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C-QUAM
C-QUAM (Compatible QUadrature Amplitude Modulation) is the method of AM stereo broadcasting used in Canada, the United States and most other countries. It was invented in 1977 by Norman Parker, Francis Hilbert, and Yoshio Sakaie, and published in an IEEE journal. Using circuitry developed by Motorola, C-QUAM uses quadrature amplitude modulation (QAM) to encode the stereo separation signal. This extra signal is then stripped down in such a way that it is compatible with the envelope detector of older receivers, hence the name C-QUAM for Compatible. A 25 Hz pilot tone is added to trigger receivers; unlike its counterpart in FM radio, this carrier is not necessary for the reconstruction of the original audio sources. Description The C-QUAM signal is composed of two distinct modulation stages: a conventional AM version and a compatible quadrature PM version. Stage 1 provides the transmitter with a summed L+R mono audio input. This input is precisely the same as conventional AM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WBLQ (AM)
WBLQ (1230 AM) is a radio station licensed to serve Westerly, Rhode Island. The station is owned by Diponti Communications. History 1940s 1949 The station, then called WERI, began broadcasting on 1230kc. on July 1, 1949, using Day/Night power of 250 watts, non-directional. The station still uses its original 185-foot, Blaw-Knox, self-supporting tower, on Margin Street, beside the Pawcatuck River. 1960s The FCC increases the daytime power of all Class IV AM stations to 1,000 watts. WERI still has to reduce power to 250 watts at night, as did all other stations on the same frequency. 1966 WERI adds F.M. service with WERI-FM/103.7 (Channel 279) (now WVEI-FM). The FM antenna is initially mounted to the side of the AM tower on Margin Street in downtown Westerly. The FM station broadcasts for only a few days from this location before it is shut down due to harmonic interference to TV channel 12. 1968 WERI-FM moves its transmitter to a new location on Route 3 in Ashaway, and beg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AMAX
AMAX is a certification program for AM radio broadcasting standards, created in the United States beginning in 1991 by the Electronic Industries Association (EIA) and the National Association of Broadcasters (NAB). It was developed with the intention of helping AM stations, especially ones with musical formats, become more competitive with FM broadcasters. The standards cover both consumer radio receivers and broadcasting station transmission chains. Although the Federal Communications Commission (FCC) endorsed the AMAX proposal, the agency never made it into a formal requirement, leaving its adoption as voluntary. Ultimately few receiver manufacturers and radio stations adhered to the standard, thus it has done little to stem the continued decline in AM station listenership. Standards Receiver AMAX radio receivers are divided into three categories: home, automotive and portable. Receiver certification requirements include: * Wide audio bandwidth, with a minimum of 7,500 hertz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WNMB
WNMB (900 AM, "El Gallo") is a radio station licensed to North Myrtle Beach, South Carolina, United States, and serves the greater Myrtle Beach area. The station is licensed by the Federal Communications Commission (FCC) to broadcast at 900 kHz with a power of 500 watts. The station previously went by the name "AM Stereo 900" and its slogan was "The Sound of North Myrtle Beach." The station most recently broadcast in high fidelity C-QUAM AM Stereo under a beach-oriented oldies format. Until August 1, 2015, WNMB was owned and operated by the family of Bill and Susi Norman who were original employees of the original WNMB when it signed on in 1972. WNMB FM existed from 1972-2000 when it was sold and the callsign changed to WEZV. Soon after, Bill Norman leased the AM station and changed the callsign to WNMB. Norman later purchased WNMB outright and continued the WNMB radio tradition on the Grand Strand. After several changes, the station broadcasts a Regional Mexican format. FM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CFCO
CFCO (630 AM) is a news, sports, and country music radio station located in Chatham–Kent, Ontario. The station, owned by London, Ontario, London, Ontario-based Blackburn Radio, features a heavy local news commitment. CFCO is one of the few dedicated country music stations on the AM dial in North America, as well as one of the few to do so in C-QUAM AM Stereo. History Classic Gold 630 The AM radio station has been on the air since 1926. CFCO, which stands for "Coming From Chatham Ontario", featured middle of the road (music), middle of the road and adult contemporary formats through much of its history, moving to an oldies format around 1992, as Classic Gold 630. The station made several upgrades during this period under the ownership of Bea-Ver Broadcasting, including an increase in nighttime power from 1,000 to 6,000 watts (the station broadcasts with 10,000 watts by day). The high quality of the AM stereo audio of CFCO was for a time even featured on a tuner manufacturer's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WXYG
WXYG (540 kHz AM) is an American radio station licensed to serve the community of Sauk Rapids, Minnesota, United States. The station is part of the Tri-County Broadcasting group and the license is held by the Herbert M. Hoppe Revocable Trust. WXYG broadcasts an album-oriented rock (AOR) format. History This station received its original construction permit from the Federal Communications Commission on July 26, 2007. The new station was assigned the call sign WXYG by the FCC on September 10, 2007. The call sign was changed to WMIN on August 12, 2008; to WPPI on December 2, 2008; and back to WXYG on December 14, 2009. This construction permit was scheduled to expire on July 25, 2010. As of November 8, 2010, WXYG, which had been occasionally testing with a mix of rock and country music since June, began playing Christmas music. The station resumed testing after the holiday season. On May 23, 2011, the FCC granted the station program test authority to begin broadcasting before receiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrature Amplitude Modulation
