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Very high frequency

"VHF" redirects here. For the diseases, see Viral hemorrhagic fever.

Very high frequency (VHF) 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).

Very high frequency
Frequency range
30 MHz to 300 MHz
Wavelength range
10 to 1 m
VHF television antennas used for broadcast television reception. These six antennas are a type known as a Yagi antenna, which is widely used at VHF

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 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 & ILS) work at distances of 100 kilometres (62 mi) or more to aircraft at cruising altitude.

In 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 format.

Contents

Radio waves in the VHF band propagate mainly by line-of-sight and ground-bounce paths; unlike in 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 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 the atmosphere.

"Rabbit-ears" VHF television antenna (the small loop is a separate UHF antenna).

For analog TV, 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 the line-of-sight horizon distance (on Earth) is:

  • distance in nautical miles = 1.23 × A f {\displaystyle 1.23\times {\sqrt {A_{f}}}} where A f {\displaystyle A_{f}} is the height of the antenna in feet[citation needed]
  • distance in kilometers = 12.746 × A m {\displaystyle {\sqrt {12.746\times A_{m}}}} where A m {\displaystyle A_{m}} is the height of the antenna in meters.[citation needed]

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 a proposed transmitter station.[citation needed]

The accuracy of these calculations for digital TV signals is being debated.

A VHF television broadcasting antenna. This is a common type called a super turnstile or batwing antenna.

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, 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 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.

A plan showing VHF use in television, FM radio, amateur radio, marine radio and aviation.

Australia

The VHF TV band in Australia was originally allocated channels 1 to 10-with channels 2, 7 and 9 assigned for 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 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 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 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, 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 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:

  • Radionavigation 60: 84–86 MHz
  • Fixed Maritime Mobile: 130–135.7 MHz
  • Fixed Aeronautical radio navigation: 160–190 MHz
  • Broadcasting Aeronautical Radionavigation: 255–283.5 MHz
  • Aeronautical Radionavigation AUS 49 / Maritime Radionavigation (radiobeacons) 73: 315–325 MHz

New Zealand

  • 44–51, 54–68 MHz: Band I Television (channels 1–3)
  • 87.5–108 MHz: Band II Radio
  • 174–230 MHz: Band III Television (channels 4–11)

Until 2013, the four main Free-to-Air TV stations in New Zealand used 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 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.

United Kingdom

This section does not cite any sources. Please help improve this section by . Unsourced material may be challenged and removed.(August 2016) ()

British television originally used VHF band I and band III. Television on VHF 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 60s).

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 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.

United States and Canada

Frequency assignments between US and Canadian users are closely coordinated since much of 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:

  • 30–49.6 MHz: Licensed 2-way land mobile communication, with various sub-bands.
  • 30–88 MHz: Military VHF FM, including SINCGARS
  • 43–50 MHz: Cordless telephones, 49 MHz FM walkie-talkies and radio controlled toys, and mixed 2-way mobile communication. The FM broadcast band originally operated here (42–50 MHz) before it was moved to 88–108 MHz.
  • 50–54 MHz: Amateur radio 6-meter band
  • 54–88 MHz, known as "Band I" internationally; some DTV stations will appear here. See North American broadcast television frequencies
    • 54–72 MHz TV channels 2–4 (VHF-Lo)
    • 72–76 MHz: Radio controlled models, industrial remote control, and other devices. Model aircraft operate on 72 MHz while surface models operate on 75 MHz in the US and Canada, air navigation beacons 74.8–75.2 MHz.
    • 76–88 MHz TV channels 5–6 (VHF-Lo)
  • 87.5–108 MHz: FM radio broadcasting (87.9–91.9 non-commercial, 92–108 commercial in the United States) (known as "Band II" internationally)
  • 108–118 MHz: Air navigation beacons VOR
  • 118–137 MHz: Airband for air traffic control, AM
    • 121.5 MHz is an emergency frequency
  • 137–138 MHz Space research, space operations, meteorological satellite
  • 138–144 MHz: Land mobile, auxiliary civil services, satellite, space research, and other miscellaneous services
  • 144–148 MHz: Amateur radio 2-meter band
  • 148–150 MHz: Land mobile, fixed, satellite
  • 150–156 MHz: "VHF business band," public safety, the unlicensed Multi-Use Radio Service (MURS), and other 2-way land mobile, FM
  • 156–158 MHz VHF Marine Radio
    • 156.8 MHz (Channel 16) is the maritime emergency and contact frequency.
  • 159.81-161.565 MHz railways
    • 159.81–160.2 are railroads in Canada only and is used by trucking companies in the U.S.
  • 160.6–162 Wireless microphones and TV/FM broadcast remote pickup
  • 162.4–162.55: NOAA Weather Stations, narrowband FM, Weatheradio Canada Stations
  • 174–240 MHz, known as "Band III" internationally. A number of DTV channels have begun broadcasting here, especially many of the stations which were assigned to these channels for previous analog operation.
    • 174–216 MHz television channels 7–13 (VHF-Hi)
    • 174–216 MHz: professional wireless microphones (low power, certain exact frequencies only)
    • 216–222 MHz: land mobile, fixed, maritime mobile,
    • 222–225 MHz: 1.25 meters (US) (Canada 219–220, 222–225 MHz) amateur radio
  • 225 MHz and above (UHF): Military aircraft radio, 243 MHz is an emergency frequency (225–400 MHz) AM, including HAVE QUICK, dGPS RTCM-104

