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40-661: The interest of the Jacksonville Journal Company, known until 1952 as the Metropolis Company, in television had been made manifest as early as 1948. In May 1948, it applied for VHF channel 8 to go with its existing radio station holdings, the WJHP radio stations, named for company owner John H. Perry. This application was granted by the Federal Communications Commission on August 13, 1948. However,

80-542: A nightclub opened during World War II , had not performed as expected in spite of being among the "plushest" such establishments in northern Florida. WJHP-TV signed affiliation agreements with the NBC and ABC networks in November. WJHP-TV began broadcasting a test pattern on November 30, 1953, and programming on December 13. Over its history, ownership constantly fought for a VHF channel to be made available for their use. In 1955,

120-499: A process to move these stations to UHF bands to free up valuable VHF spectrum for its original purpose of FM radio. In addition, by 1985 the federal government decided new TV stations are to be broadcast on the UHF band. Two new VHF channels, 9A and 12, have since been made available and are being used primarily for digital services (e.g. ABC in capital cities) but also for some new analogue services in regional areas. Because channel 9A

160-666: A proposed transmitter station. VHF is the first band at which wavelengths are small enough that efficient transmitting antennas are short enough to mount on vehicles and handheld devices, a quarter wave whip antenna at VHF frequencies is 25 cm to 2.5 meter (10 inches to 8 feet) long. So the VHF and UHF wavelengths are used for two-way radios in vehicles, aircraft, and handheld transceivers and walkie-talkies . Portable radios usually use whips or rubber ducky antennas , while base stations usually use larger fiberglass whips or collinear arrays of vertical dipoles. For directional antennas,

200-505: A result, FM radio receivers such as those found in automobiles which are designed to tune into this frequency range could receive the audio for analog-mode programming on the local TV channel 6 while in North America. The practice largely ended with the DTV transition in 2009, although some still exist. The FM broadcast channel at 87.9 MHz is normally off-limits for FM audio broadcasting; it

240-524: Is a radio band which, in most of the world, is used for FM broadcasting . In North America , however, this bandwidth is allocated to VHF television channel 6 (82–88 MHz). The analog audio for TV channel 6 is broadcast at 87.75 MHz (adjustable down to 87.74). Several stations, known as Frankenstations , most notably those joining the Pulse 87 franchise, have operated on this frequency as radio stations, though they use television licenses. As

280-1049: Is available in the FM broadcast band for purposes such as micro-broadcasting and sending output from CD or digital media players to radios without auxiliary-in jacks, though this is illegal in some other countries. This practice was legalised in the United Kingdom on 8 December 2006. ELF 3 Hz/100 Mm 30 Hz/10 Mm SLF 30 Hz/10 Mm 300 Hz/1 Mm ULF 300 Hz/1 Mm 3 kHz/100 km VLF 3 kHz/100 km 30 kHz/10 km LF 30 kHz/10 km 300 kHz/1 km MF 300 kHz/1 km 3 MHz/100 m HF 3 MHz/100 m 30 MHz/10 m VHF 30 MHz/10 m 300 MHz/1 m UHF 300 MHz/1 m 3 GHz/100 mm SHF 3 GHz/100 mm 30 GHz/10 mm EHF 30 GHz/10 mm 300 GHz/1 mm THF 300 GHz/1 mm 3 THz/0.1 mm Radio frequency Radio frequency ( RF )

320-558: Is less of a problem in this and higher frequency bands than at lower frequencies. The VHF band is the first band at which efficient transmitting antennas are small enough that they can be mounted on vehicles and portable devices, so the band is used for two-way land mobile radio systems , such as walkie-talkies , and two way radio communication with aircraft ( Airband ) and ships ( marine radio ). Occasionally, when conditions are right, VHF waves can travel long distances by tropospheric ducting due to refraction by temperature gradients in

