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154-562: A cable channel (sometimes known as a cable network ) is a television network available via cable television. Many of the same channels are distributed through satellite television . Alternative terms include non-broadcast channel or programming service , the latter being mainly used in legal contexts. The abbreviation CATV is used in the US for cable television and originally stood for community antenna television , from cable television's origins in 1948; in areas where over-the-air TV reception

308-583: A coordinate plane used in geometry, X increases as one travels east and Y increases as one travels north. The upper two tags are specific to the sub transmission section of the pole; the first refers to the route number, the second to the specific pole along the route. However, not all power lines follow the road. In the British region of East Anglia , EDF Energy Networks often add the Ordnance Survey Grid Reference coordinates of

462-489: A low-noise amplifier (LNA) connected to the feedhorn at the focal point of the dish. The amplified signal, still at the higher microwave frequencies, had to be fed via very expensive low-loss 50-ohm impedance gas filled hardline coaxial cable with relatively complex N-connectors to an indoor receiver or, in other designs, a downconverter (a mixer and a voltage-tuned oscillator with some filter circuitry) for downconversion to an intermediate frequency. The channel selection

616-446: A transmission pole , telephone pole , telecommunication pole , power pole , hydro pole , telegraph pole , or telegraph post , is a column or post, usually made out of wood or aluminum alloy , used to support overhead power lines and various other public utilities, such as electrical cable , fiber optic cable , and related equipment such as transformers and street lights while depending on its application. A Stobie pole

770-434: A "static line" or a "neutral", suspended above them. The OGW acts like a lightning rod, providing a low resistance path to ground thus protecting the phase conductors from lightning. Distribution lines use two systems, either grounded-wye ("Y" on electrical schematics ) or delta (Greek letter "Δ" on electrical schematics). A delta system requires only a conductor for each of the three phases. A grounded-wye system requires

924-477: A DBS service, but are received in approximately 18 million homes, as well as in any home using the Sky Deutschland commercial DBS system. All German analogue satellite broadcasts ceased on 30 April 2012. The United Kingdom has approximately 160 digital channels (including the regional variations of BBC channels, ITV channels, Channel 4 and Channel 5 ) that are broadcast without encryption from

1078-518: A built-in television tuner . Satellite television provides a wide range of channels and services. It is usually the only television available in many remote geographic areas without terrestrial television or cable television service. Different receivers are required for the two types. Some transmissions and channels are unencrypted and therefore free-to-air , while many other channels are transmitted with encryption. Free-to-view channels are encrypted but not charged-for, while pay television requires

1232-697: A commercial basis. With Charles Wheatstone he invented the Cooke and Wheatstone telegraph and founded the world's first telegraph company, the Electric Telegraph Company . Telegraph poles were first used on the Great Western Railway in 1843 when the Cooke and Wheatstone telegraph line was extended to Slough . The line had previously used buried cables but that system had proved troublesome with failing insulation. In Britain,

1386-405: A dedicated analog circuit-switched service. Other advantages include better voice quality and integration to a Voice over Internet Protocol (VoIP) network providing cheap or unlimited nationwide and international calling. In many cases, digital cable telephone service is separate from cable modem service being offered by many cable companies and does not rely on Internet Protocol (IP) traffic or

1540-540: A form of visual pollution . Many lines are placed underground for this reason, in places of high population density or scenic beauty that justify the expense. Architects design some pylons to be pretty, thus avoiding visual pollution . Some chemicals used to preserve wood poles including creosote and pentachlorophenol are toxic and have been found in the environment . The considerable improvement in weathering resistance offered by creosote infusion has long-term drawbacks. In recent years, concerns have been raised about

1694-430: A fourth conductor, the neutral , whose source is the center of the "Y" and is grounded. However, "spur lines" branching off the main line to provide power to side streets often carry only one or two phase wires, plus the neutral. A wide range of standard distribution voltages are used, from 2,400 V to 34,500 V. On poles near a service drop , there is a pole-mounted step-down distribution transformer to transform

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1848-543: A high elevation. At the outset, cable systems only served smaller communities without television stations of their own, and which could not easily receive signals from stations in cities because of distance or hilly terrain. In Canada, however, communities with their own signals were fertile cable markets, as viewers wanted to receive American signals. Rarely, as in the college town of Alfred, New York , U.S. cable systems retransmitted Canadian channels. Although early ( VHF ) television receivers could receive 12 channels (2–13),

2002-466: A higher rate. At the local headend, the feed signals from the individual television channels are received by dish antennas from communication satellites . Additional local channels, such as local broadcast television stations, educational channels from local colleges, and community access channels devoted to local governments ( PEG channels) are usually included on the cable service. Commercial advertisements for local business are also inserted in

2156-460: A lightning arrester) may also be installed between the line (ahead of the cutout) and the ground wire for lightning protection. The purpose of the device is to conduct extremely high voltages present on the line directly to ground. If uninsulated conductors touch due to wind or fallen trees, the resultant sparks can start wildfires . To reduce this problem, aerial bundled conductors are being introduced. The communications cables are attached below

2310-947: A line along the Great Western Railway . Utility poles were first used in the mid-19th century in America with telegraph systems, starting with Samuel Morse , who attempted to bury a line between Baltimore and Washington, D.C. , but moved it above ground when this system proved faulty. Today, underground distribution lines are increasingly used as an alternative to utility poles in residential neighborhoods, due to poles' perceived ugliness, as well as safety concerns in areas with large amounts of snow or ice build up. Utility poles are commonly used to carry two types of electric power lines : distribution lines (or "feeders") and sub transmission lines . Distribution lines carry power from local substations to customers. They generally carry voltages from 4.6 to 33 kilovolts (kV) for distances up to 30 mi (50 km), and include transformers to step

2464-405: A local VHF television station broadcast. Local broadcast channels were not usable for signals deemed to be a priority, but technology allowed low-priority signals to be placed on such channels by synchronizing their blanking intervals . TVs were unable to reconcile these blanking intervals and the slight changes due to travel through a medium, causing ghosting . The bandwidth of the amplifiers also

2618-463: A microwave-based system, may be used instead. Coaxial cables are capable of bi-directional carriage of signals as well as the transmission of large amounts of data . Cable television signals use only a portion of the bandwidth available over coaxial lines. This leaves plenty of space available for other digital services such as cable internet , cable telephony and wireless services, using both unlicensed and licensed spectra. Broadband internet access

2772-580: A normal parabolic satellite antenna means it can only receive signals from a single satellite at a time. Simulsat or the Vertex-RSI TORUS, is a quasi-parabolic satellite earthstation antenna that is capable of receiving satellite transmissions from 35 or more C - and K u -band satellites simultaneously. In 1945 British science fiction writer Arthur C. Clarke proposed a worldwide communications system which would function by means of three satellites equally spaced apart in earth orbit. This

2926-774: A number of years from the early 1980s one is called the trident they are usually used on short sections, though the line from Melbourne, Cambs to near Buntingford, Herts is quite long. The conductors on these are bare metal connected to the posts by insulators. Wood poles can also be used for low voltage distribution to customers. Today, utility poles may hold much more than the uninsulated copper wire that they originally supported. Thicker cables holding many twisted pair , coaxial cable , or even fibre-optic , may be carried. Simple analogue repeaters or other outside plant equipment have long been mounted against poles, and often new digital equipment for multiplexing /demultiplexing or digital repeaters may now be seen. In many places, as seen in

