Medium frequency is the ITU designation for radio frequencies in the range of 300 kHz to 3 MHz. Part of this band is the medium wave AM broadcast band, the MF band is known as the hectometer band or hectometer wave as the wavelengths range from ten to one hectometer. Frequencies immediately below MF are denoted low frequency, while the first band of frequencies is known as high frequency. MF is mostly used for AM radio broadcasting, navigational beacons, maritime ship-to-shore communication. A major use of frequencies is AM broadcasting, AM radio stations are allocated frequencies in the medium wave broadcast band from 526.5 kHz to 1606. Although these are medium frequencies,120 meters is generally treated as one of the shortwave bands, there are a number of coast guard and other ship-to-shore frequencies in use between 1600 and 2850 kHz. These include, as examples, the French MRCC on 1696 kHz and 2677 kHz, Stornoway Coastguard on 1743 kHz,2182 kHz is the international calling and distress frequency for SSB maritime voice communication.
It is analogous to Channel 16 on the marine VHF band,500 kHz was for many years the maritime distress and emergency frequency, and there are more NDBs between 510 and 530 kHz. Navtex, which is part of the current Global Maritime Distress Safety System occupies 518 kHz and 490 kHz for important digital text broadcasts. Lastly, there are aeronautical and other mobile SSB bands from 2850 kHz to 3500 kHz, an amateur radio band known as 160 meters or top-band is between 1800 and 2000 kHz. Amateur operators transmit CW morse code, digital signals and SSB voice signals on this band, in recent years, some limited amateur radio operation has been allowed in the region of 500 kHz in the US, UK, Germany and Sweden. Propagation at MF wavelengths is via ground waves and reflection from the ionosphere, ground waves follow the contour of the Earth. MF broadcasting stations use ground waves to cover their listening areas, however at certain times the D layer can be electronically noisy and absorb MF radio waves, interfering with skywave propagation.
When this happens, MF radio waves can easily be received hundreds or even thousands of miles away as the signal will be refracted by the remaining F layer and this can be very useful for long-distance communication, but can interfere with local stations. Due to the number of available channels in the MW broadcast band. On nights of good skywave propagation, the signals of distant stations may reflect off the ionosphere and interfere with the signals of local stations on the same frequency. These channels are called clear channels, and the stations, called stations, are required to broadcast at higher powers of 10 to 50 kW. Transmitting antennas commonly used on this band include monopole mast radiators, top-loaded wire monopole antennas such as the inverted-L and T antennas, ground wave propagation, the most widely used type at these frequencies, requires vertically polarized antennas like monopoles
Low frequency or LF is the ITU designation for radio frequencies in the range of 30 kHz–300 kHz. As its wavelengths range from ten kilometres to one kilometre, respectively, LF radio waves exhibit low signal attenuation, making them suitable for long-distance communications. In Europe and areas of Northern Africa and Asia, part of the LF spectrum is used for AM broadcasting as the longwave band, in the western hemisphere, its main use is for aircraft beacon, navigation and weather systems. A number of time signal broadcasts are broadcast in this band, because of their long wavelength, low frequency radio waves can diffract over obstacles like mountain ranges and travel beyond the horizon, following the contour of the Earth. This mode of propagation, called ground wave, is the mode in the LF band. Ground waves must be polarized, so monopole antennas are used for transmitting. The attenuation of signal strength with distance by absorption in the ground is lower than at higher frequencies, low frequency ground waves can be received up to 2,000 kilometres from the transmitting antenna.
