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CB Radio In The United States
In the United States, the Citizens Band Radio Service (CBRS), commonly called citizens band radio (CB radio), is one of several personal radio services defined under Title 47 of the Code of Federal Regulations, Part 95. It is intended to be a two-way voice communication service for use in personal and business activities of the general public, and has a reliable communications range of several miles, though the range is highly dependent on type of radio, antenna and propagation. CB radio is most frequently used by long-haul truck drivers for everything from relaying information regarding road conditions, the location of speed traps and other travel information, to basic socializing and friendly chatter. CB radio is also frequently used on larger farms for communication between machinery operators. Origins As originally constituted, what is now CB radio was Class D of the Citizens' Radio Service. Classes A and B were in the UHF radio band and served a similar purpose as Class D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recreational Vehicle
A recreational vehicle, often abbreviated as RV, is a motor vehicle or trailer that includes living quarters designed for accommodation. Types of RVs include motorhomes, campervans, coaches, caravans (also known as travel trailers and camper trailers), fifth-wheel trailers, popup campers, and truck campers. Features Typical amenities of an RV include a kitchen, a bathroom, and one or more sleeping facilities. RVs can range from utilitarian – containing only sleeping quarters and basic cooking facilities – to luxurious, with features like air conditioning (AC), water heaters, televisions and satellite receivers, and quartz countertops, for example. RVs can either be trailers (which are towed behind motor vehicles) or self-propelled vehicles. Most RVs are single-deck; however, double-deck RVs also exist. To allow a more compact size while in transit, larger RVs often have expandable sides (called slide-outs) or canopies that are deployed when stationary. History T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Government Of The United States
The federal government of the United States (U.S. federal government or U.S. government) is the national government of the United States, a federal republic located primarily in North America, composed of 50 states, a city within a federal district (the city of Washington in the District of Columbia, where most of the federal government is based), five major self-governing territories and several island possessions. The federal government, sometimes simply referred to as Washington, is composed of three distinct branches: legislative, executive, and judicial, whose powers are vested by the U.S. Constitution in the Congress, the president and the federal courts, respectively. The powers and duties of these branches are further defined by acts of Congress, including the creation of executive departments and courts inferior to the Supreme Court. Naming The full name of the republic is "United States of America". No other name appears in the Constitution, and this i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freebanding
Citizens band radio (also known as CB radio), used in many countries, is a land mobile radio system, a system allowing short-distance person-to-many persons bidirectional voice communication among individuals, using two way radios operating on 40 channels near 27 MHz (11 m) in the high frequency (a.k.a. shortwave) band. Citizens band is distinct from other personal radio service allocations such as FRS, GMRS, MURS, UHF CB and the Amateur Radio Service ( "ham" radio). In many countries, CB operation does not require a license, and (unlike amateur radio) it may be used for business or personal communications. Like many other land mobile radio services, multiple radios in a local area share a single frequency channel, but only one can transmit at a time. The radio is normally in receive mode to receive transmissions of other radios on the channel; when users want to talk they press a "push to talk" button on their radio, which turns on their transmitter. Users on a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diathermy
Diathermy is electrically induced heat or the use of high-frequency electromagnetic currents as a form of physical therapy and in surgical procedures. The earliest observations on the reactions of high-frequency electromagnetic currents upon the human organism were made by Jacques Arsene d'Arsonval. The field was pioneered in 1907 by German physician Karl Franz Nagelschmidt, who coined the term ''diathermy'' from the Greek words ''dia'' and θέρμη ''therma'', literally meaning "heating through" (adj., diather´mal, diather´mic). Diathermy is commonly used for muscle relaxation, and to induce deep heating in tissue for therapeutic purposes in medicine. It is used in physical therapy to deliver moderate heat directly to pathologic lesions in the deeper tissues of the body. Diathermy is produced by three techniques: ultrasound (''ultrasonic diathermy''), short-wave radio frequencies in the range 1–100 MHz (''shortwave diathermy'') or microwaves typically in the 915&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Induction Welding
Induction welding is a form of welding that uses electromagnetic induction to heat the workpiece. The welding apparatus contains an induction coil that is energised with a radio-frequency electric current. This generates a high-frequency electromagnetic field that acts on either an electrically conductive or a ferromagnetic workpiece. In an electrically conductive workpiece, the main heating effect is resistive heating, which is due to induced currents called eddy currents. In a ferromagnetic workpiece, the heating is caused mainly by hysteresis, as the electromagnetic field repeatedly distorts the magnetic domains of the ferromagnetic material. In practice, most materials undergo a combination of these two effects. Nonmagnetic materials and electrical insulators such as plastics can be induction-welded by implanting them with metallic or ferromagnetic compounds, called susceptors, that absorb the electromagnetic energy from the induction coil, become hot, and lose their heat to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISM Band