3080-516: A pole's brand is the manufacturer's name or logo at the top with a two-digit date beneath (sometimes preceded by a month). Below the date is a two-character wood species abbreviation and one- to three-character preservative. Some wood species may be marked "SP" for southern pine, "WC" for western cedar, or "DF" for Douglas fir. Common preservative abbreviations are "C" for creosote , "P" for pentachlorophenol , and "SK" for chromated copper arsenate (originally referred to salts type K). The next line of

3234-564: A rarity, found in an ever-dwindling number of markets. Analog television sets are accommodated, their tuners mostly obsolete and dependent entirely on the set-top box. Cable television is mostly available in North America , Europe , Australia , Asia and South America . Cable television has had little success in Africa , as it is not cost-effective to lay cables in sparsely populated areas. Multichannel multipoint distribution service ,

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3388-454: A receiver box. The cable company will provide set-top boxes based on the level of service a customer purchases, from basic set-top boxes with a standard-definition picture connected through the standard coaxial connection on the TV, to high-definition wireless digital video recorder (DVR) receivers connected via HDMI or component . Older analog television sets are cable ready and can receive

3542-414: A rooftop parabolic receiving dish (" satellite dish "), which reflects the weak signal to the dish's focal point. Mounted on brackets at the dish's focal point is a feedhorn which passes the signals through a waveguide to a device called a low-noise block converter (LNB) or low noise converter (LNC) attached to the horn. The LNB amplifies the weak signals, filters the block of frequencies in which

3696-649: A series of Soviet geostationary satellites to carry direct-to-home television, Ekran 1, was launched on 26 October 1976. It used a 714 MHz UHF downlink frequency so that the transmissions could be received with existing UHF television technology rather than microwave technology. The satellite television industry developed in the US from the cable television industry as communication satellites were being used to distribute television programming to remote cable television headends . Home Box Office (HBO), Turner Broadcasting System (TBS), and Christian Broadcasting Network (CBN, later The Family Channel ) were among

3850-765: A series of signal amplifiers and line extenders. These devices carry the signal to customers via passive RF devices called taps. The very first cable networks were operated locally, notably in 1936 by Rediffusion in London in the United Kingdom and the same year in Berlin in Germany, notably for the Olympic Games , and from 1948 onwards in the United States and Switzerland. This type of local cable network

4004-487: A single dish) pointing to different satellites. A common solution for consumers wanting to access multiple satellites is to deploy a single dish with a single LNB and to rotate the dish using an electric motor. The axis of rotation has to be set up in the north–south direction and, depending on the geographical location of the dish, have a specific vertical tilt. Set up properly the motorized dish when turned will sweep across all possible positions for satellites lined up along

4158-445: A smaller dish antenna because of the higher power transmissions and greater antenna gain. TVRO systems tend to use larger rather than smaller satellite dish antennas, since it is more likely that the owner of a TVRO system would have a C-band -only setup rather than a K u band -only setup. Additional receiver boxes allow for different types of digital satellite signal reception, such as DVB/MPEG-2 and 4DTV . The narrow beam width of

4312-417: A special telephone interface at the customer's premises that converts the analog signals from the customer's in-home wiring into a digital signal, which is then sent on the local loop (replacing the analog last mile , or plain old telephone service (POTS) to the company's switching center, where it is connected to the public switched telephone network ( PSTN ). The biggest obstacle to cable telephone service

4466-402: A special type of LNB. There are also LNBs available with a multi-switch already integrated. This problem becomes more complicated when several receivers use several dishes or several LNBs mounted in a single dish are aimed at different satellites. The set-top box selects the channel desired by the user by filtering that channel from the multiple channels received from the satellite, converts

4620-420: A specific frequency range, so as to be received by one of the transponders tuned to that frequency range aboard that satellite. The transponder then converts the signals to K u band , a process known as "translation," and transmits them back to earth to be received by home satellite stations. The downlinked satellite signal, weaker after traveling the great distance (see path loss ), is collected by using

4774-412: A tracking system to turn to follow a moving satellite. A few satellite TV systems use satellites in a Molniya orbit , a highly elliptical orbit with inclination of +/-63.4 degrees and an orbital period of about twelve hours. Satellite television, like other communications relayed by satellite, starts with a transmitting antenna located at an uplink facility. Uplink facilities transmit the signal to

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4928-536: A transponder is transmitting at and on what polarisation it is using, the satellite receiver has to switch the LNB into one of four different modes in order to receive a specific desired program on a specific transponder. The receiver uses the DiSEqC protocol to control the LNB mode, which handles this. If several satellite receivers are to be attached to a single dish a so-called multiswitch must be used in conjunction with

5082-457: A wider frequency range of 2–2150 MHz. The satellite receiver or set-top box demodulates and converts the signals to the desired form (outputs for television, audio, data, etc.). Often, the receiver includes the capability to selectively unscramble or decrypt the received signal to provide premium services to some subscribers; the receiver is then called an integrated receiver/decoder or IRD. Low-loss cable (e.g. RG-6 , RG-11 , etc.)

5236-769: Is a multi-purpose pole made of two steel joists held apart by a slab of concrete in the middle, generally found in South Australia . Electrical wires and cables are routed overhead on utility poles as an inexpensive way to keep them insulated from the ground and out of the way of people and vehicles. Utility poles can be made of wood, metal, concrete, or composites like fiberglass . They are used for two different types of power lines: sub transmission lines , which carry higher voltage power between substations, and distribution lines , which distribute lower voltage power to customers. The first poles were used in 1843 by telegraph pioneer William Fothergill Cooke , who used them on

5390-505: Is a service that delivers television programming to viewers by relaying it from a communications satellite orbiting the Earth directly to the viewer's location. The signals are received via an outdoor parabolic antenna commonly referred to as a satellite dish and a low-noise block downconverter . A satellite receiver decodes the desired television program for viewing on a television set . Receivers can be external set-top boxes , or

5544-422: Is achieved over coaxial cable by using cable modems to convert the network data into a type of digital signal that can be transferred over coaxial cable. One problem with some cable systems is the older amplifiers placed along the cable routes are unidirectional thus in order to allow for uploading of data the customer would need to use an analog telephone modem to provide for the upstream connection. This limited

5698-419: Is attached to the side of the first and runs at an angle to the ground. If there is no space for a lateral support, a stronger pole, e.g. a construction of concrete or iron, is used. The system of suspending telegraph wires from poles with ceramic insulators was invented and patented by British telegraph pioneer William Fothergill Cooke . Cooke was the driving force in establishing the electrical telegraph on

5852-414: Is because the LNB is translating two different circular polarizations (right-hand and left-hand) and, in the case of K-band, two different frequency bands (lower and upper) to the same frequency range on the cable. Depending on which frequency and polarization a transponder is using, the satellite receiver has to switch the LNB into one of four different modes in order to receive a specific "channel". This

