NationMaster - Encyclopedia: Amateur television

Amateur television (ATV) is the hobby of transmitting broadcast-quality video and audio over radio waves allocated for amateur radio using the broadcast standards of NTSC in North America and Japan, and PAL or SECAM in Europe and elsewhere, using the full refresh rates of those standards. It also includes the study of building of such transmitters and receivers and the propagation between these two. ATV is an extension of amateur radio. It is also called HAM TV or Fast Scan TV (FSTV). Ham operators are also allowed to transmit Slow Scan TV (SSTV) which is similar to video facsimile. SSTV may be transmitted within the voice segments of all ham radio frequency bands except 30 meters (28 - 29.7 MHz), though it is used primarily below 28 MHz. Image File history File links Broom_icon. ... A hobby is a spare-time recreational pursuit. ... Broadcasting is the distribution of audio and/or video signals which transmit programs to an audience. ... For the Talib Kweli album Quality (album) Quality can refer to a. ... For other uses, see Video (disambiguation). ... Sound reproduction is the electrical or mechanical re-creation and/or amplification of sound, often as music. ... Surface waves in water This article is about waves in the most general scientific sense. ... Amateur radio station with modern solid-state transceiver featuring LCD and DSP capabilities Amateur radio, often called ham radio, is both a hobby and a service that uses various types of radio communications equipment to communicate with other radio amateurs for public service, recreation and self-training. ... NTSC is the analog television system in use in Canada, Japan, Mexico, the Philippines, South Korea, Taiwan, the United States, and some other countries, mostly in the Americas (see map). ... North America North America is a continent[1] in the Earths northern hemisphere and (chiefly) western hemisphere. ... For other uses, see PAL (disambiguation). ... SECAM, also written SÃ‰CAM (SÃ©quentiel couleur Ã mÃ©moire, French for Sequential Color with Memory), is an analog color television system first used in France. ... For other uses, see Europe (disambiguation). ... The refresh rate (or vertical refresh rate, vertical scan rate for CRTs) is the number of times in a second that a display is illuminated. ... Antenna tower of Crystal Palace transmitter, London A transmitter (sometimes abbreviated XMTR) is an electronic device which with the aid of an antenna propagates an electromagnetic signal such as radio, television, or other telecommunications. ... In radio terminology, a receiver is an electronic circuit that receives a radio signal from an antenna and decodes the signal for use as sound, pictures, navigational-position information, etc. ... Radio propagation is a term used to explain how radio waves behave when they are transmitted, or are propagated from one point on the Earth to another. ... Amateur radio station with modern solid-state transceiver featuring LCD and DSP capabilities Amateur radio, often called ham radio, is both a hobby and a service that uses various types of radio communications equipment to communicate with other radio amateurs for public service, recreation and self-training. ... Slow-scan television (SSTV) is used by amateur radio operators, to transmit and receive static pictures in monochrome (black & white) or colour. ...

North American context

In North America, transmissions are typically sent from repeaters on four UHF channels below the UHF TV broadcast band (air channels 14 to 69) (between channels 13 and 14, in the 70 cm ham band). These can be received on a cable-ready NTSC-format TV or set-top box tuned to cable channels 57 to 60 (420-444 MHz). Individual channels (with center frequency for video and audio) are: North America North America is a continent[1] in the Earths northern hemisphere and (chiefly) western hemisphere. ... In communications, transmission is the act of transmitting electrical messages (and the associated phenonomena of radiant energy that pass through media). ... For other uses, see Repeater (disambiguation). ... This article is about the radio frequency. ... Channel, in communications (sometimes called communications channel), refers to the medium used to convey information from a sender (or transmitter) to a receiver. ... This article does not cite any references or sources. ... Coaxial cable is often used to transmit cable television into the house. ... NTSC is the analog television system in use in Canada, Japan, Mexico, the Philippines, South Korea, Taiwan, the United States, and some other countries, mostly in the Americas (see map). ... See TV (disambiguation) for other uses and Television (band) for the rock band European networks National In much of Europe television broadcasting has historically been state dominated, rather than commercially organised, although commercial stations have grown in number recently. ... A set-top box (STB) or set-top unit (STU) is a device that connects to a television and an external source of signal, turning the signal into content which is then displayed on the television screen. ... MegaHertz (MHz) is the name given to one million (106) Hertz, a measure of frequency. ... The frequency axis of this symbolic diagram would be logarithmically scaled. ... For other uses, see Video (disambiguation). ... Sound reproduction is the electrical or mechanical re-creation and/or amplification of sound, often as music. ...

The other microwave amateur radio bands also have ATV usage with vestigal side band (North American analog TV broadcast modulation standard) on 919.25 MHz, 1241.25 MHz, 1253.25, MHz, 1277.25 MHz and 1289.25 MHz usually for cross band ATV repeater outputs. 1265 MHz is a wider channel (10 MHz) for AM or FM ATV. Some areas in north America use 1255 MHz FM.

Most of the FM ATV is on 2441.5 MHz with 6.0 MHz audio subcarrier and 4 MHz deviation. ATV links are on 2417.5 MHz, 3GHz and 5 GHz bands have links in some areas. 10.4 GHz is a wideband FM and used in some ATV repeater inputs.

Amateur TV Network (ATN) has many linked repeaters in the southwest and in other states as well, see www.atn-tv.org for details. The distance record for ATV is between Hawaii and California on 434 MHz.