Low frequency waves can travel long distances by reflecting from the ionosphere, although this method. Reflection occurs at the ionospheric E layer or F layers, skywave signals can be detected at distances exceeding 300 kilometres from the transmitting antenna. In Europe and Japan, many low-cost consumer devices have since the late 1980s contained radio clocks with an LF receiver for these signals. Since these frequencies propagate by ground wave only, the precision of time signals is not affected by varying propagation paths between the transmitter, the ionosphere, and the receiver. In the United States, such devices became feasible for the market only after the output power of WWVB was increased in 1997 and 1999. Radio signals below 50 kHz are capable of penetrating ocean depths to approximately 200 metres, the longer the wavelength, the British, Indian, Swedish, United States and possibly other navies communicate with submarines on these frequencies. In addition, Royal Navy nuclear submarines carrying ballistic missiles are allegedly under standing orders to monitor the BBC Radio 4 transmission on 198 kHz in waters near the UK.
In the US, the Ground Wave Emergency Network or GWEN operated between 150 and 175 kHz, until replaced by satellite systems in 1999. GWEN was a land based military radio communications system which could survive, the 2007 World Radiocommunication Conference made this band a worldwide amateur radio allocation. An international 2.1 kHz allocation, the 2200 meter band, is available to amateur operators in several countries in Europe, New Zealand, Canada. The world record distance for a contact is over 10,000 km from near Vladivostok to New Zealand
In radio, written as long wave or long-wave, and commonly abbreviated LW, refers to parts of the radio spectrum with relatively long wavelengths. The term is an one, dating from the early 20th century, when the radio spectrum was considered to consist of long, medium. Most modern radio systems and devices use wavelengths which would have been considered ultra-short, in contemporary usage, the term longwave is not defined precisely, and its meaning varies across the world. Sometimes, part of the frequency band is included. The International Telecommunication Union Region 1 longwave broadcast band falls wholly within the low band of the radio spectrum. Broader definitions of longwave may extend below and/or above it, in the US, the Longwave Club of America is interested in frequencies below the AM broadcast band, i. e. all frequencies below 535 kHz. Because of their wavelength, radio waves in this frequency range can diffract over obstacles like mountain ranges and travel beyond the horizon. This mode of propagation, called ground wave, is the mode in the longwave band.
The attenuation of signal strength with distance by absorption in the ground is lower than at higher frequencies, Low frequency ground waves can be received up to 2,000 kilometres from the transmitting antenna. Low frequency waves can travel long distances by reflecting from the ionosphere, although this method. Reflection occurs at the ionospheric E layer or F layers, skywave signals can be detected at distances exceeding 300 kilometres from the transmitting antenna. Non-directional beacons transmit continuously for the benefit of radio direction finders in marine and they identify themselves by a callsign in Morse code. They can occupy any frequency in the range 190–1750 kHz, in North America, they occupy 190–535 kHz. In ITU Region 1 the lower limit is 280 kHz, there are government broadcast stations in the range 40–80 kHz that transmit coded time signals to radio clocks. Radio controlled clocks receive their time calibration signals with built-in long-wave receivers, long-waves travel by groundwaves that hug the surface of the earth, unlike medium-waves and short-waves.
Those higher-frequency signals do not follow the surface of the Earth beyond a few kilometers and these different propagation paths can make the time lag different for every signal received. The military of the United Kingdom, Russian Federation, United States, Germany, in North America during the 1970s, the frequencies 167,179 and 191 kHz were assigned to the short-lived Public Emergency Radio of the United States. Nowadays, in the United States, Part 15 of FCC regulations allow unlicensed use of 136 kHz and this is called Low Frequency Experimental Radio
Canberra is the capital city of Australia. With a population of 381,488, it is Australias largest inland city, the city is located at the northern end of the Australian Capital Territory,280 km south-west of Sydney, and 660 km north-east of Melbourne. A resident of Canberra is known as a Canberran, the site of Canberra was selected for the location of the nations capital in 1908 as a compromise between rivals Sydney and Melbourne, Australias two largest cities. It is unusual among Australian cities, being a planned city outside of any state, similar to Washington, D. C. in the United States. Following an international contest for the design, a blueprint by American architects Walter Burley Griffin and Marion Mahony Griffin was selected. The Griffins plan featured geometric motifs such as circles and triangles, the citys design was influenced by the garden city movement and incorporates significant areas of natural vegetation that have earned Canberra the title of the bush capital. Although the Australian Capital Territory is now self-governing, the Commonwealth Government retains some influence through the National Capital Authority, the Australian Armys officer corps is trained at the Royal Military College and the Australian Defence Force Academy is located in the capital.