Cable television, though not transmitted aerially, uses a spectrum of frequencies overlapping VHF.

VHF television

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 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

87.5–87.9 MHz is a radio frequency 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 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 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 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.

  1. The 42 MHz Segment is still in current use by the California Highway Patrol, New Jersey State Police, Tennessee Highway Patrol, and other state law enforcement agencies.
  2. The 160 and 161 areas are Association of American Railroads (AAR) 99 channel railroad radios, issued to the railroad. For example, AAR 21 is 160.425 MHz and that is issued to Tennessee Valley Railroad Museum, as well as other railroads that want AAR Channel 21.
  1. "Rec. ITU-R V.431-7, Nomenclature of the frequency and wavelength bands used in telecommunications"(PDF). ITU. Archived from the original(PDF) on 31 October 2013. Retrieved20 February 2013.
  2. Seybold, John S. (2005). Introduction to RF Propagation. John Wiley and Sons. pp. 9–10. ISBN 978-0471743682.
  3. Grotticelli, Michael (2009-06-22). "DTV Transition Not So Smooth in Some Markets". Broadcast Engineering. Archived from the original on June 28, 2009. Retrieved2009-06-24.
  4. "Marine VHF radio". ACMA.
  5. "Australian radiofrequency spectrum plan". Planning. ACMA.
  6. "Going Digital - When is my area going digital?". goingdigital.co.nz. Ministry for Culture and Heritage. Archived from the original on 17 October 2011. Retrieved20 October 2011.
  7. [1]
  8. Canadian Table of Frequency Allocations 9 kHz – 275 GHz (2005 (revised February 2007) ed.). Industry Canada. February 2007. pp. 29–30.
  9. "Cable TV Channel Frequencies". www.jneuhaus.com. Archived from the original on 23 August 2017. Retrieved27 April 2018.
  10. "What Ever Happened to Channel 1?". tech-notes.tv. Tech Notes. Table 1. Archived from the original on 17 March 2017. Retrieved27 April 2018.
  11. "Change to the law to allow the use of low power FM transmitters for MP3 players". Ofcom. 23 November 2006. Archived from the original on 7 August 2011. Retrieved2 October 2012.