360-463: Is not used for television services in or near Sydney, Melbourne, Brisbane, Adelaide or Perth, digital radio in those cities are broadcast on DAB frequencies blocks 9A, 9B and 9C. VHF radio is also used for marine Radio as per its long-distance reachability comparing UHF frequencies. Example allocation of VHF–UHF frequencies: Until 2013, the four main free-to-air TV stations in New Zealand used

400-592: Is reserved for displaced class D stations which have no other frequencies in the normal 88.1–107.9 MHz subband to move to. So far, only two stations have qualified to operate on 87.9 MHz: 10–watt KSFH in Mountain View, California and 34–watt translator K200AA in Sun Valley, Nevada . In some countries, particularly the United States and Canada, limited low-power license-free operation

440-541: Is the ITU designation for the range of radio frequency electromagnetic waves ( radio waves ) from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten meters to one meter. Frequencies immediately below VHF are denoted high frequency (HF), and the next higher frequencies are known as ultra high frequency (UHF). VHF radio waves propagate mainly by line-of-sight , so they are blocked by hills and mountains, although due to refraction they can travel somewhat beyond

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480-399: Is the oscillation rate of an alternating electric current or voltage or of a magnetic , electric or electromagnetic field or mechanical system in the frequency range from around 20  kHz to around 300  GHz . This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies, and also encompasses the microwave range. These are

520-735: The HF band there is only some reflection at lower frequencies from the ionosphere ( skywave propagation). They do not follow the contour of the Earth as ground waves and so are blocked by hills and mountains, although because they are weakly refracted (bent) by the atmosphere they can travel somewhat beyond the visual horizon out to about 160 km (100 miles). They can penetrate building walls and be received indoors, although in urban areas reflections from buildings cause multipath propagation , which can interfere with television reception. Atmospheric radio noise and interference ( RFI ) from electrical equipment

560-611: The Yagi antenna is the most widely used as a high gain or "beam" antenna. For television reception, the Yagi is used, as well as the log-periodic antenna due to its wider bandwidth. Helical and turnstile antennas are used for satellite communication since they employ circular polarization . For even higher gain, multiple Yagis or helicals can be mounted together to make array antennas . Vertical collinear arrays of dipoles can be used to make high gain omnidirectional antennas , in which more of

600-597: The visual horizon out to about 160 km (100 miles). Common uses for radio waves in the VHF band are Digital Audio Broadcasting (DAB) and FM radio broadcasting, television broadcasting , two-way land mobile radio systems (emergency, business, private use and military), long range data communication up to several tens of kilometers with radio modems , amateur radio , and marine communications . Air traffic control communications and air navigation systems (e.g. VOR and ILS ) work at distances of 100 kilometres (62 miles) or more to aircraft at cruising altitude. In

640-435: The 10 VHF channels were insufficient to support the growth of television services. This was rectified by the addition of three additional frequencies-channels 0, 5A and 11. Older television sets using rotary dial tuners required adjustment to receive these new channels. Most TVs of that era were not equipped to receive these broadcasts, and so were modified at the owners' expense to be able to tune into these bands; otherwise

680-504: The 50 or 60 Hz current used in electrical power distribution . The radio spectrum of frequencies is divided into bands with conventional names designated by the International Telecommunication Union (ITU): Frequencies of 1 GHz and above are conventionally called microwave , while frequencies of 30 GHz and above are designated millimeter wave . More detailed band designations are given by

720-538: The 625-line colour signal), with the exception of BBC2 (which had always broadcast solely on UHF). The last British VHF TV transmitters closed down on January 3, 1985. VHF band III is now used in the UK for digital audio broadcasting , and VHF band II is used for FM radio , as it is in most of the world. Unusually, the UK has an amateur radio allocation at 4 metres , 70–70.5 MHz. Frequency assignments between US and Canadian users are closely coordinated since much of

760-453: The Americas and many other parts of the world, VHF Band I was used for the transmission of analog television . As part of the worldwide transition to digital terrestrial television most countries require broadcasters to air television in the VHF range using digital, rather than analog encoding. Radio waves in the VHF band propagate mainly by line-of-sight and ground-bounce paths; unlike in

