Misplaced Pages

#98901

130-415: One of the earliest spin-offs of the modern media era, if not the first, happened in 1941 when the supporting character Throckmorton P. Gildersleeve from the old time radio comedy show Fibber McGee and Molly became the star of his own program The Great Gildersleeve (1941–1957). A spin-off (also spelt spinoff) is derived from already existing works that focus on more details and different aspects from

260-471: A directional antenna transmits radio waves in a beam in a particular direction, or receives waves from only one direction. Radio waves travel at the speed of light in vacuum and at slightly lower velocity in air. The other types of electromagnetic waves besides radio waves, infrared , visible light , ultraviolet , X-rays and gamma rays , can also carry information and be used for communication. The wide use of radio waves for telecommunication

390-552: A mass hysteria from the (entirely fictional) radio presentation of The War of the Worlds , which had been presented as a faux newscast. The sponsored musical feature soon became one of the most popular program formats. Most early radio sponsorship came in the form of selling the naming rights to the program, as evidenced by such programs as The A&P Gypsies , Champion Spark Plug Hour , The Clicquot Club Eskimos , and King Biscuit Time ; commercials, as they are known in

520-418: A microphone , a video signal representing moving images from a video camera , or a digital signal consisting of a sequence of bits representing binary data from a computer. The modulation signal is applied to a radio transmitter . In the transmitter, an electronic oscillator generates an alternating current oscillating at a radio frequency , called the carrier wave because it serves to generate

650-497: A radar screen . Doppler radar can measure a moving object's velocity, by measuring the change in frequency of the return radio waves due to the Doppler effect . Radar sets mainly use high frequencies in the microwave bands, because these frequencies create strong reflections from objects the size of vehicles and can be focused into narrow beams with compact antennas. Parabolic (dish) antennas are widely used. In most radars

780-483: A radio network 's studios, or at the facilities of a network-owned or affiliated station, which might have four or more lathes. A small local station often had none. Two lathes were required to capture a program longer than 15 minutes without losing parts of it while discs were flipped over or changed, along with a trained technician to operate them and monitor the recording while it was being made. However, some surviving recordings were produced by local stations. When

910-404: A sidequel , a portmanteau of "side" (as in side-by-side) and " sequel ", when it occurs in the same timeframe as the original, sometimes contacting with the main narrative at points. In Japanese , the word gaiden ( 外伝 , pronounced [ɡaideɴ] , lit. "outside legends") also refers to such contemporaneous spin-offs and is frequently translated as "side story". Sometimes even when

1040-632: A transmitter connected to an antenna which radiates oscillating electrical energy, often characterized as a wave . They can be received by other antennas connected to a radio receiver ; this is the fundamental principle of radio communication. In addition to communication, radio is used for radar , radio navigation , remote control , remote sensing , and other applications. In radio communication , used in radio and television broadcasting , cell phones, two-way radios , wireless networking , and satellite communication , among numerous other uses, radio waves are used to carry information across space from

1170-474: A " push to talk " button on their radio which switches off the receiver and switches on the transmitter. Or the radio link may be full duplex , a bidirectional link using two radio channels so both people can talk at the same time, as in a cell phone. One way, unidirectional radio transmission is called simplex . This is radio communication between a spacecraft and an Earth-based ground station, or another spacecraft. Communication with spacecraft involves

1300-400: A "hill and dale" vertically modulated groove, rather than the "lateral" side-to-side modulation found on the records being made for home use at that time. The large slow-speed discs could easily contain fifteen minutes on each side, allowing an hour-long program to be recorded on only two discs. The lacquer was softer than shellac or vinyl and wore more rapidly, allowing only a few playbacks with

1430-627: A Service Regulation specifying that "Radiotelegrams shall show in the preamble that the service is 'Radio ' ". The switch to radio in place of wireless took place slowly and unevenly in the English-speaking world. Lee de Forest helped popularize the new word in the United States—in early 1907, he founded the DeForest Radio Telephone Company, and his letter in the 22 June 1907 Electrical World about

SECTION 10

#1732787045099

1560-412: A controller device control the actions of a remote device. The existence of radio waves was first proven by German physicist Heinrich Hertz on 11 November 1886. In the mid-1890s, building on techniques physicists were using to study electromagnetic waves, Italian physicist Guglielmo Marconi developed the first apparatus for long-distance radio communication, sending a wireless Morse Code message to

1690-410: A daytime serial drama by scholars of the genre is Painted Dreams , which premiered on WGN on October 20, 1930. The first networked daytime serial is Clara, Lu, 'n Em , which started in a daytime time slot on February 15, 1932. As daytime serials became popular in the early 1930s, they became known as soap operas because many were sponsored by soap products and detergents. On November 25, 1960,

1820-421: A given bandwidth than analog modulation , by using data compression algorithms, which reduce redundancy in the data to be sent, and more efficient modulation. Other reasons for the transition is that digital modulation has greater noise immunity than analog, digital signal processing chips have more power and flexibility than analog circuits, and a wide variety of types of information can be transmitted using

1950-465: A good wire recording was comparable to acetate discs and by comparison the wire was practically indestructible, but it was soon rendered obsolete by the more manageable and easily edited medium of magnetic tape. Radio Radio is the technology of communicating using radio waves . Radio waves are electromagnetic waves of frequency between 3  hertz (Hz) and 300  gigahertz (GHz). They are generated by an electronic device called

2080-548: A government license, such as the general radiotelephone operator license in the US, obtained by taking a test demonstrating adequate technical and legal knowledge of safe radio operation. Exceptions to the above rules allow the unlicensed operation by the public of low power short-range transmitters in consumer products such as cell phones, cordless phones , wireless devices , walkie-talkies , citizens band radios , wireless microphones , garage door openers , and baby monitors . In

2210-497: A group headed by RCA , which used the assets to form the National Broadcasting Company . Four radio networks had formed by 1934. These were: In the period before and after the advent of the broadcast network, new forms of entertainment needed to be created to fill the time of a station's broadcast day. Many of the formats born in this era continued into the television and digital eras. In the beginning of