The ISM radio bands are portions of the radio spectrum reserved internationally for industrial, scientific and medical (ISM) purposes, excluding applications in telecommunications. Examples of applications for the use of radio frequency (RF) energy in these bands include radio-frequency process heating, microwave ovens, and medical diathermy machines. The powerful emissions of these devices can create electromagnetic interference and disrupt radio communication using the same frequency, so these devices are limited to certain bands of frequencies. In general, communications equipment operating in ISM bands must tolerate any interference generated by ISM applications, and users have no regulatory protection from ISM device operation in these bands. Despite the intent of the original allocations, in recent years the fastest-growing use of these bands has been for short-range, low power wireless communications systems, since these bands are often approved for such devices, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Line Communication
Power-line communication (also known as power-line carrier or PLC) carries data on a conductor that is also used simultaneously for AC electric power transmission or electric power distribution to consumers. A wide range of power-line communication technologies are needed for different applications, ranging from home automation to Internet access which is often called broadband over power lines (BPL). Most PLC technologies limit themselves to one type of wires (such as premises wiring within a single building), but some can cross between two levels (for example, both the distribution network and premises wiring). Typically transformers prevent propagating the signal, which requires multiple technologies to form very large networks. Various data rates and frequencies are used in different situations. A number of difficult technical problems are common between wireless and power-line communication, notably those of spread spectrum radio signals operating in a crowded environment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Part 15 (FCC Rules)
Code of Federal Regulations, 'Title 47, Part 15(47 CFR 15) is an oft-quoted part of Federal Communications Commission (FCC) rules and regulations regarding unlicensed transmissions. It is a part of Title 47 of the Code of Federal Regulations (CFR), and regulates everything from spurious emissions to unlicensed low-power broadcasting. Nearly every electronics device sold inside the United States radiates unintentional emissions, and must be reviewed to comply with Part 15 before it can be advertised or sold in the US market. Subparts A - General Subpart A includes 21 sections from 15.1 to 15.38. states that any radiator (that which emits radio energy), whether or not intentional, must be licensed unless it meets 47 CFR 15 or is otherwise exempted by the FCC. the definitions are defined by the definition given. contains a general provision that devices may not cause interference and must accept any interference received. You are cautioned that any changes or modificatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
6-meter Band
The 6-meter band is the lowest portion of the very high frequency (VHF) radio spectrum internationally allocated to amateur radio use. The term refers to the average signal wavelength of 6 meters. Although located in the lower portion of the VHF band, it nonetheless occasionally displays propagation mechanisms characteristic of the high frequency (HF) bands. This normally occurs close to sunspot maximum, when solar activity increases ionization levels in the upper atmosphere. During the sunspot peak of 2005, worldwide 6 meter propagation occurred making 6 meter communications as good as or in some instances and locations, better than HF frequencies. The prevalence of HF characteristics on this VHF band has inspired amateur operators to dub it the "magic band". In the northern hemisphere, activity peaks from May through early August, when regular sporadic E propagation enables long-distance contacts spanning up to for single-hop propagation. Multiple-hop sporadic& ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio-controlled Model
A radio-controlled model (or RC model) is a Physical model, model that is steering, steerable with the use of radio control. All types of model vehicles have had RC systems installed in them, including radio-controlled car, ground vehicles, radio-controlled boat, boats, radio-controlled airplane, planes, Radio-controlled helicopter, helicopters and even radio-controlled submarine, submarines and scale railway locomotives. History Radio control has been around since Nikola Tesla demonstrated a remote control boat in 1898. World War II saw increased development in radio control technology. The Luftwaffe used controllable winged bombs for targeting Allies of World War II, Allied ships. During the 1930s the Good brothers Bill and Walt pioneered vacuum tube based control units for R/C hobby use. Their "Guff" radio controlled plane is on display at the National Aerospace museum. Ed Lorenze published a design in Model Airplane News that was built by many hobbyists. Later, after WW2, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Emergency Associated Communication Teams
REACT (Radio Emergency Associated Communication Teams) began as a CB radio Emergency Channel 9 monitoring organization across the United States and Canada in 1962. Initially, the primary role of REACT volunteers was to monitor Channel 9, the CB Emergency Channel, to help motorists. Later, duties grew to include communications after disasters (such as tornadoes and floods), and in some places before disasters (storm spotting). As well, REACT safety communications for parades, runs/walks and other community events became prominent. Now, REACT Teams barely use CB primarily, a large percentage have now added amateur, FRS, GMRS, Multi-Use Radio Service (MURS), Trunked radio systems and business band radio ( LMR) to their public service capabilities. Their original purpose, to monitor CB, has largely gone by the wayside. Services Provided Each REACT Team is unique and fills a local purpose. The original purpose of monitoring Emergency Channel 9 for distress calls is not as needed as i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