800-549: The Canadian population is within VHF radio range of the US border. Certain discrete frequencies are reserved for radio astronomy . The general services in the VHF band are: Cable television , though not transmitted aerially, uses a spectrum of frequencies overlapping VHF. The U.S. FCC allocated television broadcasting to a channelized roster as early as 1938 with 19 channels. That changed three more times: in 1940 when Channel 19

840-607: The FCC deleted the WJHP-TV construction permit at the Jacksonville Journal Company's request. The channel was not used again. Rust Craft Broadcasting applied for channel 36 in 1963, but after obtaining the permit, it applied to switch to channel 17 in service of its efforts to obtain network affiliation. The FCC approved this request in August 1964, and Rust Craft put WJKS-TV on the air on February 19, 1966. VHF Very high frequency ( VHF )

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880-532: The FCC's reallocation plan after the freeze removed channel 8 from Jacksonville. Instead, the Jacksonville Journal Company reapplied for UHF channel 36 on December 5, 1952. A second application was filed for the channel by WEAR in Pensacola , but a settlement agreement was reached in early June. The John H. Perry–owned station in Pensacola, WCOA , withdrew its request for channel 3 there, and WEAR in turn pulled out of

920-604: The Jacksonville market all-VHF or all-UHF—as it had in similarly situated markets such as New Orleans and Duluth, Minnesota , which had one VHF and one UHF outlet in operation and a final decision pending for a second VHF station. In the appeal, Perry Jr. indicated that from December 1953 to June 30, 1956, the station had incurred operating losses of $ 448,900 in addition to $ 561,575 in construction expenses, and NBC had become noncommittal as to continuing its affiliation with WJHP-TV; previously, NBC had told WJHP-TV that it would move to

960-468: The VHF television bands ( Band I and Band III ) to transmit to New Zealand households. Other stations, including a variety of pay and regional free-to-air stations, were forced to broadcast in the UHF band, since the VHF band had been very overloaded with four stations sharing a very small frequency band, which was so overcrowded that one or more channels would not be available in some smaller towns. However, at

1000-455: The antenna's power is radiated in horizontal directions. Television and FM broadcasting stations use collinear arrays of specialized dipole antennas such as batwing antennas . Certain subparts of the VHF band have the same use around the world. Some national uses are detailed below. The VHF TV band in Australia was originally allocated channels 1 to 10-with channels 2, 7 and 9 assigned for

1040-427: The atmosphere. VHF transmission range is a function of transmitter power, receiver sensitivity, and distance to the horizon, since VHF signals propagate under normal conditions as a near line-of-sight phenomenon. The distance to the radio horizon is slightly extended over the geometric line of sight to the horizon, as radio waves are weakly bent back toward the Earth by the atmosphere. An approximation to calculate

1080-456: The channel 36 fight in Jacksonville. This resulted in WEAR-TV being approved in Pensacola and WJHP-TV in Jacksonville. With the permit awarded, work began on putting the new station on the air. In August, a subsidiary of the Jacksonville Journal Company purchased the former Peacock Club, a nightclub on Philips Highway , to be refitted as the home of its radio and television operations. The Peacock,

1120-522: The current proliferation of radio frequency wireless telecommunications devices such as cellphones . Medical applications of radio frequency (RF) energy, in the form of electromagnetic waves ( radio waves ) or electrical currents, have existed for over 125 years, and now include diathermy , hyperthermy treatment of cancer, electrosurgery scalpels used to cut and cauterize in operations, and radiofrequency ablation . Magnetic resonance imaging (MRI) uses radio frequency fields to generate images of

1160-468: The end of 2013 , all television channels stopped broadcasting on the VHF bands, as New Zealand moved to digital television broadcasting, requiring all stations to either broadcast on UHF or satellite (where UHF was unavailable) utilising the Freeview service. Refer to Australasian television frequencies for more information. British television originally used VHF band I and band III . Television on VHF