6006-433: Is developing inspection, maintenance, and prevention procedures similar to those used on wood utility poles to identify and prevent decay. British Telecom posts are usually marked with the following information: The date on the pole is applied by the manufacturer and refers to the date the pole was "preserved" (treated to withstand the elements). In the United States, utility poles are marked with information concerning

6160-441: Is even more adversely affected by ice crystals in thunder clouds. On occasion, sun outage will occur when the sun lines up directly behind the geostationary satellite to which the receiving antenna is pointed. The downlink satellite signal, quite weak after traveling the great distance (see path loss ), is collected with a parabolic receiving dish, which reflects the weak signal to the dish's focal point. Mounted on brackets at

6314-425: Is handled by the receiver using the DiSEqC protocol to control the LNB mode. If several satellite receivers are to be attached to a single dish, a so-called multiswitch will have to be used in conjunction with a special type of LNB. There are also LNBs available with a multi-switch already integrated. This problem becomes more complicated when several receivers are to use several dishes (or several LNBs mounted in

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6468-773: Is referred to as baseband . This baseband comprises the video signal and the audio subcarrier(s). The audio subcarrier is further demodulated to provide a raw audio signal. Later signals were digitized television signals or multiplex of signals, typically QPSK . In general, digital television, including that transmitted via satellites, is based on open standards such as MPEG and DVB-S / DVB-S2 or ISDB-S . The conditional access encryption/scrambling methods include NDS , BISS , Conax , Digicipher , Irdeto, Cryptoworks , DG Crypt , Beta digital , SECA Mediaguard , Logiways , Nagravision , PowerVu , Viaccess , Videocipher , and VideoGuard . Many conditional access systems have been compromised. An event called sun outage occurs when

6622-540: Is the most significant cause of pole deterioration in the U.S. Other common utility pole materials are aluminum, steel and concrete, with composites (such as fiberglass ) also becoming more prevalent. One particular patented utility pole variant used in Australia is the Stobie pole , made up of two vertical steel posts with a slab of concrete between them. On poles carrying both electrical and communications wiring,

6776-427: Is the most widely used species in the United States; however, many species of long straight trees are used to make utility poles, including Douglas fir , jack pine , lodgepole pine , western red cedar , and Pacific silver fir . Traditionally, the preservative used was creosote , but due to environmental concerns, alternatives such as pentachlorophenol , copper naphthenate and borates are becoming widespread in

6930-482: Is the need for nearly 100% reliable service for emergency calls. One of the standards available for digital cable telephony, PacketCable , seems to be the most promising and able to work with the quality of service (QOS) demands of traditional analog plain old telephone service (POTS) service. The biggest advantage to digital cable telephone service is similar to the advantage of digital cable, namely that data can be compressed, resulting in much less bandwidth used than

7084-425: Is the only remaining satellite broadcasting in analog signals. The satellites used for broadcasting television are usually in a geostationary orbit 36,000 km (22,000 mi) above the earth's equator . The advantage of this orbit is that the satellite's orbital period equals the rotation rate of the Earth, so the satellite appears at a fixed position in the sky. Thus the satellite dish antenna which receives

7238-468: Is used to connect the receiver to the LNBF or LNB. RG-59 is not recommended for this application as it is not technically designed to carry frequencies above 950 MHz, but may work in some circumstances, depending on the quality of the coaxial wire, signal levels, cable length, etc. A practical problem relating to home satellite reception is that an LNB can basically only handle a single receiver. This

7392-671: The Relay 1 satellite was the first satellite to transmit television signals from the US to Japan. The first geosynchronous communication satellite , Syncom 2 , was launched on 26 July 1963. The subsequent first geostationary Syncom 3 , orbiting near the International Date Line , was used to telecast the 1964 Olympic Games from Tokyo to the United States . The world's first commercial communications satellite, called Intelsat I and nicknamed "Early Bird",

7546-578: The Astra 28.2°E satellite constellation, and receivable on any DVB-S receiver (a DVB-S2 receiver is required for certain high definition television services). Most of these channels are included within the Sky EPG , and an increasing number within the Freesat EPG. India 's national broadcaster, Doordarshan , promotes a free-to-air DBS package as " DD Free Dish ", which is provided as in-fill for

7700-541: The C-band (4–8 GHz) from FSS type satellites, requiring the use of large 2–3-meter dishes. Consequently, these systems were nicknamed "big dish" systems, and were more expensive and less popular. Early systems used analog signals , but modern ones use digital signals which allow transmission of the modern television standard high-definition television , due to the significantly improved spectral efficiency of digital broadcasting. As of 2022, Star One D2 from Brazil

7854-481: The C-band frequencies and the dishes required were large; typically over 3 meters (10 ft) in diameter. Consequently, TVRO is often referred to as "big dish" or "Big Ugly Dish" (BUD) satellite television. TVRO systems were designed to receive analog and digital satellite feeds of both television or audio from both C-band and K u -band transponders on FSS -type satellites. The higher frequency K u -band systems tend to resemble DBS systems and can use

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8008-491: The DVB-C , DVB-C2 stream to IP for distribution of TV over IP network in the home. Many cable companies offer internet access through DOCSIS . In the most common system, multiple television channels (as many as 500, although this varies depending on the provider's available channel capacity) are distributed to subscriber residences through a coaxial cable , which comes from a trunkline supported on utility poles originating at

8162-591: The Gorizont communication satellites later that same year. These satellites used geostationary orbits . They were equipped with powerful on-board transponders, so the size of receiving parabolic antennas of downlink stations was reduced to 4 and 2.5 metres. On October 18, 1979, the Federal Communications Commission (FCC) began allowing people to have home satellite earth stations without a federal government license. The front cover of

8316-549: The United States Congress granted Samuel Morse $ 30,000 (equivalent to $ 981,000 in 2023) to build a 40-mile telegraph line between Baltimore , Maryland and Washington, D.C. Morse began by having a lead-sheathed cable made. After laying seven miles (11 km) underground, he tested it. He found so many faults with this system that he dug up his cable, stripped off its sheath, bought poles and strung his wires overhead. On February 7, 1844, Morse inserted

8470-588: The attack on HBO's transponder Galaxy 1 by John R. MacDougall in April 1986. One by one, all commercial channels followed HBO's lead and began scrambling their channels. The Satellite Broadcasting and Communications Association (SBCA) was founded on December 2, 1986, as the result of a merger between SPACE and the Direct Broadcast Satellite Association (DBSA). Utility pole A utility pole , commonly referred to as

8624-405: The geostationary orbit directly above the equator. The dish will then be capable of receiving any geostationary satellite that is visible at the specific location, i.e. that is above the horizon. The DiSEqC protocol has been extended to encompass commands for steering dish rotors. There are five major components in a satellite system: the programming source, the broadcast center, the satellite,

8778-616: The high band 7–13 of North American television frequencies . Some operators as in Cornwall, Ontario , used a dual distribution network with Channels 2–13 on each of the two cables. During the 1980s, United States regulations not unlike public, educational, and government access (PEG) created the beginning of cable-originated live television programming. As cable penetration increased, numerous cable-only TV stations were launched, many with their own news bureaus that could provide more immediate and more localized content than that provided by

