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Police Scanner
A radio scanner or simply scanner is a radio receiver that can automatically tune discrete frequencies, scanning over a frequency band to find a signal until the initial transmission ceases. The term ''scanner'' generally refers to a communications receiver that is primarily intended for monitoring VHF and UHF landmobile radio systems, as opposed to, for instance, a receiver used to monitor international shortwave transmissions, although these may be classified as scanners too. More often than not, these scanners can also tune to different types of modulation as well ( AM, FM, SSB, 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 servi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ICOM IC-R5 2
ICOM may refer to: * International Council of Museums * Idaho College of Osteopathic Medicine, a medical school in the United States * Icom Incorporated, radio equipment manufacturer * Industrial Common Ownership Movement (ICOM), a co-operative federation that now forms part of Co-operatives UK * Inputs, Controls, Outputs, and Mechanisms (ICOM), the conceptual parts of the IDEF0 function modeling methodology * ICOM Simulations, software company * ICOM Tele A/S, a Danish telecommunications operator {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journalism
Journalism is the production and distribution of reports on the interaction of events, facts, ideas, and people that are the "news of the day" and that informs society to at least some degree of accuracy. The word, a noun, applies to the journalist, occupation (professional or not), the methods of gathering information, and the organizing literary styles. The appropriate role for journalism varies from country to country, as do perceptions of the profession, and the resulting status. In some nations, the news media are controlled by government and are not independent. In others, news media are independent of the government and operate as private industry. In addition, countries may have differing implementations of laws handling the freedom of speech, freedom of the press as well as slander and Libel, libel cases. The proliferation of the Internet and smartphones has brought significant changes to the media landscape since the turn of the 21st century. This has created a shif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NOAA Weather Radio All Hazards
NOAA Weather Radio (NWR), also known as NOAA Weather Radio All Hazards, is an automated 24-hour network of VHF FM weather radio stations in the United States which broadcast weather information directly from a nearby National Weather Service office. Its routine programming cycle includes local or regional weather forecasts, synopsis, climate summaries or zone/lake/coastal waters forecasts, and can be shortened to specifically include hazardous weather outlooks, short-term forecasts, special weather statements or tropical weather summaries during hazardous weather events. It occasionally broadcasts other non-weather related events such as national security statements, natural disaster information, environmental and public safety statements such as AMBER Alerts, civil emergencies, fires, evacuation orders, and other hazards sourced from the Federal Communications Commission's (FCC) Emergency Alert System. NOAA Weather Radio uses automated broadcast technology that allows for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine (ocean)
The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian, Antarctic/Southern, and Arctic Ocean),"Ocean." ''Merriam-Webster.com Dictionary'', Merriam-Webster, https://www.merriam-webster.com/dictionary/ocean . Accessed March 14, 2021. and are themselves mostly divided into seas, gulfs and subsequent bodies of water. The ocean contains 97% of [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Traffic Control
Air traffic control (ATC) is a service provided by ground-based air traffic controllers who direct aircraft on the ground and through a given section of controlled airspace, and can provide advisory services to aircraft in non-controlled airspace. The primary purpose of ATC is to prevent collisions, organise and expedite the flow of traffic in the air, and provide information and other support for pilots. Personnel of air traffic control monitor aircraft location in their assigned airspace by radar and communicate with the pilots by radio. To prevent collisions, ATC enforces Separation (air traffic control), traffic separation rules, which ensure each aircraft maintains a minimum amount of 'empty space' around it at all times. It is also common for ATC to provide services to all General aviation, private, Military aviation, military, and commercial aircraft operating within its airspace; not just civilian aircraft. Depending on the type of flight and the class of airspace, AT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CTCSS
In telecommunications, Continuous Tone-Coded Squelch System or CTCSS is one type of in-band signaling that is used to reduce the annoyance of listening to other users on a shared two-way radio communication channel. It is sometimes referred to as tone squelch or PL for Private Line, a trademark of Motorola. It does this by adding a low frequency audio tone to the voice. Where more than one group of users is on the same radio frequency (called ''co-channel users''), CTCSS circuitry mutes those users who are using a different CTCSS tone or no CTCSS. CTCSS tone codes are sometimes referred to as sub-channels, but this is a misnomer because no additional radio channels are created. All users with different CTCSS tones on the same channel are still transmitting on the identical radio frequency, and their transmissions interfere with each other; however; the interference is masked under most conditions. Although it provides some protection against interference, CTCSS does not offer a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital-Coded Squelch