2340-455: A guest, had his own program in 1934.) The New York Philharmonic also had weekly concerts on radio. There was no dedicated classical music radio station like NPR at that time, so classical music programs had to share the network they were broadcast on with more popular ones, much as in the days of television before the creation of NET and PBS . Country music also enjoyed popularity. National Barn Dance , begun on Chicago's WLS in 1924,

2470-416: A high-quality radio's audio output was recorded directly, rather than by holding a microphone up to its speaker, the recorded sound quality was very good. However, because the wire cost money and, like magnetic tape , could be repeatedly re-used to make new recordings, only a few complete broadcasts appear to have survived on this medium. In fact, there was little home recording of complete radio programs until

2600-504: A home could now easily listen to their radio at the same time. In 1930, 40% of the nation's households owned a radio, a figure that was much higher in suburban and large metropolitan areas. The superheterodyne receiver and other inventions refined radios even further in the next decade; even as the Great Depression ravaged the country in the 1930s, radio would stay at the center of American life. 83% of American homes would own

2730-587: A large economic cost, but it can also be life-threatening (for example, in the case of interference with emergency communications or air traffic control ). To prevent interference between different users, the emission of radio waves is strictly regulated by national laws, coordinated by an international body, the International Telecommunication Union (ITU), which allocates bands in the radio spectrum for different uses. Radio transmitters must be licensed by governments, under

SECTION 20

#1732787045099

2860-460: A major assault when NBC carried The Goon Show in the mid-1950s. Some shows originated as stage productions: Clifford Goldsmith's play What a Life was reworked into NBC's popular, long-running The Aldrich Family (1939–1953) with the familiar catchphrases "Henry! Henry Aldrich!," followed by Henry's answer, "Coming, Mother!" Moss Hart and George S. Kaufman's Pulitzer Prize-winning Broadway hit, You Can't Take It with You (1936), became

2990-595: A metal conductor called an antenna . As they travel farther from the transmitting antenna, radio waves spread out so their signal strength ( intensity in watts per square meter) decreases (see Inverse-square law ), so radio transmissions can only be received within a limited range of the transmitter, the distance depending on the transmitter power, the antenna radiation pattern , receiver sensitivity, background noise level, and presence of obstructions between transmitter and receiver . An omnidirectional antenna transmits or receives radio waves in all directions, while

3120-427: A more limited information-carrying capacity and so work best with audio signals (speech and music), and the sound quality can be degraded by radio noise from natural and artificial sources. The shortwave bands have a greater potential range but are more subject to interference by distant stations and varying atmospheric conditions that affect reception. In the very high frequency band, greater than 30 megahertz,

3250-436: A network of telephone lines. The development of radio eliminated the wires and subscription charges from this concept. Between 1900 and 1920 the first technology for transmitting sound by radio was developed, AM ( amplitude modulation ), and AM broadcasting sprang up around 1920. On Christmas Eve 1906, Reginald Fessenden is said to have broadcast the first radio program, consisting of some violin playing and passages from

3380-470: A primitive spark-gap transmitter . Experiments by Hertz and physicists Jagadish Chandra Bose , Oliver Lodge , Lord Rayleigh , and Augusto Righi , among others, showed that radio waves like light demonstrated reflection, refraction , diffraction , polarization , standing waves , and traveled at the same speed as light, confirming that both light and radio waves were electromagnetic waves, differing only in frequency. In 1895, Guglielmo Marconi developed

3510-420: A public audience. Analog audio is the earliest form of radio broadcast. AM broadcasting began around 1920. FM broadcasting was introduced in the late 1930s with improved fidelity . A broadcast radio receiver is called a radio . Most radios can receive both AM and FM. Television broadcasting is the transmission of moving images by radio, which consist of sequences of still images, which are displayed on

3640-461: A radio by 1940. Although radio was well established with United States consumers by the mid-1920s, regulation of the broadcast medium presented its own challenges. Until 1926, broadcast radio power and frequency use was regulated by the U.S. Department of Commerce, until a legal challenge rendered the agency powerless to do so. Congress responded by enacting the Radio Act of 1927 , which included

3770-459: A radio signal is usually concentrated in narrow frequency bands called sidebands ( SB ) just above and below the carrier frequency. The width in hertz of the frequency range that the radio signal occupies, the highest frequency minus the lowest frequency, is called its bandwidth ( BW ). For any given signal-to-noise ratio , an amount of bandwidth can carry the same amount of information ( data rate in bits per second) regardless of where in

3900-489: A receiver that is typically colocated with the transmitter. In radio navigation systems such as GPS and VOR , a mobile navigation instrument receives radio signals from multiple navigational radio beacons whose position is known, and by precisely measuring the arrival time of the radio waves the receiver can calculate its position on Earth. In wireless radio remote control devices like drones , garage door openers , and keyless entry systems , radio signals transmitted from

4030-533: A recipient over a kilometer away in 1895, and the first transatlantic signal on 12 December 1901. The first commercial radio broadcast was transmitted on 2 November 1920, when the live returns of the Harding-Cox presidential election were broadcast by Westinghouse Electric and Manufacturing Company in Pittsburgh, under the call sign KDKA . The emission of radio waves is regulated by law, coordinated by

Spinoff (media) - Misplaced Pages Continue

4160-673: A reference to the radiotelegraph and radiotelegraphy . The use of radio as a standalone word dates back to at least 30 December 1904, when instructions issued by the British Post Office for transmitting telegrams specified that "The word 'Radio'... is sent in the Service Instructions." This practice was universally adopted, and the word "radio" introduced internationally, by the 1906 Berlin Radiotelegraphic Convention, which included

4290-446: A screen on a television receiver (a "television" or TV) along with a synchronized audio (sound) channel. Television ( video ) signals occupy a wider bandwidth than broadcast radio ( audio ) signals. Analog television , the original television technology, required 6 MHz, so the television frequency bands are divided into 6 MHz channels, now called "RF channels". The current television standard, introduced beginning in 2006,