8932-466: The intermediate frequency ranges of 950–2150 MHz to carry the signal from the LNBF at the dish down to the receiver. This allows for the transmission of UHF signals along the same span of coaxial wire at the same time. In some applications ( DirecTV AU9-S and AT-9), ranges of the lower B-band and 2250–3000 MHz, are used. Newer LNBFs in use by DirecTV, called SWM (Single Wire Multiswitch), are used to implement single cable distribution and use

9086-469: The satellite dish , and the receiver . "Direct broadcast" satellites used for transmission of satellite television signals are generally in geostationary orbit 37,000 km (23,000 mi) above the earth's equator . The reason for using this orbit is that the satellite circles the Earth at the same rate as the Earth rotates, so the satellite appears at a fixed point in the sky. Thus satellite dishes can be aimed permanently at that point, and do not need

9240-712: The telephone exchange to local customers is a thick cable lashed to a thin supporting cable, containing hundreds of twisted pair subscriber lines . Each twisted pair line provides a single telephone circuit or local loop to a customer. There may also be FOCs interconnecting telephone exchanges. Like electrical distribution lines, communication cables connect to service drops when used to provide local service to customers. Utility poles may also carry other equipment such as street lights , supports for traffic lights and overhead wires for electric trolleys , and cellular network antennas. They can also carry fixtures and decorations specific for certain holidays or events specific to

9394-496: The 10.7-12.7 GHz band, but some still transmit in the C-band (4–8 GHz), K u -band (12–18 GHz), or both. The leg of the signal path from the satellite to the receiving Earth station is called the downlink. A typical satellite has up to 32 K u -band or 24 C-band transponders, or more for K u / C hybrid satellites. Typical transponders each have a bandwidth between 27 and 50 MHz. Each geostationary C-band satellite needs to be spaced 2° longitude from

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9548-424: The 1979 Neiman-Marcus Christmas catalogue featured the first home satellite TV stations on sale for $ 36,500. The dishes were nearly 20 feet (6.1 m) in diameter and were remote controlled. The price went down by half soon after that, but there were only eight more channels. The Society for Private and Commercial Earth Stations (SPACE), an organisation which represented consumers and satellite TV system owners,

9702-491: The Internet. Traditional cable television providers and traditional telecommunication companies increasingly compete in providing voice, video and data services to residences. The combination of television, telephone and Internet access is commonly called triple play , regardless of whether CATV or telcos offer it. More than 400,000 television service subscribers. Satellite television Satellite television

9856-529: The UK, boots fitted with steel loops that go around the pole (known as "Scandinavian Climbers") are also used for climbing poles. In the US, linemen use bucket trucks for the vast majority of poles that are accessible by vehicle. The poles at the end of a straight section of utility line where the line ends or angles off in another direction are called dead-end poles in the United States. Elsewhere they may be referred to as anchor or termination poles. These must carry

10010-550: The US Department of Agriculture) for pole strength and loading. Steel utility poles are becoming more prevalent in the United States thanks to improvements in engineering and corrosion prevention coupled with lowered production costs. However, premature failure due to corrosion is a concern when compared to wood. The National Association of Corrosion Engineers Archived 2010-06-19 at the Wayback Machine or NACE

10164-591: The US most condominiums, neighborhoods, and other homeowner associations tightly restricted their use, except in areas where such restrictions were illegal. These restrictions were altered in 1986 when the Federal Communications Commission ruled all of them illegal. A municipality could require a property owner to relocate the dish if it violated other zoning restrictions, such as a setback requirement, but could not outlaw their use. The necessity of these restrictions would slowly decline as

10318-508: The US). For economic or practical reasons, such as to save space in urban areas, a distribution line is often carried on the same poles as a sub transmission line but mounted under the higher voltage lines; a practice called "underbuild". Telecommunication cables are usually carried on the same poles that support power lines; poles shared in this fashion are known as joint-use poles, but may have their own dedicated poles. The standard utility pole in

10472-419: The United Kingdom, utility poles have sets of brackets arranged in a standard pattern up the pole to act as hand and foot holds so that maintenance and repair workers can climb the pole to work on the lines. In the United States, such steps have been determined to be a public hazard and are no longer allowed on new poles. Linemen may use climbing spikes called gaffs to ascend wooden poles without steps on them. In

10626-608: The United States electricity is predominately carried on unshielded aluminum conductors wound around a solid steel core and affixed to rated insulators made from glass, ceramic, or poly. Telephone, CATV, and FOCs are generally attached directly to the pole without insulators. In the United Kingdom, much of the rural electricity distribution system is carried on wooden poles. These normally carry electricity at 11 or 33 kV (three phases) from 132 kV substations supplied from pylons to distribution substations or pole-mounted transformers. Wooden poles have been used for 132 kV for

10780-484: The United States have switched to or are in the course of switching to digital cable television since it was first introduced in the late 1990s. Most cable companies require a set-top box ( cable converter box ) or a slot on one's TV set for conditional access module cards to view their cable channels, even on newer televisions with digital cable QAM tuners, because most digital cable channels are now encrypted, or scrambled , to reduce cable service theft . A cable from

10934-487: The United States is about 35 ft (10 m) tall and is buried about 6 ft (2 m) in the ground. In order to meet clearance regulations, poles can, however, reach heights of at least 120 feet (40 meters). They are typically spaced about 125 ft (40 m) apart in urban areas, or about 300 ft (100 m) in rural areas, but distances vary widely based on terrain. Joint-use poles are usually owned by one utility, which leases space on it for other cables. In

11088-812: The United States, the National Electrical Safety Code , published by the Institute of Electrical and Electronics Engineers (IEEE) (not to be confused with the National Electrical Code published by the National Fire Protection Association [NFPA]), sets the standards for construction and maintenance of utility poles and their equipment. Most utility poles are made of wood, pressure-treated with some type of preservative for protection against rot, fungi and insects. Southern yellow pine

11242-482: The United States. In the United States, standards for wood preservative materials and wood preservation processes, along with test criteria, are set by ANSI , ASTM , and American Wood Protection Association (AWPA) specifications. Despite the preservatives, wood poles decay and have a life of approximately 25 to 50 years depending on climate and soil conditions, therefore requiring regular inspection and remedial preservative treatments. Woodpecker damage to wood poles

11396-404: The basic selection. By subscribing to additional tiers, customers could get specialty channels, movie channels, and foreign channels. Large cable companies used addressable descramblers to limit access to premium channels for customers not subscribing to higher tiers, however the above magazines often published workarounds for that technology as well. During the 1990s, the pressure to accommodate

11550-485: The bottom connected to a metal rod driven into the ground. Some countries ground every pole while others only ground every fifth pole and any pole with a transformer on it. This provides a path for leakage currents across the surface of the insulators to get to ground, preventing the current from flowing through the wooden pole which could cause a fire or shock hazard. It provides similar protection in case of flashovers and lightning strikes. A surge arrester (also called

11704-427: The brand is usually the pole's ANSI class, used to determine maximum load; this number ranges from 10 to H6 with a smaller number meaning higher strength. The pole's height (from butt to top) in 5-foot increments is usually to the right of the class separated by a hyphen, although it is not uncommon for older brands to have the height on a separate line. The pole brand is sometimes an aluminum tag nailed in place. Before