European context

In Europe, which generally has a narrower UHF allocation than the USA, the majority of amateur television operation is currently FM on 1.2GHz and above. The frequencies in use depend on national permissions. In most of mainland Europe, the most common frequency is 1255MHz. Other bands commonly used for ATV are the 13cm (~2.3-2.45GHz) and 3cm (~10GHz) bands, although ATV is used on most of the microwave bands. For other uses, see Europe (disambiguation). ... Ultra high frequency (UHF) designates a range (band) of electromagnetic waves whose frequency is between 300 MHz and 3. ... The abbreviations FM, Fm, and fm may refer to: Electrical engineering Frequency modulation (FM) and its most common applications: FM broadcasting, used primarily to broadcast music and speech at VHF frequencies FM synthesis, a sound-generation technique popularized by early digital synthesizers Science Femtometre (fm), an SI measure of length...

In several countries crossband repeaters are used, with AM inputs on 430 MHz and FM outputs on 1255 MHz, others have FM-ATV inputs on 13 cm and outputs on 3 cm. For other uses, see Repeater (disambiguation). ... Amplitude modulation (AM) is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. ... The abbreviations FM, Fm, and fm may refer to: Electrical engineering Frequency modulation (FM) and its most common applications: FM broadcasting, used primarily to broadcast music and speech at VHF frequencies FM synthesis, a sound-generation technique popularized by early digital synthesizers Science Femtometre (fm), an SI measure of length...

In the United Kingdom, much activity occurs using in-band repeaters. These generally have an input of 1248, 1249 or 1255MHz and typically output at 1308, 1312 or 1316 MHz, although other frequencies are also used. Simplex operation ocurs on these or other frequencies chosen to avoid interference with other users of the band, e.g. 1285MHz. In telecommunications, in-band signaling is the sending of metadata and control information in the same band, on the same channel, as used for data. ... For other uses, see Repeater (disambiguation). ... A 3-simplex or tetrahedron In geometry, a simplex (plural simplexes or simplices) or n-simplex is an n-dimensional analogue of a triangle. ...

Recent experiments have been done with digital modes following widely-adopted DVB-S and DVB-T standards. Several repeaters, e.g. GB3HV have had digital TV input and output capabilities for years, also in Germany, see [2]. Technical details of one development by a combined radio amateur/university branch effort at [3] In the scientific method, an experiment (Latin: ex- periri, of (or from) trying) is a set of observations performed in the context of solving a particular problem or question, to support or falsify a hypothesis or research concerning phenomena. ... Digital television (DTV) is a telecommunication system for broadcasting and receiving moving pictures and sound by means of digital signals, in contrast to analog signals used by analog (traditional) TV. DTV uses digital modulation data, which is digitally compressed and requires decoding by a specially designed television set, or a... DVB, short for Digital Video Broadcasting, is a suite of internationally accepted, open standards for digital television maintained by the DVB Project, an industry consortium with more than 300 members, and published by a Joint Technical Committee (JTC) of European Telecommunications Standards Institute (ETSI), European Committee for Electrotechnical Standardization (CENELEC... DVB-T stands for Digital Video Broadcasting - Terrestrial and it is the DVB European consortium standard for the broadcast transmission of digital terrestrial television. ...

Transmission standards

Typically frequency modulated TV is used on frequencies above 1200 MHz (1.2 GHz), where there is enough bandwidth for such wideband transmissions. This is often used as a repeater's input frequency, with output being standard VSB on the four channels listed above. Frequency modulation (FM) is a form of modulation which represents information as variations in the instantaneous frequency of a carrier wave. ... TV redirects here. ... This article is about the SI unit of frequency. ... Bandwidth is the difference between the upper and lower cutoff frequencies of, for example, a filter, a communication channel, or a signal spectrum, and is typically measured in hertz. ... For the automotive term, see Wideband (automotive). ... In telecommunications, transmission is the act of transmitting electrical messages (and the associated phenomena of radiant energy that passes through media). ... For other uses, see Frequency (disambiguation). ... Single-sideband modulation (SSB) is a refinement of the technique of amplitude modulation designed to be more efficient in its use of electrical power and bandwidth. ...

The abbreviations FM, Fm, and fm may refer to: Electrical engineering Frequency modulation (FM) and its most common applications: FM broadcasting, used primarily to broadcast music and speech at VHF frequencies FM synthesis, a sound-generation technique popularized by early digital synthesizers Science Femtometre (fm), an SI measure of length... Phase-shift keying (PSK) is a digital modulation scheme that conveys data by changing, or modulating, the phase of a reference signal (the carrier wave). ...

Permissible content

From 1968 to about 2004 amateur TV provided behind-the-scenes co-ordination for the annual New Year's Day Tournament of Roses Parade in Pasadena CA. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ...

HAM TV - as it is also called - provides video co-ordination of many public service events and, along with traditional amateur radio, provides much needed "eyes" in natural disasters.

U.S. stations often retransmit NASA TV while they are not in use, especially if there is currently a Space Shuttle mission. NASA TV (originally NASA Select) is the television network of the U.S. space agency, NASA. NASA TV is broadcast by satellite, and also simulcast over the Internet. ... This article is about the space vehicle. ... Space exploration is the physical exploration of outer space, both by human spaceflights and by robotic spacecraft. ...

In Melbourne, Australia, Gary VK3KHB retransmits the audio of the local VK3EKH Astronomy Net on 80 metres and adds his own graphics. This occurs each Friday at 10.00 P.M. on the VK3RTV Amateur repeater.

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North American context

European context

Transmission standards

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See also

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European context

Transmission standards

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See also

North American context