4420-879: A series of one-hour adaptations of Shakespeare plays, many of which Barrymore never appeared in either on stage or in films, such as Twelfth Night (in which he played both Malvolio and Sir Toby Belch ), and Macbeth . Lux Radio Theatre and The Screen Guild Theater presented adaptations of Hollywood movies, performed before a live audience, usually with cast members from the original films. Suspense , Escape , The Mysterious Traveler and Inner Sanctum Mystery were popular thriller anthology series. Leading writers who created original material for radio included Norman Corwin , Carlton E. Morse , David Goodis , Archibald MacLeish , Arthur Miller , Arch Oboler , Wyllis Cooper , Rod Serling , Jay Bennett , and Irwin Shaw . Game shows saw their beginnings in radio. One of

4550-447: A service designed to sell radio receivers. In early 1922, American Telephone & Telegraph Company (AT&T) announced the beginning of advertisement-supported broadcasting on its owned stations, and plans for the development of the first radio network using its telephone lines to transmit the content. In July 1926, AT&T abruptly decided to exit the broadcasting field, and signed an agreement to sell its entire network operations to

4680-496: A show is not a spin-off of another, there will nevertheless be crossovers in which a character from one show makes an appearance on another. Sometimes crossovers are created in an attempt to provide closure to fans of another failed series. Sometimes show producers will re-introduce a character from an older series into a later one as a way of providing a connectivity of that particular producer's television "world". Golden Age of Radio The Golden Age of Radio , also known as

4810-441: A smaller bandwidth than the old analog channels, saving scarce radio spectrum space. Therefore, each of the 6 MHz analog RF channels now carries up to 7 DTV channels – these are called "virtual channels". Digital television receivers have different behavior in the presence of poor reception or noise than analog television, called the " digital cliff " effect. Unlike analog television, in which increasingly poor reception causes

4940-489: A sponsor's product. These items were offered on adventure shows. Young listeners had to mail in a boxtop from a breakfast cereal or other proof of purchase . Radio plays were presented on such programs as 26 by Corwin , NBC Short Story , Arch Oboler's Plays , Quiet, Please , and CBS Radio Workshop . Orson Welles 's The Mercury Theatre on the Air and The Campbell Playhouse were considered by many critics to be

5070-459: A substantial number of copies of an electrical transcription were required, as for the distribution of a syndicated program, they were produced by the same process used to make ordinary records. A master recording was cut, then electroplated to produce a stamper from which pressings in vinyl (or, in the case of transcription discs pressed before about 1935, shellac) were molded in a record press. The Armed Forces Radio Service (AFRS) had its origins in

5200-416: A television (video) signal has a greater data rate than an audio signal . The radio spectrum , the total range of radio frequencies that can be used for communication in a given area, is a limited resource. Each radio transmission occupies a portion of the total bandwidth available. Radio bandwidth is regarded as an economic good which has a monetary cost and is in increasing demand. In some parts of

5330-400: A transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track objects like aircraft, ships, spacecraft and missiles, a beam of radio waves emitted by a radar transmitter reflects off the target object, and the reflected waves reveal the object's location to

Spinoff (media) - Misplaced Pages Continue

5460-652: A transmitter to control the actions of a device at a remote location. Remote control systems may also include telemetry channels in the other direction, used to transmit real-time information on the state of the device back to the control station. Uncrewed spacecraft are an example of remote-controlled machines, controlled by commands transmitted by satellite ground stations . Most handheld remote controls used to control consumer electronics products like televisions or DVD players actually operate by infrared light rather than radio waves, so are not examples of radio remote control. A security concern with remote control systems

5590-435: A variety of license classes depending on use, and are restricted to certain frequencies and power levels. In some classes, such as radio and television broadcasting stations, the transmitter is given a unique identifier consisting of a string of letters and numbers called a call sign , which must be used in all transmissions. In order to adjust, maintain, or internally repair radiotelephone transmitters, individuals must hold

5720-608: A weekly situation comedy heard on Mutual (1944) with Everett Sloane and later on NBC (1951) with Walter Brennan . Other shows were adapted from comic strips, such as Blondie , Dick Tracy , Gasoline Alley , The Gumps , Li'l Abner , Little Orphan Annie , Popeye the Sailor , Red Ryder , Reg'lar Fellers , Terry and the Pirates and Tillie the Toiler . Bob Montana's redheaded teen of comic strips and comic books

5850-413: Is amplified in the transmitter and applied to a transmitting antenna which radiates the energy as radio waves. The radio waves carry the information to the receiver location. At the receiver, the radio wave induces a tiny oscillating voltage in the receiving antenna which is a weaker replica of the current in the transmitting antenna. This voltage is applied to the radio receiver , which amplifies

5980-703: Is spoofing , in which an unauthorized person transmits an imitation of the control signal to take control of the device. Examples of radio remote control: Radio jamming is the deliberate radiation of radio signals designed to interfere with the reception of other radio signals. Jamming devices are called "signal suppressors" or "interference generators" or just jammers. During wartime, militaries use jamming to interfere with enemies' tactical radio communication. Since radio waves can pass beyond national borders, some totalitarian countries which practice censorship use jamming to prevent their citizens from listening to broadcasts from radio stations in other countries. Jamming

6110-445: Is a digital format called high-definition television (HDTV), which transmits pictures at higher resolution, typically 1080 pixels high by 1920 pixels wide, at a rate of 25 or 30 frames per second. Digital television (DTV) transmission systems, which replaced older analog television in a transition beginning in 2006, use image compression and high-efficiency digital modulation such as OFDM and 8VSB to transmit HDTV video within

6240-433: Is an audio transceiver , a receiver and transmitter in the same device, used for bidirectional person-to-person voice communication with other users with similar radios. An older term for this mode of communication is radiotelephony . The radio link may be half-duplex , as in a walkie-talkie , using a single radio channel in which only one radio can transmit at a time, so different users take turns talking, pressing

6370-410: Is called "tuning". The oscillating radio signal from the desired station causes the tuned circuit to resonate , oscillate in sympathy, and it passes the signal on to the rest of the receiver. Radio signals at other frequencies are blocked by the tuned circuit and not passed on. A modulated radio wave, carrying an information signal, occupies a range of frequencies . The information ( modulation ) in