11858-563: The cable box itself, these midband channels were used for early incarnations of pay TV , e.g. The Z Channel (Los Angeles) and HBO but transmitted in the clear i.e. not scrambled as standard TV sets of the period could not pick up the signal nor could the average consumer de-tune the normal stations to be able to receive it. Once tuners that could receive select mid-band and super-band channels began to be incorporated into standard television sets, broadcasters were forced to either install scrambling circuitry or move these signals further out of

12012-429: The cable company's local distribution facility, called the headend . Many channels can be transmitted through one coaxial cable by a technique called frequency division multiplexing . At the headend, each television channel is translated to a different frequency . By giving each channel a different frequency slot on the cable, the separate television signals do not interfere with each other. At an outdoor cable box on

12166-515: The cable to send data from the customer box to the cable headend, for advanced features such as requesting pay-per-view shows or movies, cable internet access , and cable telephone service . The downstream channels occupy a band of frequencies from approximately 50 MHz to 1 GHz, while the upstream channels occupy frequencies of 5 to 42 MHz. Subscribers pay with a monthly fee. Subscribers can choose from several levels of service, with premium packages including more channels but costing

12320-465: The cables would be expensive. Another situation in which pole routes were extensively used were on the railways to link signal boxes . Traditionally, prior to around 1965, pole routes were built with open wires along non-electrical operated railways; this necessitated insulation when the wire passed over the pole, thus preventing the signal from becoming attenuated. At electrical operated railways, pole routes were usually not built as too much jamming from

12474-675: The case of no local CBS or ABC station being available – rebroadcast the programming from a nearby affiliate but fill in with its own news and other community programming to suit its own locale. Many live local programs with local interests were subsequently created all over the United States in most major television markets in the early 1980s. This evolved into today's many cable-only broadcasts of diverse programming, including cable-only produced television movies and miniseries . Cable specialty channels , starting with channels oriented to show movies and large sporting or performance events, diversified further, and narrowcasting became common. By

12628-484: The channels. The signal is then sent to the uplink where it is transmitted to the satellite. With some broadcast centers, the studios, administration and up-link are all part of the same campus. The satellite then translates and broadcasts the channels. Most systems use the DVB-S standard for transmission. With pay television services, the data stream is encrypted and requires proprietary reception equipment. While

12782-507: The chosen channel into the TV set on Channel 2, 3 or 4. Initially, UHF broadcast stations were at a disadvantage because the standard TV sets in use at the time were unable to receive their channels. With the passage of the All-Channel Receiver Act in 1964, all new television sets were required to include a UHF tuner, nonetheless, it would still take a few years for UHF stations to become competitive. Before being added to

12936-852: The city where they are located. Solar panels mounted on utility poles may power auxiliary equipment where the expense of a power line connection is unwanted. Streetlights and holiday fixtures are powered directly from secondary distribution. The primary purpose of pole attachment hardware is to secure the cable and associated aerial plant facilities to poles and to help facilitate necessary plant rearrangements. An aerial plant network requires high-quality reliable hardware to Functional performance requirements common to pole line hardware for utility poles made of wood, steel, concrete, or Fiber-Reinforced Composite (FRC) materials are contained in Telcordia GR-3174, Generic Requirements for Hardware Attachments for Utility Poles . In some countries, such as

13090-461: The company reactivates it. Some receivers are capable of decrypting the received signal itself. These receivers are called integrated receiver/decoders or IRDs. Analog television which was distributed via satellite was usually sent scrambled or unscrambled in NTSC , PAL , or SECAM television broadcast standards. The analog signal is frequency modulated and is converted from an FM signal to what

13244-547: The country's terrestrial transmission network. It is broadcast from GSAT-15 at 93.5°E and contains about 80 FTA channels. While originally launched as backhaul for their digital terrestrial television service, a large number of French channels are free-to-air on satellites at 5°W, and have recently been announced as being official in-fill for the DTT network. In North America (United States, Canada and Mexico ) there are over 80 FTA digital channels available on Galaxy 19 (with

13398-523: The dish's focal point is a device called a feedhorn or collector. The feedhorn is a section of waveguide with a flared front-end that gathers the signals at or near the focal point and conducts them to a probe or pickup connected to a low-noise block downconverter (LNB). The LNB amplifies the signals and downconverts them to a lower block of intermediate frequencies (IF), usually in the L-band . The original C-band satellite television systems used

13552-539: The dishes got smaller. Originally, all channels were broadcast in the clear (ITC) because the equipment necessary to receive the programming was too expensive for consumers. With the growing number of TVRO systems, the program providers and broadcasters had to scramble their signal and develop subscription systems. In October 1984, the U.S. Congress passed the Cable Communications Policy Act of 1984 , which gave those using TVRO systems

13706-691: The early days of satellite television reception to differentiate it from commercial satellite television uplink and downlink operations (transmit and receive). This was the primary method of satellite television transmissions before the satellite television industry shifted, with the launch of higher powered DBS satellites in the early 1990s which transmitted their signals on the K u band frequencies. Satellite television channels at that time were intended to be used by cable television networks rather than received by home viewers. Early satellite television receiver systems were largely constructed by hobbyists and engineers. These early TVRO systems operated mainly on

13860-588: The electric power distribution lines and associated equipment are mounted at the top of the pole above the communication cables, for safety. The vertical space on the pole reserved for this equipment is called the supply space . The wires themselves are usually uninsulated, and supported by insulators , commonly mounted on a horizontal beam ( crossarm ). Power is transmitted using the three-phase system, with three wires, or phases, labeled "A", "B", and "C". Sub transmission lines comprise only these 3 wires, plus sometimes an overhead ground wire (OGW), also called

14014-659: The electric power lines, in a vertical space along the pole designated the communications space . The communications space is separated from the lowest electrical conductor by the communication worker safety zone , which provides room for workers to maneuver safely while servicing the communication cables, avoiding contact with the power lines. The most common communication cables found on utility poles are copper or fibre-optic cable (FOC) for telephone lines and coaxial cable for cable television (CATV). Coaxial or optical fibre cables linking computer networks are also increasingly found on poles in urban areas. The cable linking

14168-420: The event of an overload, the fuse melts and the device pivots open to provide a visual indication of the problem. They can also be opened manually by linemen using a long insulated rod called a hot stick to disconnect the transformer from the line. The pole may be grounded with a heavy bare copper or copper-clad steel wire running down the pole, attached to the metal pin supporting each insulator, and at

14322-415: The fact that the descrambling circuitry was for a time present in these tuners, depriving the cable operator of much of their revenue, such cable-ready tuners are rarely used now – requiring a return to the set-top boxes used from the 1970s onward. The digital television transition in the United States has put all signals, broadcast and cable, into digital form, rendering analog cable television service

14476-582: The first satellite in history. The first public satellite television signals from Europe to North America were relayed via the Telstar satellite over the Atlantic ocean on 23 July 1962, although a test broadcast had taken place almost two weeks earlier on 11 July. The signals were received and broadcast in North American and European countries and watched by over 100 million. Launched in 1962,