Very high frequency
Very high frequency Language Watch Edit VHF redirects here For the diseases see Viral hemorrhagic fever Very high frequency VHF is the ITU designation 1 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 Very high frequencyFrequency range30 MHz to 300 MHzWavelength range10 to 1 mVHF television antennas used for broadcast television reception These six antennas are a type known as a Yagi antenna which is widely used at VHF 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 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 amp ILS work at distances of 100 kilometres 62 mi or more to aircraft at cruising altitude In 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 format Contents 1 Propagation characteristics 2 Line of sight calculation 3 Antennas 4 Universal use 5 By country 5 1 Australia 5 2 New Zealand 5 3 United Kingdom 5 4 United States and Canada 5 4 1 VHF television 5 4 2 87 5 87 9 MHz 6 Unlicensed operation 7 See also 8 Notes 9 ReferencesPropagation characteristics EditRadio waves in the VHF band propagate mainly by line of sight and ground bounce paths unlike in the HF band there is only some reflection at lower frequencies from the ionosphere skywave propagation 2 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 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 the atmosphere Line of sight calculation Edit Rabbit ears VHF television antenna the small loop is a separate UHF antenna For analog TV 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 the line of sight horizon distance on Earth is distance in nautical miles 1 23 A f displaystyle 1 23 times sqrt A f where A f displaystyle A f is the height of the antenna in feet citation needed distance in kilometers 12 746 A m displaystyle sqrt 12 746 times A m where A m displaystyle A m is the height of the antenna in meters citation needed 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 a proposed transmitter station citation needed The accuracy of these calculations for digital TV signals is being debated 3 Antennas EditSee also UHF television broadcasting UHF vs VHF A VHF television broadcasting antenna This is a common type called a super turnstile or batwing antenna 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 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 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 Universal use EditCertain subparts of the VHF band have the same use around the world Some national uses are detailed below 50 54 MHz Amateur Radio 6 meter band 108 118 MHz Air navigation beacons VOR and Instrument Landing System localizer 118 137 MHz Airband for air traffic control AM 121 5 MHz is emergency frequency 144 146 MHz Amateur Radio 2 meter band Extends up to 148 MHz in some Regions 156 174 MHz VHF maritime mobile band for maritime two way radio on ships By country Edit A plan showing VHF use in television FM radio amateur radio marine radio and aviation Australia Edit See also Australasian television frequencies The VHF TV band in Australia was originally allocated channels 1 to 10 with channels 2 7 and 9 assigned for 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 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 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 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 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 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 4 as per its long distance reachability comparing UHF frequencies Example allocation of VHF UHF frequencies 5 Radionavigation 60 84 86 MHz Fixed Maritime Mobile 130 135 7 MHz Fixed Aeronautical radio navigation 160 190 MHz Broadcasting Aeronautical Radionavigation 255 283 5 MHz Aeronautical Radionavigation AUS 49 Maritime Radionavigation radiobeacons 73 315 325 MHzNew Zealand Edit 44 51 54 68 MHz Band I Television channels 1 3 87 5 108 MHz Band II Radio 174 230 MHz Band III Television channels 4 11 Until 2013 the four main Free to Air TV stations in New Zealand used 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 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 6 Refer to Australasian television frequencies for more information United Kingdom Edit This section does not cite any sources Please help improve this section by adding citations to reliable sources Unsourced material may be challenged and removed August 2016 Learn how and when to remove this template message British television originally used VHF band I and band III Television on VHF 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 60s 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 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 United States and Canada Edit Frequency assignments between US and Canadian users are closely coordinated since much of 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 30 49 6 MHz Licensed 2 way land mobile communication with various sub bands a 30 88 MHz Military VHF FM including SINCGARS 43 50 MHz Cordless telephones 49 MHz FM walkie talkies and radio controlled toys and mixed 2 way mobile communication The FM broadcast band