6500-427: Is called an uplink , while a link that transmits data from the spacecraft to the ground is called a downlink. Radar is a radiolocation method used to locate and track aircraft, spacecraft, missiles, ships, vehicles, and also to map weather patterns and terrain. A radar set consists of a transmitter and receiver. The transmitter emits a narrow beam of radio waves which is swept around the surrounding space. When

6630-565: Is in radio clocks and watches, which include an automated receiver that periodically (usually weekly) receives and decodes the time signal and resets the watch's internal quartz clock to the correct time, thus allowing a small watch or desk clock to have the same accuracy as an atomic clock. Government time stations are declining in number because GPS satellites and the Internet Network Time Protocol (NTP) provide equally accurate time standards. A two-way radio

SECTION 50

#1732787045099

6760-417: Is mainly due to their desirable propagation properties stemming from their longer wavelength. In radio communication systems, information is carried across space using radio waves. At the sending end, the information to be sent is converted by some type of transducer to a time-varying electrical signal called the modulation signal. The modulation signal may be an audio signal representing sound from

6890-524: Is the one-way transmission of information from a transmitter to receivers belonging to a public audience. Since the radio waves become weaker with distance, a broadcasting station can only be received within a limited distance of its transmitter. Systems that broadcast from satellites can generally be received over an entire country or continent. Older terrestrial radio and television are paid for by commercial advertising or governments. In subscription systems like satellite television and satellite radio

7020-484: Is the only surviving recording of a program. There was some home recording of radio broadcasts in the 1930s and 1940s. Examples from as early as 1930 have been documented. During these years, home recordings were made with disc recorders, most of which were only capable of storing about four minutes of a radio program on each side of a twelve-inch 78 rpm record. Most home recordings were made on even shorter-playing ten-inch or smaller discs. Some home disc recorders offered

7150-611: The Columbia Broadcasting System in support of America's cultural diplomacy initiatives and President Franklin Roosevelt's Good Neighbor policy . Included among the popular shows was Viva America which showcased leading musical artists from both North and South America for the entertainment of America's troops. Included among the regular performers were: Alfredo Antonini , Juan Arvizu , Nestor Mesta Chayres , Kate Smith , and John Serry Sr. After

7280-595: The International Telecommunication Union (ITU), which allocates frequency bands in the radio spectrum for various uses. The word radio is derived from the Latin word radius , meaning "spoke of a wheel, beam of light, ray". It was first applied to communications in 1881 when, at the suggestion of French scientist Ernest Mercadier  [ fr ] , Alexander Graham Bell adopted radiophone (meaning "radiated sound") as an alternate name for his photophone optical transmission system. Following Hertz's discovery of

7410-504: The ionosphere without refraction , and at microwave frequencies the high-gain antennas needed to focus the radio energy into a narrow beam pointed at the receiver are small and take up a minimum of space in a satellite. Portions of the UHF , L , C , S , k u and k a band are allocated for space communication. A radio link that transmits data from the Earth's surface to a spacecraft

7540-597: The old-time radio ( OTR ) era, was an era of radio in the United States where it was the dominant electronic home entertainment medium . It began with the birth of commercial radio broadcasting in the early 1920s and lasted through the 1950s, when television gradually superseded radio as the medium of choice for scripted programming, variety and dramatic shows. Radio was the first broadcast medium , and during this period people regularly tuned in to their favorite radio programs, and families gathered to listen to

7670-400: The radio spectrum into 12 bands, each beginning at a wavelength which is a power of ten (10 ) metres, with corresponding frequency of 3 times a power of ten, and each covering a decade of frequency or wavelength. Each of these bands has a traditional name: It can be seen that the bandwidth , the range of frequencies, contained in each band is not equal but increases exponentially as

7800-531: The 1920s with the introduction of broadcasting. Electromagnetic waves were predicted by James Clerk Maxwell in his 1873 theory of electromagnetism , now called Maxwell's equations , who proposed that a coupled oscillating electric field and magnetic field could travel through space as a wave, and proposed that light consisted of electromagnetic waves of short wavelength . On 11 November 1886, German physicist Heinrich Hertz , attempting to confirm Maxwell's theory, first observed radio waves he generated using

7930-450: The 1940s, Basil Rathbone and Nigel Bruce , famous for playing Sherlock Holmes and Dr. Watson in films, repeated their characterizations on radio on The New Adventures of Sherlock Holmes , which featured both original stories and episodes directly adapted from Arthur Conan Doyle 's stories. None of the episodes in which Rathbone and Bruce starred on the radio program were filmed with the two actors as Holmes and Watson, so radio became

SECTION 60

#1732787045099

8060-411: The 1950s, television surpassed radio as the most popular broadcast medium, and commercial radio programming shifted to narrower formats of news, talk, sports and music. Religious broadcasters, listener-supported public radio and college stations provide their own distinctive formats. During the first three decades of radio , from 1887 to about 1920, the technology of transmitting sound was undeveloped;

8190-510: The AFRS during the Golden Age were recorded as electrical transcription discs, vinyl copies of which were shipped to stations overseas to be broadcast to the troops. People in the United States rarely ever heard programming from the AFRS, though AFRS recordings of Golden Age network shows were occasionally broadcast on some domestic stations beginning in the 1950s. In some cases, the AFRS disc

8320-558: The Bible. While Fessenden's role as an inventor and early radio experimenter is not in dispute, several contemporary radio researchers have questioned whether the Christmas Eve broadcast took place, or whether the date was, in fact, several weeks earlier. The first apparent published reference to the event was made in 1928 by H. P. Davis, Vice President of Westinghouse , in a lecture given at Harvard University . In 1932 Fessenden cited

8450-662: The Christmas Eve 1906 broadcast event in a letter he wrote to Vice President S. M. Kinter of Westinghouse. Fessenden's wife Helen recounts the broadcast in her book Fessenden: Builder of Tomorrows (1940), eight years after Fessenden's death. The issue of whether the 1906 Fessenden broadcast actually happened is discussed in Donna Halper's article "In Search of the Truth About Fessenden" and also in James O'Neal's essays. An annotated argument supporting Fessenden as

