Scanner (radio)

PSR-800 GRE Digital trunking scanner

Uniden BCT-15 base/mobile trunktracking scanner

A scanner is a radio receiver that can automatically tune, or scan, two or more discrete frequencies, stopping when it finds a signal on one of them and then continuing to scan other frequencies when the initial transmission ceases.

The terms radio scanner or police scanner generally refer to a communications receiver that is primarily intended for monitoring VHF and UHF landmobile radio systems, as opposed to, say, a receiver used to monitor international shortwave transmissions.

More often than not, these scanners can also tune to different types of modulation as well (AM, FM, WFM, etc). Early scanners were slow, bulky, and expensive. Today, modern microprocessors have enabled scanners to store thousands of channels and monitor hundreds of channels per second. Recent models can follow trunked radio systems and decode APCO-P25 digital transmissions. Both hand held and desktop models are available. Scanners are often used to monitor police, fire and emergency medical services. Radio scanning serves an important role in the fields of journalism and crime investigation, as well as a hobby for many people around the world.

History and use

Scanners developed from earlier tunable and fixed-frequency radios that received one frequency at a time. Non-broadcast radio systems, such as those used by public safety agencies, do not transmit continuously. With a radio fixed on a single frequency, much time could pass between transmissions, while other frequencies might be active. A scanning radio will sequentially monitor multiple programmed channels, or search between user defined frequency limits. The scanner will stop on an active frequency strong enough to break the radio's squelch setting and resume scanning other frequencies when that activity ceases.

Scanners are used by hobbyists, railfans, off duty emergency services personnel, reporters, and criminals.

Scanners first became popular and widely available during CB Radio's heyday in the 1970s. The first scanners often had between four and ten channels and required the purchase of a separate crystal for each frequency received. Modern programmable scanners ^[1] – an early 1976 US entry was the Tennelec MCP-1 ^[2][3] – allow hundreds or thousands of frequencies to be entered via a keypad and stored in various 'memory banks' and can scan at a rapid rate due to modern microprocessors.

A hand-held wide band communications receiver.

Many recent models will allow scanning of the specific DCS or CTCSS code used on a specific frequency should it have multiple users. One memory bank can be assigned to air traffic control, another can be for local marine communications, and yet another for local police frequencies. These can be switched on and off depending on the user's preference. Most scanners have a weather radio band, allowing the listener to tune into weather radio broadcasts from a NOAA transmitter.

Some scanners are equipped with Fire-Tone out. Fire tone out decodes Quik call II tones and acts as a pager when the correct sequence of tones is detected.

Active frequencies can be found by searching the internet and frequency reference books or can be discovered through a programmable scanner's search function. An external antenna for a desktop scanner or an extendable antenna for a hand held unit will provide greater performance than the original equipment antennas provided by manufacturers.

Many scanner clubs exist to allow members to share information about frequencies, codes and operations. Most have Internet presence, such as websites, email lists or Web forums. The Southern California Monitoring Association (SCMA), The All Ohio Scanner Club, Chicago Area Radio Monitoring Association and RadioReference.com are examples of these.

Legal issues in the US

New York and Florida currently prohibit scanners installed in a vehicle unless the operator has an FCC issued radio license

The legality of radio scanners varies considerably between jurisdictions. In the United States it is a federal crime to monitor cellular phone calls. Some US states prohibit the use of a scanner in an automobile. Although scanners capable of following trunked radio systems and demodulating some digital radio systems such as APCO Project 25 are available, decryption-capable scanners would be a violation of United States law and possibly laws of other countries.^{[citation needed]}

A law passed by the Congress of the United States, under the pressure from cellular telephone interests, prohibited scanners sold after a certain date from receiving frequencies allocated to the Cellular Radio Service. The law was later amended to make it illegal to modify radios to receive those frequencies, and also to sell radios that could be easily modified to do so.^[4] This law remains in effect even though few cellular subscribers still use analogue technology. There are Canadian and European unblocked versions available, but these are illegal to import into the U.S. Frequencies used by early cordless phones at 43.720–44.480 MHz, 46.610–46.930 MHz, and 902.000–906.000 MHz can be picked up by many scanners. The proliferation of scanners led most cordless phone manufacturers to produce cordless handsets operating on a more secure 2.4 GHz system using spread-spectrum technology. Certain states in the U.S., such as New York and Florida, prohibit the use of scanners in a vehicle unless the operator has a radio license issued from the Federal Communications Commission (FCC) (Amateur Radio, etc.)^[5][6] or the operator's job requires the use of a scanner in a vehicle (e.g., police, fire, utilities).^{[citation needed]}