14630-538: The first to use satellite television to deliver programming. Taylor Howard of San Andreas , California , became the first person to receive C-band satellite signals with his home-built system in 1976. In the US, PBS , a non-profit public broadcasting service, began to distribute its television programming by satellite in 1978. In 1979, Soviet engineers developed the Moskva (or Moscow ) system of broadcasting and delivering of TV signals via satellites. They launched

14784-626: The following advertisement in the Washington newspaper: "Sealed proposals will be received by the undersigned for furnishing 700 straight and sound chestnut posts with the bark on and of the following dimensions to wit: 'Each post must not be less than eight inches in diameter at the butt and tapering to five or six inches at the top. Six hundred and eighty of said posts to be 24 feet in length, and 20 of them 30 feet in length.'" In some parts of Australia, wooden poles are rapidly destroyed by termites , so metal poles must be used instead and in much of

14938-457: The growing array of offerings resulted in digital transmission that made more efficient use of the VHF signal capacity; fibre optics was common to carry signals into areas near the home, where coax could carry higher frequencies over the short remaining distance. Although for a time in the 1980s and 1990s, television receivers and VCRs were equipped to receive the mid-band and super-band channels. Due to

15092-450: The headend, the electrical signal is translated into an optical signal and sent through the fiber. The fiber trunkline goes to several distribution hubs , from which multiple fibers fan out to carry the signal to boxes called optical nodes in local communities. At the optical node, the optical signal is translated back into an electrical signal and carried by coaxial cable distribution lines on utility poles, from which cables branch out to

15246-467: The high distribution voltage to the lower secondary voltage provided to the customer. In North America , service drops provide 240/120 V split-phase power for residential and light commercial service, using cylindrical single-phase transformers. In Europe and most other countries, 230 V three phase (230Y400) service drops are used. The transformer's primary is connected to the distribution line through protective devices called fuse cutouts . In

15400-553: The illustration, providers of electricity, television, telephone, street light, traffic signal and other services share poles, either in joint ownership or by renting space to each other. In the United States, ANSI standard 05.1.2008 governs wood pole sizes and strength loading. Utilities that fall under the Rural Electrification Act must also follow the guidelines set forth in RUS Bulletin 1724E-150 (from

15554-488: The indoor receiver to the satellite television dish and LNB, and that the technology for handling the signal at L-band and UHF was far cheaper than that for handling the signal at C-band frequencies. The shift to cheaper technology from the hardline and N-connectors of the early C-band systems to the cheaper and simpler 75-ohm cable and F-connectors allowed the early satellite television receivers to use, what were in reality, modified UHF television tuners which selected

15708-551: The interior wooden poles are vulnerable to fire. The Oppenheimer pole is a collapsible wrought iron pole in three sections. It is named after Oppenheimer and Company in Germany, but they were mostly manufactured in England under license. They were used on the Australian Overland Telegraph Line built in 1872 which connected the continent north to south directly through the centre and linked to

15862-460: The jack in the wall is attached to the input of the box, and an output cable from the box is attached to the television, usually the RF-IN or composite input on older TVs. Since the set-top box only decodes the single channel that is being watched, each television in the house requires a separate box. Some unencrypted channels, usually traditional over-the-air broadcast networks, can be displayed without

16016-490: The late 1980s, cable-only signals outnumbered broadcast signals on cable systems, some of which by this time had expanded beyond 35 channels. By the mid-1980s in Canada, cable operators were allowed by the regulators to enter into distribution contracts with cable networks on their own. By the 1990s, tiers became common, with customers able to subscribe to different tiers to obtain different selections of additional channels above

16170-597: The lateral tension of the long straight sections of wire. They are usually made with heavier construction. The power lines are attached to the pole by horizontal strain insulators, either placed on crossarms (which are either doubled, tripled, or replaced with a steel crossarm, to provide more resistance to the tension forces) or attached directly to the pole itself. Dead-end and other poles that support lateral loads have guy-wires to support them. The guys always have strain insulators inserted in their length to prevent any high voltages caused by electrical faults from reaching

16324-425: The local utility poles or underground utility lines. Coaxial cable brings the signal to the customer's building through a service drop , an overhead or underground cable. If the subscriber's building does not have a cable service drop, the cable company will install one. The standard cable used in the U.S. is RG-6 , which has a 75 ohm impedance , and connects with a type F connector . The cable company's portion of

16478-425: The lower portion of the cable that is accessible by the public. In populated areas, guy wires are often encased in a yellow plastic or wood tube with reflectors attached to their lower end, so that they can be seen more easily, reducing the chance of people and animals walking into them or vehicles crashing into them. Another means of providing support for lateral loads is a push brace pole, a second shorter pole that

16632-471: The majority being ethnic or religious in nature). Other FTA satellites include AMC-4 , AMC-6 , Galaxy 18 , and Satmex 5. A company called GloryStar promotes FTA religious broadcasters on Galaxy 19 . Satellite TV has seen a decline in consumers since the 2010s due to the cord-cutting trend where people are shifting towards internet-based streaming television and free over-the-air television . The term television receive-only , or TVRO, arose during

16786-644: The manufacturer forces preservatives into the wood, until it refuses to accept more, but performance is not guaranteed. Some of these were still in service after 80 years. The building of pole lines was resisted in some urban areas in the late 19th century, and political pressure for undergrounding remains powerful in many countries. In Eastern Europe , Russia, and third-world countries, many utility poles still carry bare communication wires mounted on insulators not only along railway lines, but also along roads and sometimes even in urban areas. Errant traffic being uncommon on railways, their poles are usually less tall. In

16940-457: The manufacturer, pole height, ANSI strength class, wood species, original preservative, and year manufactured (vintage) in accordance with ANSI standard O5.1.2008. This is called branding, as it is usually burned into the surface; the resulting mark is sometimes called the "birth mark". Although the position of the brand is determined by ANSI specification, it is essentially just below "eye level" after installation. A rule of thumb for understanding

17094-417: The market. Some countries operate satellite television services which can be received for free, without paying a subscription fee. This is called free-to-air satellite television. Germany is likely the leader in free-to-air with approximately 250 digital channels (including 83 HDTV channels and various regional channels) broadcast from the Astra 19.2°E satellite constellation. These are not marketed as

17248-423: The maximum number of channels that could be broadcast in one city was 7: channels 2, 4, either 5 or 6, 7, 9, 11 and 13, as receivers at the time were unable to receive strong (local) signals on adjacent channels without distortion. (There were frequency gaps between 4 and 5, and between 6 and 7, which allowed both to be used in the same city). As equipment improved, all twelve channels could be utilized, except where

17402-451: The nearest network newscast. Such stations may use similar on-air branding as that used by the nearby broadcast network affiliate, but the fact that these stations do not broadcast over the air and are not regulated by the FCC, their call signs are meaningless. These stations evolved partially into today's over-the-air digital subchannels, where a main broadcast TV station e.g. NBC 37* would – in

17556-432: The next satellite to avoid interference; for K u the spacing can be 1°. This means that there is an upper limit of 360/2 = 180 geostationary C-band satellites or 360/1 = 360 geostationary K u -band satellites. C-band transmission is susceptible to terrestrial interference while K u -band transmission is affected by rain (as water is an excellent absorber of microwaves at this particular frequency). The latter