8580-474: The Earth's atmosphere has less of an effect on the range of signals, and line-of-sight propagation becomes the principal mode. These higher frequencies permit the great bandwidth required for television broadcasting. Since natural and artificial noise sources are less present at these frequencies, high-quality audio transmission is possible, using frequency modulation . Radio broadcasting means transmission of audio (sound) to radio receivers belonging to

8710-467: The Golden Age, network programs were almost exclusively broadcast live, as the national networks prohibited the airing of recorded programs until the late 1940s because of the inferior sound quality of phonograph discs, the only practical recording medium at that time. As a result, network prime-time shows would be performed twice, once for each coast. Coverage of live events included musical concerts and play-by-play sports broadcasts. The capability of

8840-470: The U.S. War Department 's quest to improve troop morale. This quest began with short-wave broadcasts of educational and information programs to troops in 1940. In 1941, the War Department began issuing "Buddy Kits" (B-Kits) to departing troops, which consisted of radios, 78 rpm records and electrical transcription discs of radio shows. However, with the entrance of the United States into World War II,

8970-596: The US, these fall under Part 15 of the Federal Communications Commission (FCC) regulations. Many of these devices use the ISM bands , a series of frequency bands throughout the radio spectrum reserved for unlicensed use. Although they can be operated without a license, like all radio equipment these devices generally must be type-approved before the sale. Below are some of the most important uses of radio, organized by function. Broadcasting

9100-479: The War Department decided that it needed to improve the quality and quantity of its offerings. This began with the broadcasting of its own original variety programs. Command Performance was the first of these, produced for the first time on March 1, 1942. On May 26, 1942, the Armed Forces Radio Service was formally established. Originally, its programming comprised network radio shows with

9230-405: The air simultaneously without interfering with each other because each transmitter's radio waves oscillate at a different rate, in other words, each transmitter has a different frequency , measured in hertz (Hz), kilohertz (kHz), megahertz (MHz) or gigahertz (GHz). The receiving antenna typically picks up the radio signals of many transmitters. The receiver uses tuned circuits to select

9360-414: The beam strikes a target object, radio waves are reflected back to the receiver. The direction of the beam reveals the object's location. Since radio waves travel at a constant speed close to the speed of light , by measuring the brief time delay between the outgoing pulse and the received "echo", the range to the target can be calculated. The targets are often displayed graphically on a map display called

9490-409: The blanks varied in both size and composition, but most often they were simply bare aluminum and the groove was indented rather than cut. Typically, these very early recordings were not made by the network or radio station, but by a private recording service contracted by the broadcast sponsor or one of the performers. The bare aluminum discs were typically 10 or 12 inches in diameter and recorded at

9620-408: The carpeted floor after use. Despite a general ban on use of recordings on broadcasts by radio networks through the late 1940s, "reference recordings" on phonograph disc were made of many programs as they were being broadcast, for review by the sponsor and for the network's own archival purposes. With the development of high-fidelity magnetic wire and tape recording in the years following World War II,

9750-570: The commercials removed. However, it soon began producing original programming, such as Mail Call , G.I. Journal , Jubilee and GI Jive . At its peak in 1945, the Service produced around 20 hours of original programming each week. From 1943 until 1949 the AFRS also broadcast programs developed through the collaborative efforts of the Office of the Coordinator of Inter-American Affairs and

9880-668: The continuous waves which were needed for audio modulation , so radio was used for person-to-person commercial, diplomatic and military text messaging. Starting around 1908 industrial countries built worldwide networks of powerful transoceanic transmitters to exchange telegram traffic between continents and communicate with their colonies and naval fleets. During World War I the development of continuous wave radio transmitters, rectifying electrolytic, and crystal radio receiver detectors enabled amplitude modulation (AM) radiotelephony to be achieved by Reginald Fessenden and others, allowing audio to be transmitted. On 2 November 1920,

10010-417: The country's stations were assigned to new transmitting frequencies. The final element needed to make the Golden Age of Radio possible focused on the question of distribution: the ability for multiple radio stations to simultaneously broadcast the same content, and this would be solved with the concept of a radio network . The earliest radio programs of the 1920s were largely unsponsored; radio stations were

10140-466: The customer pays a monthly fee. In these systems, the radio signal is encrypted and can only be decrypted by the receiver, which is controlled by the company and can be deactivated if the customer does not pay. Broadcasting uses several parts of the radio spectrum, depending on the type of signals transmitted and the desired target audience. Longwave and medium wave signals can give reliable coverage of areas several hundred kilometers across, but have

10270-411: The decade of the 1920s, the purchase of radios by United States homes continued, and accelerated. The Radio Corporation of America (RCA) released figures in 1925 stating that 19% of United States homes owned a radio. The triode and regenerative circuit made amplified, vacuum tube radios widely available to consumers by the second half of the 1920s. The advantage was obvious: several people at once in

10400-399: The disc change-over points would match and result in a more seamless playback. An inside start also had the advantage that the thread of material cut from the disc's surface, which had to be kept out of the path of the cutting stylus, was naturally thrown toward the center of the disc so was automatically out of the way. When cutting an outside start disc, a brush could be used to keep it out of

10530-425: The duration of the war. In the late 1940s, wire recorders became a readily obtainable means of recording radio programs. On a per-minute basis, it was less expensive to record a broadcast on wire than on discs. The one-hour program that required the four sides of two 16-inch discs could be recorded intact on a single spool of wire less than three inches in diameter and about half an inch thick. The audio fidelity of

10660-410: The early 1950s, when increasingly affordable reel-to-reel tape recorders for home use were introduced to the market. Before the early 1950s, when radio networks and local stations wanted to preserve a live broadcast, they did so by means of special phonograph records known as " electrical transcriptions " (ETs), made by cutting a sound-modulated groove into a blank disc. At first, in the early 1930s,

10790-570: The existence of radio waves in 1886, the term Hertzian waves was initially used for this radiation. The first practical radio communication systems, developed by Marconi in 1894–1895, transmitted telegraph signals by radio waves, so radio communication was first called wireless telegraphy . Up until about 1910 the term wireless telegraphy also included a variety of other experimental systems for transmitting telegraph signals without wires, including electrostatic induction , electromagnetic induction and aquatic and earth conduction , so there

