASD will also use "LAPD Access" (in the LAPD section) when providing mutual aid to the city of Los Angeles.

As default many County Jail and Corrrection Facilities utilize Court Services (CTS) simplex frequencies 

Volunteer organization administered by the Sheriff Department Emergency Operations Bureau to provide back-up disaster relief communications.

LA County FD Battalion Response Map

LAC Lifeguard sections:

North - Headquartered at Zuma Beach and provides ocean lifeguard services between Big Rock(Malibu) and Nicholas Canyon (Ventura County line)

Central - Headquartered next to the Santa Monica pier, provides services from Las Tunas(Malibu) Southward till Marina Del Rey.

South - Headquartered at Hermosa Beach, provides service from the Southern jetty of Marina Del Rey to San Pedro. 

Rescue Boat Section - Headquartered in Marina Del Rey, provides rescue boat service for all three beach sections and Catalina Island.

Seconday VHF/UHF radio system utilized by County departments in areas of limited reception of County CWIRS trunked system.

LARTCS provides direct communication interoperability between Law Enforcement, Fire, EMS, Federal, State and Military agencies at the scene of a major, multi-agency incident.

LARTCS has ability to cross-connects different radio channels over various radio frequency bands, throughout Los Angeles and surrounding counties.

Besides below listed frequencies LARTCS member agencies can utilize LASD Mutual Aid frequency pairs, 800Mhz I-CALL/I-TAC frequencies, 155.475 NALEMARS, VHF/UHF CLEMARS and Marine channel 83A as required.

User Choice: Simplex / Repeated.

Various Divisions

Utilized as overflow tacticals and by speciality units such as LAX Crash Trucks in day to day ops (most often in simplex mode).

Non Trunked Fallback and Talkaround Frequencies Supplementary to Municipal Services TRS.

Ontario Airport is owned and operated by Los Angeles World Airports, the department overseeing airports in the City of Los Angeles. For frequencies, see San Bernardino, County of (Public Safety) 09 System.

For Law enforcement, see Los Angeles County Sheriff Department.   For Fire/EMS see Los Angeles County (Fire/EMS)

Fire Department: see the Verdugo Fire Communications Authority

See Verdugo Fire Communications Authority for fire frequencies.

For Law enforcement, see the Los Angeles County Sheriff's Dept.  For Fire/EMS see Los Angeles, County of (Fire/EMS)

Law Enforcement is provided by the Los Angeles County Sheriff Department.

Avalon Fire Dept. is dispatched via the Avalon Sheriff's station desk.

Fire dispatched by Los Angeles, County of (Fire/EMS)

Police Unit Id's: #20-29 Day Shift, #30-39 Night Shift, #209 Dispatch

See Los Angeles, County of (Fire/EMS) for Fire/EMS Operations

For Fire/EMS see Los Angeles, County of (Fire/EMS)

Fire / EMS Services are provided by the Los Angeles County Fire Dept

For Law enforcement, see Los Angeles County Sheriff Department.   For Fire/EMS see Los Angeles County (Fire/EMS)