17710-408: The old analog cable without a set-top box. To receive digital cable channels on an analog television set, even unencrypted ones, requires a different type of box, a digital television adapter supplied by the cable company or purchased by the subscriber. Another new distribution method that takes advantage of the low cost high quality DVB distribution to residential areas, uses TV gateways to convert

17864-612: The overhead wire would occur. To accomplish this, cables were separated using spars with insulators spaced along them; in general four insulators were used per spar. Only one such pole route still exists on the UK rail network, in the highlands of Scotland. There was also a long section in place between Wymondham , Norfolk and Brandon in Suffolk , United Kingdom; however, this was de-wired and removed during March 2009. Utility poles are used by birds for nesting and to rest on. Utility poles and related structures are regarded by some to be

18018-421: The pole or substation to the name sign. In some areas, utility pole name plates may provide valuable coordinate information: a poor man's GPS . A pole route (or pole line in the US) is a telephone link or electrical power line between two or more locations by way of multiple uninsulated wires suspended between wooden utility poles. This method of link is common especially in rural areas where burying

18172-417: The practice of branding, many utilities would set a 2- to 4-digit date nail into the pole upon installation. The use of date nails went out of favor during World War II due to war shortages but is still used by a few utilities. These nails are considered valuable to collectors, with older dates being more valuable, and unique markings such as the utilities' name also increasing the value. However, regardless of

18326-504: The programming at the headend (the individual channels, which are distributed nationally, also have their own nationally oriented commercials). Modern cable systems are large, with a single network and headend often serving an entire metropolitan area . Most systems use hybrid fiber-coaxial (HFC) distribution; this means the trunklines that carry the signal from the headend to local neighborhoods are optical fiber to provide greater bandwidth and also extra capacity for future expansion. At

18480-454: The programming without cost. Later, the cable operators began to carry FM radio stations, and encouraged subscribers to connect their FM stereo sets to cable. Before stereo and bilingual TV sound became common, Pay-TV channel sound was added to the FM stereo cable line-ups. About this time, operators expanded beyond the 12-channel dial to use the midband and superband VHF channels adjacent to

18634-475: The quality of the coaxial wire. The shift to more affordable technology from the 50   ohm impedance cable and N-connectors of the early C-band systems to the cheaper 75   ohm technology and F-connectors allowed the early satellite television receivers to use, what were in reality, modified UHF television tuners which selected the satellite television channel for down conversion to another lower intermediate frequency centered on 70 MHz where it

18788-476: The range of reception for early cable-ready TVs and VCRs. However, once consumer sets had the ability to receive all 181 FCC allocated channels, premium broadcasters were left with no choice but to scramble. The descrambling circuitry was often published in electronics hobby magazines such as Popular Science and Popular Electronics allowing anybody with anything more than a rudimentary knowledge of broadcast electronics to be able to build their own and receive

18942-493: The residence using cheap coaxial cable . To transport the signal into the house at its original K u band microwave frequency would require an expensive waveguide , a metal pipe to carry the radio waves. The cable connecting the receiver to the LNB are of the low loss type RG-6 , quad shield RG-6, or RG-11. RG-59 is not recommended for this application as it is not technically designed to carry frequencies above 950 MHz, but will work in many circumstances, depending on

19096-648: The rest of the world through a submarine cable at Darwin . The Stobie pole was invented in 1924 by James Cyril Stobie of the Adelaide Electric Supply Company and first used in South Terrace, Adelaide . One of the early Bell System lines was the Washington DC–Norfolk line which was, for the most part, square-sawn tapered poles of yellow pine probably treated to refusal with creosote . "Treated to refusal" means that

19250-466: The right to receive signals for free unless they were scrambled, and required those who did scramble to make their signals available for a reasonable fee. Since cable channels could prevent reception by big dishes, other companies had an incentive to offer competition. In January 1986, HBO began using the now-obsolete VideoCipher II system to encrypt their channels . Other channels used less secure television encryption systems. The scrambling of HBO

19404-434: The satellite over a narrow beam of microwaves , typically in the C-band frequency range due to its resistance to rain fade . Uplink satellite dishes are very large, often as much as 9 to 12 metres (30 to 40 feet) in diameter to achieve accurate aiming and increased signal strength at the satellite, to improve reliability. The uplink dish is pointed toward a specific satellite and the uplinked signals are transmitted within

19558-419: The satellite television channel for down conversion to a lower intermediate frequency centered on 70 MHz, where it was demodulated. This shift allowed the satellite television DTH industry to change from being a largely hobbyist one where only small numbers of systems costing thousands of US dollars were built, to a far more commercial one of mass production. In the United States, service providers use

19712-404: The satellite television signals are transmitted, and converts the block of frequencies to a lower frequency range in the L-band range. The signal is then passed through a coaxial cable into the residence to the satellite television receiver, a set-top box next to the television. The reason for using the LNB to do the frequency translation at the dish is so that the signal can be carried into

19866-718: The satellite's transponders drowns out reception. Direct-to-home (DTH) can either refer to the communications satellites themselves that deliver service or the actual television service. Most satellite television customers in developed television markets get their programming through a direct broadcast satellite (DBS) provider. Signals are transmitted using K u band (12 to 18 GHz) and are completely digital which means it has high picture and stereo sound quality. Programming for satellite television channels comes from multiple sources and may include live studio feeds. The broadcast center assembles and packages programming into channels for transmission and, where necessary, encrypts

20020-428: The satellite. The uplink dish is pointed toward a specific satellite and the uplinked signals are transmitted within a specific frequency range, so as to be received by one of the transponders tuned to that frequency range aboard that satellite. The transponder re-transmits the signals back to Earth at a different frequency (a process known as translation, used to avoid interference with the uplink signal), typically in

20174-603: The signal can be aimed permanently at the location of the satellite and does not have to track a moving satellite. A few systems instead use a highly elliptical orbit with inclination of +/−63.4 degrees and an orbital period of about twelve hours, known as a Molniya orbit . Satellite television, like other communications relayed by satellite, starts with a transmitting antenna located at an uplink facility. Uplink satellite dishes are very large, as much as 9 to 12 meters (30 to 40 feet) in diameter. The increased diameter results in more accurate aiming and increased signal strength at

20328-409: The signal to a lower intermediate frequency , decrypts the encrypted signal, demodulates the radio signal and sends the resulting video signal to the television through a cable. To decrypt the signal the receiver box must be "activated" by the satellite company. If the customer fails to pay their monthly bill the box is "deactivated" by a signal from the company, and the system will not work until

20482-418: The signals are typically encrypted on modern digital cable systems, and the set-top box must be activated by an activation code sent by the cable company before it will function, which is only sent after the subscriber signs up. If the subscriber fails to pay their bill, the cable company can send a signal to deactivate the subscriber's box, preventing reception. There are also usually upstream channels on

20636-403: The subscriber's residence, the company's service drop cable is connected to cables distributing the signal to different rooms in the building. At each television, the subscriber's television or a set-top box provided by the cable company translates the desired channel back to its original frequency ( baseband ), and it is displayed onscreen. Due to widespread cable theft in earlier analog systems,