In some parts of the United States, there are extra penalties for the possession of a scanner during a crime, and some states, such as Michigan, also prohibit the possession of a scanner by a person who has been convicted of a felony in the last 5 years.^[7]

In the United States, the general guidelines^{[clarification needed]} to follow when using a radio scanner are that it is illegal to:^{[citation needed]}

• listen in on cellular and cordless phone calls
• intercept encrypted or scrambled communications
• sell or import radio scanners that are capable of receiving cellular phone frequencies (this rule does not apply to sales by individuals^{[citation needed]} and radio scanners made before the ban)
• modify radio scanners so that cellular phone frequencies can be received
• use information received for personal gain (a common example is where a taxi driver listens to a competitor's dispatch channel to steal a customer)
• use information received to aid in the commission or execution of a crime
• disclose information received to other persons

Licensed Amateur Radio Operators with a valid FCC License may possess Amateur Radio Transceivers capable of reception beyond the Amateur Radio Bands per an FCC Memorandum & Order known as FCC Docket PR91-36 (also known as FCC 93-410).^[8][9]

Florida

843.16 Unlawful to install or transport radio equipment using assigned frequency of state or law enforcement officers; definitions; exceptions; penalties.-- (1) A person, firm, or corporation may not install or transport in any motor vehicle or business establishment, except an emergency vehicle or crime watch vehicle as herein defined or a place established by municipal, county, state, or federal authority for governmental purposes, any frequency modulation radio receiving equipment so adjusted or tuned as to receive messages or signals on frequencies assigned by the Federal Communications Commission to police or law enforcement officers or fire rescue personnel of any city or county of the state or to the state or any of its agencies. Provided, nothing herein shall be construed to affect any radio station licensed by the Federal Communications System or to affect any recognized newspaper or news publication engaged in covering the news on a full-time basis or any alarm system contractor certified pursuant to part II of chapter 489, operating a central monitoring system. (3) This section does not apply to the following: (a) Any holder of a valid amateur radio operator or station license issued by the Federal Communications Commission. (b) Any recognized newspaper or news publication engaged in covering the news on a full-time basis. (c) Any alarm system contractor certified pursuant to part II of chapter 489, operating a central monitoring system. (d) Any sworn law enforcement officer as defined in s. 943.10 or emergency service employee as defined in s. 496.404 while using personal transportation to and from work. (e) An employee of a government agency that holds a valid Federal Communications Commission station license or that has a valid agreement or contract allowing access to another agency's radio station. (4) Any person, firm, or corporation violating any of the provisions of this section commits a misdemeanor of the first degree, punishable as provided in s. 775.082 or s. 775.083.

Indiana

Interference With Governmental Operations s. 35-44-3-12—Possession of police radios -- (a) A person who knowingly or intentionally: (1) Possesses a police radio; (2) Transmits over a frequency assigned for police emergency purposes; or (3) Possesses or uses a police radio: (A) While committing a crime; (B) To further the commission of a crime; or (C) To avoid detection by a law enforcement agency; commits unlawful use of a police radio, a Class B misdemeanor. (b) Subsection (a)(1) and (a)(2) do not apply to: (1) A governmental entity; (2) A regularly employed law-enforcement officer; (3) A common carrier of persons for hire whose vehicles are used in emergency service; (4) A public service or utility company whose vehicles are used in emergency service; (5) A person who has written permission from the chief executive officer of a law enforcement agency to possess a police radio; (6) A person who holds an amateur radio license issued by the Federal Communications Commission if the person is not transmitting over a frequency assigned for police emergency purposes; (7) A person who uses a police radio only in the person's dwelling or place of business; (8) A person: (A) Who is regularly engaged in newsgathering activities; (B) Who is employed by a newspaper qualified to receive legal advertisements under IC 5-3-1, a wire service, or a licensed commercial or public radio or television station; and (C) Whose name is furnished by his employer to the chief executive officer of a law enforcement agency in the county in which the employer's principal office is located; (9) A person engaged in the business of manufacturing or selling police radios; or (10) A person who possesses or uses a police radio during the normal course of the person's lawful business.

Kentucky

Kentucky Revised Statute (K.R.S.) 432.570, which states that, "it shall be unlawful for any person except a member of a police department or police force or an official with written authorization from the head of a department which regularly maintains a police radio system authorized or licensed by the Federal Communications Commission, to have in his or her possession or in an automobile or other vehicle, or to equip install in or on any automobile or other vehicle, any mobile radio set or apparatus capable of either receiving or transmitting radio or other messages or signals within the wave length or channel now or which may hereafter be allocated by the Federal Communications Commission or its successor, for the purpose of police radios, or which may in any way intercept or interfere with the transmission of radio messages by any police or other peace officers.