1200-446: The frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves , so they are used in radio technology, among other uses. Different sources specify different upper and lower bounds for the frequency range. Electric currents that oscillate at radio frequencies ( RF currents ) have special properties not shared by direct current or lower audio frequency alternating current , such as

1240-413: The human body. Radio Frequency or RF energy is also being used in devices that are being advertised for weight loss and fat removal. The possible effects RF might have on the body and whether RF can lead to fat reduction needs further study. Currently, there are devices such as trusculpt ID , Venus Bliss and many others utilizing this type of energy alongside heat to target fat pockets in certain areas of

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1280-552: The initial services in Sydney and Melbourne , and later the same channels were assigned in Brisbane , Adelaide and Perth . Other capital cities and regional areas used a combination of these and other frequencies as available. The initial commercial services in Hobart and Darwin were respectively allocated channels 6 and 8 rather than 7 or 9. By the early 1960s it became apparent that

1320-408: The line-of-sight horizon distance (on Earth) is: These approximations are only valid for antennas at heights that are small compared to the radius of the Earth. They may not necessarily be accurate in mountainous areas, since the landscape may not be transparent enough for radio waves. In engineered communications systems, more complex calculations are required to assess the probable coverage area of

1360-445: The new channel 12 whenever it was granted. The appeals court upheld the channel 12 grant in May 1957. A second appeal to have channel 7 made commercial, or alternatively to change channel 12 to UHF channel 46, was denied. Florida-Georgia Television Company's station, WFGA-TV , began broadcasting as an NBC affiliate on September 1, 1957. John H. Perry Jr. announced on October 15, 1957, that

1400-513: The owner had to buy a new TV. Several TV stations were allocated to VHF channels 3, 4 and 5, which were within the FM radio bands although not yet used for that purpose. A couple of notable examples were NBN-3 Newcastle , WIN-4 Wollongong and ABC Newcastle on channel 5. While some Channel 5 stations were moved to 5A in the 1970s and 80s, beginning in the 1990s, the Australian Broadcasting Authority began

1440-465: The standard IEEE letter- band frequency designations and the EU/NATO frequency designations. Radio frequencies are used in communication devices such as transmitters , receivers , computers , televisions , and mobile phones , to name a few. Radio frequencies are also applied in carrier current systems including telephony and control circuits. The MOS integrated circuit is the technology behind

1480-616: The station and local educators made a proposal whereby the Duval County school system would receive the channel 36 facility for educational broadcasting if the reserved channel 7 were reclassified to permit commercial use. The Jacksonville Journal Company protested after the FCC awarded channel 12 to the Florida-Georgia Television Company in September 1956. It believed the FCC should have enacted "deintermixture"—the making of

1520-600: The station would leave the air on October 25, its problems having been exacerbated by WFGA-TV's debut. Perry believed that the only way that a third station in the market could be successful was the addition of a VHF channel to Jacksonville, and hoped that the FCC would provide relief. A country music program hosted by a young Johnny Tillotson , still attending the University of Florida at the time, moved from WJHP-TV to WFGA-TV after channel 36 folded. Perry's desire for an additional VHF channel never came to pass, and in August 1960,

1560-406: Was deleted and several channels changed frequencies, then in 1946 with television going from 18 channels to 13 channels, again with different frequencies, and finally in 1948 with the removal of Channel 1 (analog channels 2–13 remain as they were, even on cable television ). Channels 14–19 later appeared on the UHF band, while channel 1 remains unused. 87.5–87.9 MHz

1600-399: Was in black and white with 405-line format (although there were experiments with all three colour systems- NTSC , PAL , and SECAM -adapted for the 405-line system in the late 1950s and early 1960s). British colour television was broadcast on UHF (channels 21–69), beginning in the late 1960s. From then on, TV was broadcast on both VHF and UHF (VHF being a monochromatic downconversion from

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