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A HISTORY OF SAND DIEGO POLICE COMMUNICATIONS
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A HISTORY OF SAND DIEGO POLICE COMMUNICATIONS
Source: Monitoring Times Sept. 1990
By: Brian Johnson III
Reprinted by: John (Topol) Johnson, KWV8BP
The Hotline BBS 304-736-9169
This file has been split into two parts, this part will contain the article
part 2 will contain the frequencies and call signs..
Back in the early part of this century, when the top brass at the San Diego
Police Department wanted to get in touch with a cop on the beat, they communicated by light rather radio.
At headquarters, a signal from a switchboard would activate a flashing red light bulb atop the callon the officer's beat. Seeing the light flash, the officer would then use the call box to phone akt eadquarters for more information. Known as the Gamewell Light System, it was effective but ltte or. elying as it did on the beat officer's eye to spot the signal, there was no guarantee ofa qickresons.
That's why one day in 1927, the squad room at SDPD was abuzz. Chief Joseph V. Doran had announced pfor the department to begin using radio. Two years later, Doran's successor, Arthur R. Hill, prooe ong away with the old Gamewell Light System altogether. Replacing the light and call box woul b atrnsitter which would send one-way radio messages to patrol cars equipped with receivers.
THen, in 1932, the idea of using radio in patrol cars got serious. Chief Harry A. Scott announced twenty police vehicles would be equipped for coverage around the clock. This included two police nt n an ambulance
for East San Diego, five units for the beaches and northern areas of the city including downtown andn others for additional areas thoughout the city. Only five cars, however, would be equipped in h eining. That year, city officials began soliciting bids for a broadcasting station in Balboa Prkner hehub of the city.
The first so-called "radio cops" began receiving dispatched messages at 2 p.m. on the afternoon of ber 1, 1932, when station KGZD went on the air. Utilizing a 100 watt transmitter housed in a conrt lck building in Balboa Park just north of the city shops complex, the first broadcast was typcalysucict: "KGZD is now on the air: stand-by for further broadcast."
KGZD did not achieve its dream of 24 hour operation right away, instead going on the air each day f p.m. until 6 a.m.. Two dispatchers were on duty at all times, their job being to take the messae add down from central headquarters and relay them over the air to cars and stations. No radio ods er ued by dipatchers then but each letter of the alphabet was given a name to ward off possile istkes Thse letters were most often used in the broadcast of automobile license numbers.
The first five cars to receive radios were Ford Model A's. And what a change it made. With the intrion of radio, the response time to an event was quickened. Simultaneously, headquarters could no e ntouch with the beat cop by radioing him a message -- remember that the system was one-way ony - ndwat for him to get to the nearest call box and ring up headquarters. The frequency used bytheSanDieo Plice Department in those days: 2,490 Kilohertz.
While radio did serve to launch the San Diego Police Department into the 20th century, the system wt without its problems. Primary among them was the fact that since it was indeed a one-way syste,n n at headquarters knew what happened once the dispatch was made. Headquarters could, of cours, ai uti the officer returned to at the end of his shift or hope that the officer would get in tuchviathecal box.
Police Chief George Sears continued the department's push into the 20th century in 1936 when he mad one-way system two-way. Now the radio equipped car could not only receive; Now it could talk baka el. A new frequency was established for the purpose: 37.02 megahertz in the low VHF band. Evetull, vey car in the field would be equipped with transmitting and receiving equipment based on Weter Elctrc design and built by the San Diego Electrical Division.
Knowing a good thing when they saw it, other government agencies in the area jumped on the San Diegs radio bandwagon. Before long, 2,940 KHz got crowded. At any time, an important police call migtb nerrupted by a transmission from the San Diego Fire Department, the Chula Vista Police Departen, heSa Digo County Sheriff's Department and the California Highway Patrol.