In telecommunications, squelch is a circuit function that acts to suppress the audio (or video) output of a receiver in the absence of a strong input signal. Essentially, squelch is a specialized type of noise gate designed to suppress weak signals. Squelch is used in two-way radios and VHF/UHF radio scanners to eliminate the sound of noise when the radio is not receiving a desired transmission. Squelch In some designs, the squelch threshold is preset. For example, television squelch settings are usually preset. Receivers in base stations, or repeaters at remote mountain top sites, are usually not adjustable remotely from the control point. In two-way radios (also known as radiotelephones), the received signal level required to unsquelch (un-mute) the receiver may be fixed or adjustable with a knob or a sequence of button presses. Typically the operator will adjust the control until noise is heard, and then adjust in the opposite direction until the noise is squelched. At ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uniden BCT-15 Deck In Bracket-left
is a Japanese company in the wireless communication industry. History Uniden was established on February 7, 1966, by its founder Hidero Fujimoto as "Uni Electronics Corp". Uniden became a well-known brand in the 1970s by manufacturing and marketing millions of citizens band radios (CB), under the Uniden brand as well as other companies such as Midland and Realistic, which rebranded the equipment under their own labels. Uniden also marketed CB Radios in the UK under the Uniden and Uniace brands during the early '80s. During the 1980s, Uniden grew to become the world's largest manufacturer of cordless telephones in addition to television satellite equipment, mobile radios, advanced marine electronics and radio scanners (the latter under BearCat brand). In Europe, it became successful in the telecommunications market with its introduction of 900 MHz cordless telephones. As Uniden continued to grow and extend its international operations, Uniden Australia and Uniden New Ze ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Consumer Electronics Show
CES (; formerly an initialism for Consumer Electronics Show) is an annual trade show organized by the Consumer Technology Association (CTA). Held in January at the Las Vegas Convention Center in Winchester, Nevada, United States, the event typically hosts presentations of new products and technologies in the consumer electronics industry. History The first CES was held in June 1967 in New York City. It was a spin-off of the Chicago Music Show which, until then, had served as the main event for exhibiting consumer electronics. The event had 17,500 attendees and over 100 exhibitors; the kickoff speaker was Motorola chairman Bob Galvin. From 1978 to 1994, CES was held twice each year: once in January in Las Vegas as the ''Winter Consumer Electronics Show'' (WCES) and once in June in Chicago as the ''Summer Consumer Electronics Show'' (SCES). The winter show was held in Las Vegas in 1995 as planned. However, since the summer Chicago shows were beginning to lose popularity, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tennelec
Tennelec was a US electronics company founded in the early 1960s by Edward Fairstein in Oak Ridge, Tennessee. The company came to prominence producing instrumentation for nuclear studies and later, programmable scanning radios. The TC-200 amplifier was a successful early design that established Tennelec as a leader in the nuclear instrumentation field. Following on the heels of the TC-200 success, the company developed additional components necessary for precise nuclear measurement, including detectors and particle counters. Tennelec also manufactured innovative scanning radios in the 1970s. The first programmable radio scanner was the Memoryscan from Tennelec Commercial Products Division, introduced in 1974, and later known as the Memoryscan 1 (model MS-1). This was followed by a slightly improved model, the Memoryscan 2 (model MS-2). Prior to the MS-1 and MS-2, scanners were "programmed" by inserting a series of hand-cut crystals tuned for different frequencies. The scanner w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Oscillator
A crystal oscillator is an electronic oscillator Electrical circuit, circuit that uses a piezoelectricity, piezoelectric crystal as a frequency selective surface, frequency-selective element. The oscillator frequency is often used to keep track of time, as in quartz clock, quartz wristwatches, to provide a stable clock signal for digital data, digital integrated circuits, and to stabilize frequencies for radio transmitters and radio receiver, receivers. The most common type of piezoelectric resonator used is a quartz crystal, so oscillator circuits incorporating them became known as crystal oscillators. However, other piezoelectric materials including polycrystalline ceramics are used in similar circuits. A crystal oscillator relies on the slight change in shape of a quartz crystal under an electric field, a property known as inverse piezoelectricity. A voltage applied to the electrodes on the crystal causes it to change shape; when the voltage is removed, the crystal generates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Channel (communications)
A communication channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunications and computer networking. A channel is used for information transfer of, for example, a digital bit stream, from one or several '' senders'' to one or several '' receivers''. A channel has a certain capacity for transmitting information, often measured by its bandwidth in Hz or its data rate in bits per second. Communicating an information signal across distance requires some form of pathway or medium. These pathways, called communication channels, use two types of media: Transmission line-based telecommunications cable (e.g. twisted-pair, coaxial, and fiber-optic cable) and broadcast (e.g. microwave, satellite, radio, and infrared). In information theory, a channel refers to a theoretical ''channel model'' with certain error characteristics. In this more general view, a storage d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