10920-419: The expense of recorders and the limitations of the recording media, home recording of broadcasts was not common during this period and it was usually limited to brief excerpts. The lack of suitable home recording equipment was somewhat relieved in 1947 with the availability of magnetic wire recorders for domestic use. These were capable of recording an hour-long broadcast on a single small spool of wire, and if

11050-606: The few examples of live classical music still broadcast on radio. One of the most notable of all classical music radio programs of the Golden Age of Radio featured the celebrated Italian conductor Arturo Toscanini conducting the NBC Symphony Orchestra , which had been created especially for him. At that time, nearly all classical musicians and critics considered Toscanini the greatest living maestro. Popular songwriters such as George Gershwin were also featured on radio. (Gershwin, in addition to frequent appearances as

11180-403: The finest radio drama anthologies ever presented. They usually starred Welles in the leading role, along with celebrity guest stars such as Margaret Sullavan or Helen Hayes , in adaptations from literature, Broadway, and/or films. They included such titles as Liliom , Oliver Twist (a title now feared lost), A Tale of Two Cities , Lost Horizon , and The Murder of Roger Ackroyd . It

11310-413: The first commercial radio broadcast was transmitted by Westinghouse Electric and Manufacturing Company in Pittsburgh, under the call sign KDKA featuring live coverage of the Harding-Cox presidential election . Radio waves are radiated by electric charges undergoing acceleration . They are generated artificially by time-varying electric currents , consisting of electrons flowing back and forth in

11440-592: The first radio communication system, using a spark-gap transmitter to send Morse code over long distances. By December 1901, he had transmitted across the Atlantic Ocean. Marconi and Karl Ferdinand Braun shared the 1909 Nobel Prize in Physics "for their contributions to the development of wireless telegraphy". During radio's first two decades, called the radiotelegraphy era, the primitive radio transmitters could only transmit pulses of radio waves, not

11570-467: The first was Information Please in 1938, and one of the first major successes was Dr. I.Q. in 1939. Winner Take All , which premiered in 1946, was the first to use lockout devices and feature returning champions. A relative of the game show, which would be called the giveaway show in contemporary media, typically involved giving sponsored products to studio audience members, people randomly called by telephone, or both. An early example of this show

11700-572: The formation of the Federal Radio Commission (FRC). One of the FRC's most important early actions was the adoption of General Order 40 , which divided stations on the AM band into three power level categories, which became known as Local, Regional, and Clear Channel, and reorganized station assignments. Based on this plan, effective 3:00 a.m. Eastern time on November 11, 1928, most of

11830-618: The frequency increases; each band contains ten times the bandwidth of the preceding band. The term "tremendously low frequency" (TLF) has been used for wavelengths from 1–3 Hz (300,000–100,000 km), though the term has not been defined by the ITU. The airwaves are a resource shared by many users. Two radio transmitters in the same area that attempt to transmit on the same frequency will interfere with each other, causing garbled reception, so neither transmission may be received clearly. Interference with radio transmissions can not only have

11960-570: The gamut from the small town humor of Lum and Abner , Herb Shriner and Minnie Pearl to the dialect characterizations of Mel Blanc and the caustic sarcasm of Henry Morgan . Gags galore were delivered weekly on Stop Me If You've Heard This One and Can You Top This? , panel programs devoted to the art of telling jokes. Quiz shows were lampooned on It Pays to Be Ignorant , and other memorable parodies were presented by such satirists as Spike Jones , Stoopnagle and Budd , Stan Freberg and Bob and Ray . British comedy reached American shores in

12090-542: The heavy pickups and steel needles then in use before deterioration became audible. During World War II, aluminum became a necessary material for the war effort and was in short supply. This caused an alternative to be sought for the base on which to coat the lacquer. Glass, despite its obvious disadvantage of fragility, had occasionally been used in earlier years because it could provide a perfectly smooth and even supporting surface for mastering and other critical applications. Glass base recording blanks came into general use for

12220-473: The home radio in the evening. According to a 1947 C. E. Hooper survey, 82 out of 100 Americans were found to be radio listeners. A variety of new entertainment formats and genres were created for the new medium, many of which later migrated to television: radio plays , mystery serials, soap operas , quiz shows , talent shows , daytime and evening variety hours , situation comedies , play-by-play sports, children's shows , cooking shows , and more. In

12350-542: The information-carrying ability of radio waves was the same as a telegraph ; the radio signal could be either on or off. Radio communication was by wireless telegraphy ; at the sending end, an operator tapped on a switch which caused the radio transmitter to produce a series of pulses of radio waves which spelled out text messages in Morse code . At the receiver these sounded like beeps, requiring an operator who knew Morse code to translate them back to text. This type of radio

12480-752: The last four daytime radio dramas— Young Dr. Malone , Right to Happiness , The Second Mrs. Burton and Ma Perkins , all broadcast on the CBS Radio Network —were brought to an end. The line-up of late afternoon adventure serials included Bobby Benson and the B-Bar-B Riders , The Cisco Kid , Jack Armstrong, the All-American Boy , Captain Midnight , and The Tom Mix Ralston Straight Shooters . Badges, rings, decoding devices and other radio premiums were often linked to

12610-529: The late 1920s and early 1930s. Local stations often had staff organists such as Jesse Crawford playing popular tunes. Classical music programs on the air included The Voice of Firestone and The Bell Telephone Hour . Texaco sponsored the Metropolitan Opera radio broadcasts ; the broadcasts, now sponsored by the Toll Brothers , continue to this day around the world, and are one of

12740-404: The least as a historical mention, in the new subseries. Spin-offs sometimes generate their own spin-offs, leaving the new show in its own series only vaguely connected to the original series - for example, the police procedural franchises of NCIS / JAG and CSI have both spun multiple shows, including multiple spin-offs from series and spin-offs from spin-offs. A spin-off may be called