Quadrature amplitude modulation (QAM) is the name of a family of digital modulation methods and a related family of analog modulation methods widely used in modern telecommunications to transmit information. It conveys two analog message signals, or two digital bit streams, by changing (''modulating'') the amplitudes of two carrier waves, using the amplitude-shift keying (ASK) digital modulation scheme or amplitude modulation (AM) analog modulation scheme. The two carrier waves are of the same frequency and are out of phase with each other by 90°, a condition known as orthogonality or quadrature. The transmitted signal is created by adding the two carrier waves together. At the receiver, the two waves can be coherently separated (demodulated) because of their orthogonality property. Another key property is that the modulations are low-frequency/low-bandwidth waveforms compared to the carrier frequency, which is known as the narrowband assumption. Phase modulation (analog PM) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Myrtle Beach
North Myrtle Beach is a city in Horry County, South Carolina, United States. It was created in 1968 from four existing municipalities, and is located about northeast of Myrtle Beach. It serves as one of the primary tourist destinations along the Grand Strand. As of the 2010 census, the population was 13,752, and in 2019 the estimated population was 16,819. It is part of the Myrtle Beach–Conway–North Myrtle Beach Metropolitan Area, which had a combined population of 449,295 as of 2016. History In 1737, William Gause obtained a grant to of land near Windy Hill Beach. He farmed the area and also established a tavern for travelers along the Kings Highway. North Myrtle Beach was created in 1968 with the consolidation of Cherry Grove Beach, Crescent Beach, Ocean Drive Beach, and Windy Hill Beach. Geography North Myrtle Beach is located in eastern Horry County. It is bordered to the southwest by Briarcliffe Acres and to the northeast by Little River. Via U.S. Route 17, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CFCB
CFCB (570 kHz) is an AM radio station in Corner Brook, Newfoundland and Labrador, Canada. It broadcasts at a power of 10,000 watts by day and 1,000 watts at night. Owned by Stingray Group, CFCB first went on the air on October 3, 1960. The station was founded by Dr. Noel Murphy. On March 26, 2012, CFCB rebranded, which included a new slogan, logo and programming. The "Local News Now" slogan was adopted from VOCM in St. John's, which had rebranded just weeks before. The new CFCB logo also features the VOCM color scheme, which includes yellow and red. As of March 9, 2022, CFCB no longer originates any local programming from Corner Brook following the closure of its studios and termination of on-air personnel by Stingray. All content of this station is now simulcast from VOCM in St. John's, with the exception of local commercials. CFCB's sister station, CKXX-FM, also shared the same fate as it shared studio facilities and personalities. Rebroadcasters CFCB also operates rebroa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shortwave
Shortwave radio is radio transmission using shortwave (SW) radio frequencies. There is no official definition of the band, but the range always includes all of the high frequency band (HF), which extends from 3 to 30 MHz (100 to 10 metres); above the medium frequency band (MF), to the bottom of the VHF band. Radio waves in the shortwave band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the ionosphere. Therefore, short waves directed at an angle into the sky can be reflected back to Earth at great distances, beyond the horizon. This is called skywave or "skip" propagation. Thus shortwave radio can be used for communication over very long distances, in contrast to radio waves of higher frequency, which travel in straight lines (line-of-sight propagation) and are limited by the visual horizon, about 64 km (40 miles). Shortwave broadcasts of radio programs played an important role in the early days of radio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selective Fading
In wireless communications, fading is variation of the attenuation of a signal with various variables. These variables include time, geographical position, and radio frequency. Fading is often modeled as a random process. A fading channel is a communication channel that experiences fading. In wireless systems, fading may either be due to multipath propagation, referred to as multipath-induced fading, weather (particularly rain), or shadowing from obstacles affecting the wave propagation, sometimes referred to as shadow fading. Key concepts The presence of reflectors in the environment surrounding a transmitter and receiver create multiple paths that a transmitted signal can traverse. As a result, the receiver sees the superposition of multiple copies of the transmitted signal, each traversing a different path. Each signal copy will experience differences in attenuation, delay and phase shift while traveling from the source to the receiver. This can result in either construc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionosphere
The ionosphere () is the ionized part of the upper atmosphere of Earth, from about to above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on Earth. History of discovery As early as 1839, the German mathematician and physicist Carl Friedrich Gauss postulated that an electrically conducting region of the atmosphere could account for observed variations of Earth's magnetic field. Sixty years later, Guglielmo Marconi received the first trans-Atlantic radio signal on December 12, 1901, in St. John's, Newfoundland (now in Canada) using a kite-supported antenna for reception. The transmitting station in Poldhu, Cornwall, used a spark-gap transmitter to produce a signal with a freq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