originally operated here 42 50 MHz before it was moved to 88 108 MHz 50 54 MHz Amateur radio 6 meter band 50 800 51 MHz Radio controlled aircraft on ten fixed frequencies at 20 kHz spacing with an FCC Amateur Radio Service license flown under FCC Part 97 rule 97 215 7 54 88 MHz known as Band I internationally some DTV stations will appear here See North American broadcast television frequencies 54 72 MHz TV channels 2 4 VHF Lo 72 76 MHz Radio controlled models industrial remote control and other devices Model aircraft operate on 72 MHz while surface models operate on 75 MHz in the US and Canada air navigation beacons 74 8 75 2 MHz 76 88 MHz TV channels 5 6 VHF Lo 87 5 108 MHz FM radio broadcasting 87 9 91 9 non commercial 92 108 commercial in the United States known as Band II internationally 108 118 MHz Air navigation beacons VOR 118 137 MHz Airband for air traffic control AM 121 5 MHz is an emergency frequency 137 138 MHz Space research space operations meteorological satellite 8 138 144 MHz Land mobile auxiliary civil services satellite space research and other miscellaneous services 144 148 MHz Amateur radio 2 meter band 148 150 MHz Land mobile fixed satellite 150 156 MHz VHF business band public safety the unlicensed Multi Use Radio Service MURS and other 2 way land mobile FM 156 158 MHz VHF Marine Radio 156 8 MHz Channel 16 is the maritime emergency and contact frequency 159 81 161 565 MHz railways b 159 81 160 2 are railroads in Canada only and is used by trucking companies in the U S 160 6 162 Wireless microphones and TV FM broadcast remote pickup 162 4 162 55 NOAA Weather Stations narrowband FM Weatheradio Canada Stations 174 240 MHz known as Band III internationally A number of DTV channels have begun broadcasting here especially many of the stations which were assigned to these channels for previous analog operation 174 216 MHz television channels 7 13 VHF Hi 174 216 MHz professional wireless microphones low power certain exact frequencies only 216 222 MHz land mobile fixed maritime mobile 8 222 225 MHz 1 25 meters US Canada 219 220 222 225 MHz amateur radio 225 MHz and above UHF Military aircraft radio 243 MHz is an emergency frequency 225 400 MHz AM including HAVE QUICK dGPS RTCM 104 Cable television though not transmitted aerially uses a spectrum of frequencies overlapping VHF 9 VHF television Edit 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 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 10 Channels 14 19 later appeared on the UHF band while channel 1 remains unused 87 5 87 9 MHz Edit 87 5 87 9 MHz is a radio frequency 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 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 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 Unlicensed operation EditIn some countries particularly the United States and Canada limited low power license free operation 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 11 See also EditMarine VHF radio TV radio List of oldest radio stations Apex radio band FM broadcast band Moving image formats Polar mesosphere summer echoes Television channel frequencies Knife edge effect Instrument Landing System VHF omnidirectional range High frequency Low frequency Extremely low frequency Ultra low frequencyNotes Edit The 42 MHz Segment is still in current use by the California Highway Patrol New Jersey State Police Tennessee Highway Patrol and other state law enforcement agencies The 160 and 161 areas are Association of American Railroads AAR 99 channel railroad radios issued to the railroad For example AAR 21 is 160 425 MHz and that is issued to Tennessee Valley Railroad Museum as well as other railroads that want AAR Channel 21 References Edit Rec ITU R V 431 7 Nomenclature of the frequency and wavelength bands used in telecommunications PDF ITU Archived from the original PDF on 31 October 2013 Retrieved 20 February 2013 Seybold John S 2005 Introduction to RF Propagation John Wiley and Sons pp 9 10 ISBN 978 0471743682 Grotticelli Michael 2009 06 22 DTV Transition Not So Smooth in Some Markets Broadcast Engineering Archived from the original on June 28 2009 Retrieved 2009 06 24 Marine VHF radio ACMA Australian radiofrequency spectrum plan Planning ACMA Going Digital When is my area going digital goingdigital co nz Ministry for Culture and Heritage Archived from the original on 17 October 2011 Retrieved 20 October 2011 1 a b Canadian Table of Frequency Allocations 9 kHz 275 GHz 2005 revised February 2007 ed Industry Canada February 2007 pp 29 30 Cable TV Channel Frequencies www jneuhaus com Archived from the original on 23 August 2017 Retrieved 27 April 2018 What Ever Happened to Channel 1 tech notes tv Tech Notes Table 1 Archived from the original on 17 March 2017 Retrieved 27 April 2018 Change to the law to allow the use of low power FM transmitters for MP3 players Ofcom 23 November 2006 Archived from the original on 7 August 2011 Retrieved 2 October 2012 Retrieved from https en wikipedia org w index php title Very high frequency amp oldid 1050554850, wikipedia, 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