20790-418: The sun lines up directly behind the satellite in the field of view of the receiving satellite dish. This happens for about a 10-minute period daily around midday, twice every year for a two-week period in the spring and fall around the equinox . During this period, the sun is within the main lobe of the dish's reception pattern, so the strong microwave noise emitted by the sun on the same frequencies used by

20944-453: The trees used for telegraph poles were either native larch or pine from Sweden and Norway. Poles in early installations were treated with tar, but these were found to last only around seven years. Later poles were treated instead with creosote or copper sulphate for the preservative. Utility poles were first used in the mid-19th century in America with telegraph systems. In 1844,

21098-417: The underlying reception technology is similar, the pay television technology is proprietary, often consisting of a conditional-access module and smart card . This measure assures satellite television providers that only authorized, paying subscribers have access to pay television content but at the same time can allow free-to-air channels to be viewed even by the people with standard equipment available in

21252-532: The upstream speed to 31.2 Kbp/s and prevented the always-on convenience broadband internet typically provides. Many large cable systems have upgraded or are upgrading their equipment to allow for bi-directional signals, thus allowing for greater upload speed and always-on convenience, though these upgrades are expensive. In North America , Australia and Europe , many cable operators have already introduced cable telephone service, which operates just like existing fixed line operators. This service involves installing

21406-471: The use of gallium arsenide FET technology enabled the use of smaller dishes. Five hundred thousand systems, some costing as little as $ 2000, were sold in the US in 1984. Dishes pointing to one satellite were even cheaper. People in areas without local broadcast stations or cable television service could obtain good-quality reception with no monthly fees. The large dishes were a subject of much consternation, as many people considered them eyesores , and in

21560-425: The value to collectors, all attachments on a utility pole are the property of the utility company, and unauthorized removal is a misdemeanor or felony. A practice in some areas is to place poles on coordinates upon a grid. The pole at right is a Delmarva Power pole located in a rural area of the state of Maryland in the United States. The lower two tags are the "X" and "Y" coordinates along said grid. Just as in

21714-433: The viewer to subscribe and pay a monthly fee to receive the programming. Modern systems signals are relayed from a communications satellite on the X band (8–12 GHz) or K u band (12–18 GHz) frequencies requiring only a small dish less than a meter in diameter. The first satellite TV systems were a now-obsolete type known as television receive-only . These systems received weaker analog signals transmitted in

21868-606: The voltage down from the primary voltage to the lower secondary voltage used by the customer. A service drop carries this lower voltage to the customer's premises. Subtransmission lines carry higher voltage power from regional substations to local substations. They usually carry 46 kV, 69 kV, or 115 kV for distances up to 60 mi (100 km). 23 kV lines are often supported on H-shaped towers made with two or three poles. Transmission lines carrying voltages of above 230 kV are usually not supported by poles, but by metal pylons (known as transmission towers in

22022-552: The wiring usually ends at a distribution box on the building exterior, and built-in cable wiring in the walls usually distributes the signal to jacks in different rooms to which televisions are connected. Multiple cables to different rooms are split off the incoming cable with a small device called a splitter . There are two standards for cable television; older analog cable, and newer digital cable which can carry data signals used by digital television receivers such as high-definition television (HDTV) equipment. All cable companies in

22176-644: Was Canada 's geostationary Anik 1 , which was launched on 9 November 1972. ATS-6 , the world's first experimental educational and direct broadcast satellite (DBS), was launched on 30 May 1974. It transmitted at 860 MHz using wideband FM modulation and had two sound channels. The transmissions were focused on the Indian subcontinent but experimenters were able to receive the signal in Western Europe using home constructed equipment that drew on UHF television design techniques already in use. The first in

22330-473: Was controlled typically by a voltage tuned oscillator with the tuning voltage being fed via a separate cable to the headend, but this design evolved. Designs for microstrip -based converters for amateur radio frequencies were adapted for the 4 GHz C-band . Central to these designs was concept of block downconversion of a range of frequencies to a lower, more easily handled IF. The advantages of using an LNB are that cheaper cable can be used to connect

22484-399: Was demodulated. An LNB can only handle a single receiver. This is due to the fact that the LNB is mapping two different circular polarisations – right hand and left hand – and in the case of the K u -band two different reception bands – lower and upper – to one and the same frequency band on the cable, and is a practical problem for home satellite reception. Depending on which frequency

22638-432: Was established in 1980. Early satellite television systems were not very popular due to their expense and large dish size. The satellite television dishes of the systems in the late 1970s and early 1980s were 10 to 16 feet (3.0 to 4.9 m) in diameter, made of fibreglass or solid aluminum or steel , and in the United States cost more than $ 5,000, sometimes as much as $ 10,000. Programming sent from ground stations

22792-530: Was launched into geosynchronous orbit on April 6, 1965. The first national network of television satellites, called Orbita , was created by the Soviet Union in October 1967, and was based on the principle of using the highly elliptical Molniya satellite for rebroadcasting and delivering of television signals to ground downlink stations. The first domestic satellite to carry television transmissions

22946-443: Was limited by distance from transmitters or mountainous terrain, large community antennas were constructed, and cable was run from them to individual homes. In 1968, 6.4% of Americans had cable television. The number increased to 7.5% in 1978. By 1988, 52.8% of all households were using cable. The number further increased to 62.4% in 1994. To receive cable television at a given location, cable distribution lines must be available on

23100-427: Was limited, meaning frequencies over 250 MHz were difficult to transmit to distant portions of the coaxial network, and UHF channels could not be used at all. To expand beyond 12 channels, non-standard midband channels had to be used, located between the FM band and Channel 7, or superband beyond Channel 13 up to about 300 MHz; these channels initially were only accessible using separate tuner boxes that sent

23254-557: Was mainly used to relay terrestrial channels in geographical areas poorly served by terrestrial television signals. Cable television began in the United States as a commercial business in 1950s. The early systems simply received weak ( broadcast ) channels, amplified them, and sent them over unshielded wires to the subscribers, limited to a community or to adjacent communities. The receiving antenna would be taller than any individual subscriber could afford, thus bringing in stronger signals; in hilly or mountainous terrain it would be placed at

23408-445: Was met with much protest from owners of big-dish systems, most of which had no other option at the time for receiving such channels, claiming that clear signals from cable channels would be difficult to receive. Eventually HBO allowed dish owners to subscribe directly to their service for $ 12.95 per month, a price equal to or higher than what cable subscribers were paying, and required a descrambler to be purchased for $ 395. This led to

23562-534: Was published in the October 1945 issue of the Wireless World magazine and won him the Franklin Institute 's Stuart Ballantine Medal in 1963. The first satellite relayed communication was achieved early on in the space age, after the first relay test was conducted by Pioneer 1 and the first radio broadcast by SCORE at the end of 1958, after at the beginning of the year Sputnik I became

23716-592: Was relayed from eighteen satellites in geostationary orbit located 22,300 miles (35,900 km) above the Earth. By 1980, satellite television was well established in the US and Europe. On 26 April 1982, the first satellite channel in the UK, Satellite Television Ltd. (later Sky One ), was launched. Its signals were transmitted from the ESA 's Orbital Test Satellites . Between 1981 and 1985, TVRO systems' sales rates increased as prices fell. Advances in receiver technology and

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