12870-402: The longest transmission distances of any radio links, up to billions of kilometers for interplanetary spacecraft . In order to receive the weak signals from distant spacecraft, satellite ground stations use large parabolic "dish" antennas up to 25 metres (82 ft) in diameter and extremely sensitive receivers. High frequencies in the microwave band are used, since microwaves pass through

13000-411: The modern era, were still relatively uncommon and considered intrusive. During the 1930s and 1940s, the leading orchestras were heard often through big band remotes , and NBC's Monitor continued such remotes well into the 1950s by broadcasting live music from New York City jazz clubs to rural America. Singers such as Harriet Lee and Wendell Hall became popular fixtures on network radio beginning in

13130-472: The need for legal restrictions warned that "Radio chaos will certainly be the result until such stringent regulation is enforced." The United States Navy would also play a role. Although its translation of the 1906 Berlin Convention used the terms wireless telegraph and wireless telegram , by 1912 it began to promote the use of radio instead. The term started to become preferred by the general public in

13260-472: The networks became more open to airing recorded programs and the prerecording of shows became more common. Local stations, however, had always been free to use recordings and sometimes made substantial use of prerecorded syndicated programs distributed on pressed (as opposed to individually recorded) transcription discs . Recording was done using a cutting lathe and acetate discs . Programs were normally recorded at 33 1 ⁄ 3 rpm on 16-inch discs,

13390-414: The new medium to get information to people created the format of modern radio news : headlines, remote reporting , sidewalk interviews (such as Vox Pop ), panel discussions , weather reports , and farm reports. The entry of radio into the realm of news triggered a feud between the radio and newspaper industries in the mid-1930s , eventually culminating in newspapers trumping up exaggerated reports of

13520-412: The only medium in which audiences were able to experience Rathbone and Bruce appearing in some of the more famous Holmes stories, such as " The Speckled Band ". There were also many dramatizations of Sherlock Holmes stories on radio without Rathbone and Bruce. During the latter part of his career, celebrated actor John Barrymore starred in a radio program, Streamlined Shakespeare , which featured him in

13650-436: The option of the 33 1 ⁄ 3 rpm speed used for electrical transcriptions, allowing a recording more than twice as long to be made, although with reduced audio quality. Office dictation equipment was sometimes pressed into service for making recordings of radio broadcasts, but the audio quality of these devices was poor and the resulting recordings were in odd formats that had to be played back on similar equipment. Due to

13780-400: The original work (e.g. particular topics, characters or events), and includes books, radio programs , television programs , films, video games , or any narrative work in any medium. In genre fiction , the term parallels its usage in television; it is usually meant to indicate a substantial change in narrative viewpoint and activity from that (previous) storyline based on the activities of

13910-505: The picture quality to gradually degrade, in digital television picture quality is not affected by poor reception until, at a certain point, the receiver stops working and the screen goes black. Government standard frequency and time signal services operate time radio stations which continuously broadcast extremely accurate time signals produced by atomic clocks , as a reference to synchronize other clocks. Examples are BPC , DCF77 , JJY , MSF , RTZ , TDF , WWV , and YVTO . One use

14040-451: The radio frequency spectrum it is located, so bandwidth is a measure of information-carrying capacity . The bandwidth required by a radio transmission depends on the data rate of the information (modulation signal) being sent, and the spectral efficiency of the modulation method used; how much data it can transmit in each kilohertz of bandwidth. Different types of information signals carried by radio have different data rates. For example,

14170-409: The radio signal desired out of all the signals picked up by the antenna and reject the others. A tuned circuit (also called resonant circuit or tank circuit) acts like a resonator , similar to a tuning fork . It has a natural resonant frequency at which it oscillates. The resonant frequency of the receiver's tuned circuit is adjusted by the user to the frequency of the desired radio station; this

14300-451: The radio spectrum, the right to use a frequency band or even a single radio channel is bought and sold for millions of dollars. So there is an incentive to employ technology to minimize the bandwidth used by radio services. A slow transition from analog to digital radio transmission technologies began in the late 1990s. Part of the reason for this is that digital modulation can often transmit more information (a greater data rate) in

14430-456: The radio waves that carry the information through the air. The modulation signal is used to modulate the carrier, varying some aspect of the carrier wave, impressing the information in the modulation signal onto the carrier. Different radio systems use different modulation methods: Many other types of modulation are also used. In some types, a carrier wave is not transmitted but just one or both modulation sidebands . The modulated carrier

14560-481: The same digital modulation. Because it is a fixed resource which is in demand by an increasing number of users, the radio spectrum has become increasingly congested in recent decades, and the need to use it more effectively is driving many additional radio innovations such as trunked radio systems , spread spectrum (ultra-wideband) transmission, frequency reuse , dynamic spectrum management , frequency pooling, and cognitive radio . The ITU arbitrarily divides

14690-419: The series' principal protagonist, and so is a shift to that action and overall narrative thread of some other protagonist, which now becomes the central or main thread (storyline) of the new subseries. The new protagonist generally appears first as a minor or supporting character in the main storyline within a given milieu and it is very common for the previous protagonist to have a supporting or cameo role, at

14820-403: The standard format used for such " electrical transcriptions " from the early 1930s through the 1950s. Sometimes, the groove was cut starting at the inside of the disc and running to the outside. This was useful when the program to be recorded was longer than 15 minutes so required more than one disc side. By recording the first side outside in, the second inside out, and so on, the sound quality at

14950-513: The then-standard speed of 78 rpm , which meant that several disc sides were required to accommodate even a 15-minute program. By about 1936, 16-inch aluminum-based discs coated with cellulose nitrate lacquer, commonly known as acetates and recorded at a speed of 33 1 ⁄ 3 rpm, had been adopted by the networks and individual radio stations as the standard medium for recording broadcasts. The making of such recordings, at least for some purposes, then became routine. Some discs were recorded using

15080-431: The transmitting antenna also serves as the receiving antenna; this is called a monostatic radar . A radar which uses separate transmitting and receiving antennas is called a bistatic radar . Radiolocation is a generic term covering a variety of techniques that use radio waves to find the location of objects, or for navigation. Radio remote control is the use of electronic control signals sent by radio waves from