The ACT is independent of any state to prevent any one state from gaining an advantage by hosting the seat of Commonwealth power, the ACT has voting representation in the Commonwealth Parliament, and has its own independent Legislative Assembly and government, similar to the states. Compared to the averages, the unemployment rate is lower. Property prices are high, in part due to comparatively restrictive development regulations. An 1830s map of the region by Major Mitchell indeed does mark the Sullivans Creek floodplain between two mountains as Nganbra. Nganbra or Nganbira could readily have been anglicised to the name Canberry, survey plans of the district dated 1837 refer to the area as the Canberry Plain. Although popularly pronounced /ˈkænbərə/ or /ˈkænbɛrə/, the pronunciation at its official naming in 1913 was /ˈkæn. brə/. Before white settlement, the area in which Canberra would eventually be constructed was seasonally inhabited by Indigenous Australians, archaeological evidence of settlement in the region includes inhabited rock shelters, rock paintings and engravings, burial places and quarry sites, and stone tools and arrangements.
Artefacts suggests early human activity occurred at some point in the area 21,000 years previously, European exploration and settlement started in the Canberra area as early as the 1820s. There were four expeditions between 1820 and 1824, white settlement of the area probably dates from 1823, when a homestead or station was built on what is now the Acton peninsula by stockmen employed by Joshua John Moore. He formally applied to purchase the site on 16 December 1826, on 30 April 1827, Moore was told by letter that he could retain possession of 1,000 acres at Canberry. The European population in the Canberra area continued to grow throughout the 19th century
Medium wave is the part of the medium frequency radio band used mainly for AM radio broadcasting. Practical groundwave reception typically extends to 200–300 miles, with distances over terrain with higher ground conductivity. Most broadcast stations use groundwave to cover their listening area, Medium waves can reflect off charged particle layers in the ionosphere and return to Earth at much greater distances, this is called the skywave. At night, especially in winter months and at times of low solar activity, when this happens, MF radio waves can easily be received many hundreds or even thousands of miles away as the signal will be reflected by the higher F layer. This can allow very long-distance broadcasting, but can interfere with distant local stations, due to the limited number of available channels in the MW broadcast band, the same frequencies are re-allocated to different broadcasting stations several hundred miles apart. On nights of good skywave propagation, the signals of distant station may interfere with the signals of local stations on the same frequency.
These channels are called clear channels, and they are required to broadcast at higher powers of 10 to 50 kW and this arrangement had numerous practical difficulties. The Commerce Department rarely intervened in such cases but left it up to stations to enter into voluntary timesharing agreements amongst themselves, the addition of a third entertainment wavelength,400 meters, did little to solve this overcrowding. In 1923, the Commerce Department realized that as more and more stations were applying for commercial licenses, on 15 May 1923, Commerce Secretary Herbert Hoover announced a new bandplan which set aside 81 frequencies, in 10 kHz steps, from 550 kHz to 1350 kHz. Each station would be assigned one frequency, no longer having to broadcast weather, class A and B stations were segregated into sub-bands. Today in most of the Americas, mediumwave broadcast stations are separated by 10 kHz and have two sidebands of up to ±5 kHz in theory, in the rest of the world, the separation is 9 kHz, with sidebands of ±4.5 kHz.