Minnesota

299C.37 POLICE COMMUNICATION EQUIPMENT; USE, SALE. Subdivision 1.Use regulated. (a) No person other than peace officers within the state, the members of the State Patrol, and persons who hold an amateur radio license issued by the Federal Communications Commission, shall equip any motor vehicle with any radio equipment or combination of equipment, capable of receiving any radio signal, message, or information from any police emergency frequency, or install, use, or possess the equipment in a motor vehicle without permission from the superintendent of the bureau upon a form prescribed by the superintendent.

Legal issues in other countries

Canada

According to the Radiocommunication Act,^[10] it is completely legal to install, operate or possess a radio apparatus that is capable only of the reception of broadcasting (digital and analog, but not encrypted data) provided that private information is not passed on or disclosed to any other person(s) or party(s).

New Zealand

According to the Radiocommunications Act 1989^[11] it is legal to possess and use a scanner at any time to tune to any private voice radio (not encrypted data) provided that private information is not passed on or disclosed to any other person(s) or party(s).

Australia

It is legal to possess a scanner. It is legal to listen to any transmission that is not classified as telecommunication (i.e. anything not connected to the telephone network).

Mexico

It is legal to have an unblocked scanner and listen to any radio spectrum frequencies including encrypted and cellular band. According to the Federal Law of General Ways of Communication individuals are prohibited from spreading any information obtained via the mass media.

Brazil

It is legal to have a scanner, but the user should have a ham radio license. Individuals are prohibited from spreading or recording any information obtained.

See also

Electronics portal

• Two-way radio
• Trunked radio system
• Communications receiver
• Chicago Area Radio Monitoring Association

References

1. ^ A US patent [1] was issued to Peter W. Pflasterer on June 1, 1976.
2. ^ "Tennelec". allexperts.com/. http://www.associatepublisher.com/e/t/te/tennelec.htm. Retrieved 1 June 2011. . Sold at the January, 1976 Consumer Electronics Show in Chicago.
3. ^ Curtis,, Anthony R. (July 1977). "Computerized scanners". Popular Mechanics 148 (1): 68–70. http://books.google.com/books?id=tOIDAAAAMBAJ&pg=PA70. Retrieved 1 June 2011. 
4. ^ FCC (1997-07-10). DA 97-1440: Manufacturing Illegal Scanners Includes Scanner Modification. Federal Communications Commission, 10 July 1997. Retrieved from http://www.fcc.gov/Bureaus/Engineering_Technology/Public_Notices/1997/da971440.txt.
5. ^ http://public.leginfo.state.ny.us/menugetf.cgi §397 Equipping motor vehicles with radio receiving sets
6. ^ Statutes & Constitution :View Statutes : Online Sunshine
7. ^ Michigan Penal Code, Excerpt
8. ^ FCC (1993-09-03). PR Docket 91-36: In the Matter of Federal Preemption of State and Local Laws Concerning Amateur Operator Use of Transceivers Capable of Reception Beyond Amateur Service Frequency Allocations - Memorandum Opinion and Order. Federal Communications Commission, 3 September 1993. Retrieved from http://www.arrl.org/announce/regulatory/pr91-36/pr91-36.html.
9. ^ A partial copy of the Electronic Communications Privacy Act of 1986 can be found at http://floridalawfirm.com/privacy.html with the following disclaimer: "This document was originally published by Florida Law Firm in 1998. It is no longer current and should not be relied upon for any reason."
10. ^ Radiocommunication Act: An Act respecting radiocommunication in Canada. R.S., 1985, c. R-2, s. 1; 1989, c. 17, s. 2.
11. ^ Radiocommunications Act 1989

External links

• Scanning at the Open Directory Project

Radio frequency sources

• Global Frequency Database
• Frequency Database for Ireland
• RadioReference Source of frequencies in the United States and several other countries
• Frequency Database for Ireland
• Frequency Database for Germany (English/German)
• United States Federal Communications Commission FCC searchable database of licensed radio frequencies
• Australian Communications and Media Authority ACMA searchable database of licensed frequencies and users
• FlightRadio.com - Aircraft frequencies
• AirNav - Airports
• Scanning In Tasmania, Australia
• UK Scanning Frequency Database and Scanning Information
• National Communicatins Magazine Includes scanner magazine with entire FCC and beyond database

Scanner laws

• Mobile Scanner & Radar Detector Laws in the U.S.
• Radio Communications Legislation in Australia - including the use of scanners

Other links

• A FAQ for scanner users
• Incident Broadcast Network - Live scanner feeds