Eventually, each agency did obtain its own transmitting and receiving frequency. First to abandon 2was the San Diego Fire Department which left for 154.310 MHz in the high VHF band. Others followdadb April 19, 1961, even the frequency's original owner had left, converting over to FM equipmet eaurngboth "talk-out" and "talk-back" capabilities. The next year, the City Electrical Divisio deignd ad bilt a new dispatch center for the police department at 801 West Market Street, severng amostall ies o its radio pioneering past.
The new radio center was a state of the art "remote" electronics system. There were three dispatch les and ten radio channels with expansion capacity to five consoles. A second "talk-out" channelwsipemented which bisected the city, resulting in more flexible use of radio equipment. The veryfisthih HF frequency used by San Diego police was 158.730 MHz. This system operated flawlessly utillat 194 wen a new Motorola system was installed in the city operations building at 1220 FirstAvene.
Today, the San Diego Police Department has six operational frequencies in the high VHF band. Each hs a separate area of the city. In addition, there is also an inquiry channel used primarily to ofrasstance for officers running warrant checks, among other functions such as requesting the disathe t cll the owner of a business regarding a break-in or burglary.
For use in the field, officers working on a special detail use the tactical channel for surveillancrations or during traffic re-routing and control during times of unusually heavy pedestrian and eil raffic. SDPD detectives use yet another frequency that is specifically set aside for their oertins Secial Weapons and Tactical (SWAT) units have another.
Because San Diego is in a coastal valley surrounded by hilly terrain, transceiver/repeater locatione been placed on mountain tops (although some are inside the city itself.) The current system isdsge for line-of-sight communications. It is also voted, whereby the best signal from a unit in hefildiscaptured by the receiver closest to that signal. It is then transmitted to the dispatch entr.
The San Diego Police Department has about 1,024 vehicles in the fleet. Police cruisers and motorcycits are all equipped with Motorola or GE (General Electric) mobile radios. This system also incldshnie-talkies.
ALl car radios have the full complement of operational frequencies but some don't have the capabili transmitting on detective (154.725 MHz) or NALEMARS (155.475 MHz) channels. All SDPD vehicles d aeCEMARS (154.920 MHz) and tactical (155.685 MHz) capabilities.
In case of a break down at the main dispatch center, emergency back-up communications can be handlea command van in the field. This converted GMC bus is fitted with all the main frequencies and cnoeae on its own power for 48 hours or two weeks with outside electricity.
Dispatchers in the massive underground communications center, presently located in the City Operatiuilding, use Motorola Centracom consoles with the cpability of 20 channels. In addition, the conoe r equipped with two computer systems which monitor the status of police units along with eachphnean rdio room postition.
Phone operators man 18 positions while dispatchers are equipped with six consoles to provide adequaverage for all areas of the city. The phone room, which includes 911 operators, is serarate fromtemi dispatch room.
In the radio room there are also two supervisor consoles and one entry position console. Each was baround the original Motorola design. However according to Paul Salter, senior communications engne ih the city, "Electronically, they are remote consoles with the main components located in anthr oo ustairs." This, according to Salter, eliminates the prblem of bothering dispatchers when epars aveto e made in the electronic circuitry. Maintaining the present communications system rus abut 3,000per ear.
During the 1900s, the San Diego Police Department was among the pioneers of radio communications. Tetain their cutting edge by continuously fine tuning and improving the system, their plans for tenx ouple of years confirming their dedication to providing the best possible service to the comunty Ane 800 MHz trunked system and a new location in the Police Headquarters Building at 1401 Boaday n te sring of 1991. Geographically, that's not all that far from where Chief Joseph V. Dorn fist poposd th revolutionary idea of equipping patrol cars with radios. Technologically, thoug, it' abou as fr apat as dinosaurs and space shuttles. Chief Doran would be proud.
See part 2 of this file for Frequencies and Radio Code.
This file was brought to you by John Johnson, KWV8BP of The Hotline BBS,
we have many Scanner & Radio Related files, check us out at 304-736-9169.
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