15210-668: The war, the AFRS continued providing programming to troops in Europe. During the 1950s and early 1960s it presented performances by the Army's only symphonic orchestra ensemble—the Seventh Army Symphony Orchestra . It also provided programming for future wars that the United States was involved in. It survives today as a component of the American Forces Network (AFN). All of the shows aired by

15340-417: The way by sweeping it toward the middle of the disc. Well-equipped recording lathes used the vacuum from a water aspirator to pick it up as it was cut and deposit it in a water-filled bottle. In addition to convenience, this served a safety purpose, as the cellulose nitrate thread was highly flammable and a loose accumulation of it combusted violently if ignited. Most recordings of radio broadcasts were made at

15470-510: The weak radio signal so it is stronger, then demodulates it, extracting the original modulation signal from the modulated carrier wave. The modulation signal is converted by a transducer back to a human-usable form: an audio signal is converted to sound waves by a loudspeaker or earphones, a video signal is converted to images by a display , while a digital signal is applied to a computer or microprocessor, which interacts with human users. The radio waves from many transmitters pass through

15600-588: The world's first radio broadcaster was offered in 2006 by Dr. John S. Belrose, Radioscientist Emeritus at the Communications Research Centre Canada, in his essay "Fessenden's 1906 Christmas Eve broadcast." It was not until after the Titanic catastrophe in 1912 that radio for mass communication came into vogue, inspired first by the work of amateur ("ham") radio operators. Radio was especially important during World War I as it

15730-545: Was a need for a more precise term referring exclusively to electromagnetic radiation. The French physicist Édouard Branly , who in 1890 developed the radio wave detecting coherer , called it in French a radio-conducteur . The radio- prefix was later used to form additional descriptive compound and hyphenated words, especially in Europe. For example, in early 1898 the British publication The Practical Engineer included

15860-637: Was broadcast on August 31, 1920, on the station 8MK in Detroit ; owned by The Detroit News , the station covered local election results. This was followed in 1920 with the first commercial radio station in the United States, KDKA , being established in Pittsburgh . The first regular entertainment programs were broadcast in 1922, and on March 10, Variety carried the front-page headline: "Radio Sweeping Country: 1,000,000 Sets in Use." A highlight of this time

15990-546: Was even made by the FCC to ban them (as an illegal lottery) in August 1949. The RCA Type 44-BX microphone had two live faces and two dead ones. Thus actors could face each other and react. An actor could give the effect of leaving the room by simply moving their head toward the dead face of the microphone. The scripts were paper-clipped together. It has been disputed whether or not actors and actresses would drop finished pages to

16120-455: Was heard on radio's Archie Andrews from 1943 to 1953. The Timid Soul was a 1941–1942 comedy based on cartoonist H. T. Webster 's famed Caspar Milquetoast character, and Robert L. Ripley's Believe It or Not! was adapted to several different radio formats during the 1930s and 1940s. Conversely, some radio shows gave rise to spinoff comic strips, such as My Friend Irma starring Marie Wilson . The first program generally considered to be

16250-492: Was on Mercury Theatre that Welles presented his celebrated-but-infamous 1938 adaptation of H. G. Wells 's The War of the Worlds , formatted to sound like a breaking news program. Theatre Guild on the Air presented adaptations of classical and Broadway plays. Their Shakespeare adaptations included a one-hour Macbeth starring Maurice Evans and Judith Anderson , and a 90-minute Hamlet , starring John Gielgud . Recordings of many of these programs survive. During

16380-1120: Was picked up by NBC Radio in 1933. In 1925, WSM Barn Dance went on the air from Nashville . It was renamed the Grand Ole Opry in 1927 and NBC carried portions from 1944 to 1956. NBC also aired The Red Foley Show from 1951 to 1961, and ABC Radio carried Ozark Jubilee from 1953 to 1961. Radio attracted top comedy talents from vaudeville and Hollywood for many years: Bing Crosby , Abbott and Costello , Fred Allen , Jack Benny , Victor Borge , Fanny Brice , Billie Burke , Bob Burns , Judy Canova , Eddie Cantor , Jimmy Durante , Burns and Allen , Phil Harris , Edgar Bergen , Bob Hope , Groucho Marx , Jean Shepherd , Red Skelton and Ed Wynn . Situational comedies also gained popularity, such as Amos 'n' Andy , Easy Aces , Ethel and Albert , Fibber McGee and Molly , The Goldbergs , The Great Gildersleeve , The Halls of Ivy (which featured screen star Ronald Colman and his wife Benita Hume ), Meet Corliss Archer , Meet Millie , and Our Miss Brooks . Radio comedy ran

16510-459: Was the 1939 show Pot o' Gold , but the breakout hit of this type was ABC's Stop the Music in 1948. Winning a prize generally required knowledge of what was being aired on the show at that moment, which led to criticism of the giveaway show as a form of "buying an audience". Giveaway shows were extremely popular through 1948 and 1949. They were often panned as low-brow, and an unsuccessful attempt

16640-489: Was the first Rose Bowl being broadcast on January 1, 1923, on the Los Angeles station KHJ . Broadcast radio in the United States underwent a period of rapid change through the decade of the 1920s. Technology advances, better regulation, rapid consumer adoption, and the creation of broadcast networks transformed radio from a consumer curiosity into the mass media powerhouse that defined the Golden Age of Radio. Through

16770-570: Was used exclusively for person-to-person text communication for commercial, diplomatic and military purposes and hobbyists; broadcasting did not exist. The broadcasts of live drama, comedy, music and news that characterize the Golden Age of Radio had a precedent in the Théâtrophone , commercially introduced in Paris in 1890 and available as late as 1932. It allowed subscribers to eavesdrop on live stage performances and hear news reports by means of

16900-445: Was vital for air and naval operations. World War I brought about major developments in radio, superseding the Morse code of the wireless telegraph with the vocal communication of the wireless telephone, through advancements in vacuum tube technology and the introduction of the transceiver . After the war, numerous radio stations were born in the United States and set the standard for later radio programs. The first radio news program

#98901