Both provide adequate quality for voice, but are insufficient for high-fidelity broadcasting. In the US and Canada the maximum power is restricted to 50 kilowatts. Those stations which shut down completely at night are known as daytimers. In most cases there are two limits, a lower one for omnidirectional and a higher one for directional radiation with minima in certain directions. The power limit can be depending on daytime and it is possible, other countries may only operate low-powered transmitters on the same frequency, again subject to agreement. For example, Russia operates a transmitter, located in its Kaliningrad exclave and used for external broadcasting. Due to the demand for frequencies in Europe, many countries operate single frequency networks, in Britain
2CA is a commercial radio station on the AM band in Canberra, which originally began broadcasting on 1050 kHz changing to 1053 kHz in 1978. 2CA has had many owners since its inception and is jointly owned by regional radio operators the Capital Radio Network. The stations current format is classic hits music and targets an audience aged 45+. By 1933 the station had increased its transmitter to 500 watts, the hill quickly became known as Radio Hill. By the late 1930s the 2CA studios were moved from Radio Hill to a new building in Mort Street, Canberra City, the transmitter power was increased again from 500 watts to 2,000 watts and moved to Gungahlin. In 1988, FM104 & Kix 106 went to air as Australias first supplementary FM licences, FM104 was a supplementary licence of 2CA, and Kix 106 a supplementary licence of 2CC. Over the years the 2CA studios were housed in buildings in the City including 64 Northbourne Avenue and the first floor of the Jolimont Building. The 2CA studios had to be evacuated on 29 November 1993 when a man crashed his car into the floor of the Jolimont Building.
Staff from both 2CA and FM104.7 had to be rescued from their first floor studio by smashing a window, both 2CA and 2CC were moved to their current shared studio building in the Canberra suburb of Mitchell. In 2004 Grant Broadcasters purchased part ownership of Radio Canberra Pty Ltd to form a joint venture with the Capital Radio Network, since then, the broadcast range of the channel has been focused almost exclusively on Canberra. It covers some neighbouring districts extending as far as Yass in the North, Tharwa in the South and Bungendore in the West
TDF time signal
TéléDiffusion de France broadcast the TDF time signal, controlled by LNE–SYRTE, from the Allouis longwave transmitter at 162 kHz, with a power of 2 MW. It was known as FI or France Inter because the signal was formerly best known for broadcasting the France Inter AM signal and this signal ceased at the end of 2016, but the transmitter remains in use for its time signal and other digital signals. In 1980, the first atomic clock was installed to regulate the carrier frequency and it requires a more complex receiver than the popular DCF77 service, but the much more powerful transmitter gives it a much greater range of 3500 km. The signal is almost continuous but there is a regularly scheduled interruption for maintenance every Tuesday and this used to be from 01,03 to 05,00, but with the cessation of audio signals, it has been moved to 08,00 to 12,00. The signal was formerly 2000 kW, but has reduced to 1500 kW. TéléDiffusion de France uses an amplitude modulated longwave transmitter station, Time signals are transmitted by phase-modulating the carrier by ±1 radian in 0.1 s every second except the 59th second of each minute.
This modulation pattern is repeated to indicate a binary one, the time transmitted is the local time of the upcoming minute. Bit 15 is reserved to indicate abnormal transmitter operation, as extensions to the DCF77 code, bit 14 is set during public holidays, and bit 13 is set the day before public holidays. Unlike DCF77, bit 19 is not used for leap second warnings, bit 1 is used to warn of a positive leap second, and bit 2 is used to warn of a negative leap second. In case of a second, an additional zero bit is inserted between bits 2 and 3. The relative uncertainty of the frequency is 2 parts in 1012. One signal element is sent at each second between 0 and 58. Two signal elements are sent in sequence to represent a binary one, during ramp B of the initial signal element, the exact point the signal phase is at zero represents the top of the UTC second. Since the phase is the integral of the frequency, this phase modulation at 40 rad/s corresponds to a square frequency modulation with a deviation of 20/π ≈6.37 Hz.
Both the average phase and the frequency deviation are thus zero. Additional non-timing data is sent by phase modulation during the rest of each second, but the second marker is always preceded by 100 ms without any phase modulation. The signal is not phase-modulated at all during the 59th second past the minute, loop antenna Allouis longwave transmitter, the facility used for its transmission. Standard Frequency and Time Signal Stations On Longwave and Shortwave, archived from the original on 2006-08-18
AM broadcasting is the process of radio broadcasting using amplitude modulation. AM was the first method of impressing sound on a signal and is still widely used today. Commercial and public AM broadcasting is authorized in the wave band worldwide. Commercial AM broadcasting developed from amateur broadcasts around 1920, and was the commercially important form of radio broadcasting until FM broadcasting began after World War II. This period is known as the Golden Age of Radio, today, AM competes with FM, as well as with various digital radio broadcasting services distributed from terrestrial and satellite transmitters. AM broadcasting was the first broadcasting technology invented, the technology of amplitude modulation radio transmission was developed between 1900 and 1920. This was used for private communication and message traffic, such as telegrams. The entrepreneurs who developed AM radiotelephone transmission did not anticipate broadcasting voice, the term broadcasting, borrowed from agriculture, was applied to this new activity around 1920.
Prior to 1920 there was no concept of broadcasting, or that radio listeners could be a market for entertainment. Although there were a number of broadcasts during this period. True radio broadcasting didnt begin until around 1920, when it sprang up spontaneously among amateur stations, AM remained the dominant method of broadcasting for the next 30 years, a period called the Golden Age of Radio, until FM broadcasting started to become widespread in the 1950s. AM remains a popular, profitable entertainment medium today and the dominant form of broadcasting in some such as Australia. The first AM voice transmission was made by Canadian researcher Reginald Fessenden on 23 December 1900, Fessenden is a significant figure in the development of AM radio. He helped develop one of the first – the Alexanderson alternator, the first practical continuous wave AM transmitters were based on versions of the Poulsen arc transmitter invented in 1903, and the huge, expensive Alexanderson alternator, developed 1906–1910.
The modifications necessary to transmit AM were clumsy and resulted in low audio quality. Modulation was usually accomplished by a carbon microphone inserted directly in the antenna wire, the limited power handling ability of the microphone severely limited the power of the first radiotelephones, in powerful transmitters water-cooled microphones had to be used. At the receiving end, the crystal radio receivers in use could not drive loudspeakers, only earphones. The discovery in 1912 of the ability of the Audion vacuum tube, invented in 1906 by Lee De Forest
Nagoya is the largest city in the Chūbu region of Japan. It is Japans third-largest incorporated city and the fourth most populous urban area and it is located on the Pacific coast on central Honshu. It is the capital of Aichi Prefecture and is one of Japans major ports along with those of Tokyo, Kobe, Chiba and it is the center of Japans third-largest metropolitan region, known as the Chūkyō Metropolitan Area. As of 2015,2.28 million people lived in the city, the citys name was historically written as 那古野 or 名護屋. One possible origin is the adjective nagoyaka, meaning peaceful, the name Chūkyō is used to refer to Nagoya. Notable examples of the use of the name Chūkyō include the Chūkyō Industrial Area, Chūkyō Metropolitan Area, Chūkyō Television Broadcasting, Chukyo University, oda Nobunaga and his protégés Toyotomi Hideyoshi and Tokugawa Ieyasu were powerful warlords based in the Nagoya area who gradually succeeded in unifying Japan. In 1610, Tokugawa Ieyasu moved the capital of Owari Province from Kiyosu, about seven kilometers away, during this period Nagoya Castle was constructed, built partly from materials taken from Kiyosu Castle.
During the construction, the town around Kiyosu Castle, consisting of around 60,000 people. Around the same time, the nearby ancient Atsuta Shrine was designated as a waystation, called Miya, on the important Tōkaidō road, a town developed around the temple to support travelers. The castle and shrine towns formed the city, during the Meiji Restoration Japans provinces were restructured into prefectures and the government changed from family to bureaucratic rule. Nagoya was proclaimed a city on October 1,1889, and designated a city on September 1,1956, Nagoya became an industrial hub for the region. Its economic sphere included the famous pottery towns of Tokoname and Seto, as well as Okazaki, other industries included cotton and complex mechanical dolls called karakuri ningyō. Mitsubishi Aircraft Company was established in 1920 in Nagoya and became one of the largest aircraft manufacturers in Japan, the availability of space and the central location of the region and the well-established connectivity were some of the major factors that lead to the establishment of the aviation industry there.
Nagoya was the target of US air raids during World War II, the population of Nagoya at this time was estimated to be 1.5 million, fourth among Japanese cities and one of the three largest centers of the Japanese aircraft industry. It was estimated that 25% of its workers were engaged in aircraft production, important Japanese aircraft targets were within the city itself, while others were to the north of Kagamigahara. It was estimated that produced between 40% and 50% of Japanese combat aircraft and engines, such as the vital Mitsubishi A6M Zero fighter. The Nagoya area produced machine tools, railway equipment, metal alloys, motor vehicles, the bombing continued through the spring of 1945, and included large-scale firebombing. Nagoya was the target of two of Bomber Command’s attacks and these incendiary attacks, one by day and one by night, devastated 15.3 square kilometres
A radio clock or radio-controlled clock is a clock that is automatically synchronized by a time code transmitted by a radio transmitter connected to a time standard such as an atomic clock. Such a clock may be synchronized to the time sent by a transmitter, such as many national or regional time transmitters, or may use multiple transmitters. Such systems may be used to set clocks or for any purpose where accurate time is needed. The radio controlled clock will contain a time base oscillator to maintain timekeeping if the radio signal is momentarily unavailable. Other radio controlled clocks use the signals transmitted by dedicated transmitters in the shortwave bands. Systems using dedicated time signal stations can achieve accuracy of a few tens of milliseconds, GPS satellite navigation receivers internally generate accurate time information from the satellite signals. General purpose or consumer grade GPS may have an offset of up to one second between the calculated time, which is much more accurate than 1 second, and the time displayed on the screen.
Other broadcast services may include timekeeping information of varying accuracy within their signals, Radio clocks depend on coded time signals from radio stations. The stations vary in broadcast frequency, in location. In general, each station has its own format for the time code, many other countries can receive these signals, but success depends on the time of day, atmospheric conditions, and interference from intervening buildings. Reception is generally better if the clock is placed near a window facing the transmitter, there is a transit delay of approximately 1 ms for every 300 km the receiver is from the transmitter. A number of manufacturers and retailers sell radio clocks that receive coded time signals from a radio station, one of the first radio clocks was offered by Heathkit in late 1983. Their model GC-1000 Most Accurate Clock received shortwave time signals from radio station WWV in Fort Collins and it automatically switched between WWVs 5,10, and 15 MHz frequencies to find the strongest signal as conditions changed through the day and year.
It kept time during periods of poor reception with a quartz-crystal oscillator and this oscillator was disciplined, meaning that the microprocessor-based clock used the highly accurate time signal received from WWV to trim the crystal oscillator. The timekeeping between updates was thus more accurate than the crystal alone could have achieved. Time down to the tenth of a second was shown on an LED display, the GC-1000 originally sold for US$250 in kit form, US$400 preassembled, and was considered impressive at the time. Heath Company was granted a patent for its design, in the 2000s radio-based atomic clocks became common in retail stores, as of 2010 prices start at around US$15 in many countries. Clocks may have features such as indoor thermometers and weather station functionality
Chubu-Nippon Broadcasting Co. Ltd. is a regional radio and television service serving Nagoya, Aichi Prefecture, Japan. Its radio service is affiliated with the Japan Radio Network and its television service affiliated with the Japan News Network, CBC was established in 1950 as Japans first commercial radio broadcaster. Television broadcasts were introduced on December 1,1956, in 2013, the radio and television companies spun off. CBC operates the C-Wave advertising agency, frequency Nagoya,1053 kHz, JOAR,93. Smile. -13, 55-15,50 ja, 花咲かタイムズ9, 25-11,30 every Suterday Dramas produced by CBC Hirudora era Kippari. Over 30 Dorama 30 era Kids War Series Kippari