Digital television adapter - AbsoluteAstronomy.com

A digital television adapter (DTA), or digital-to-analog converter
Digital-to-analog converter
In electronics, a digital-to-analog converter is a device that converts a digital code to an analog signal . An analog-to-digital converter performs the reverse operation...

[set-top box
Set-top box
A set-top box or set-top unit is an information appliance device that generally contains a tuner and connects to a television set and an external source of signal, turning the signal into content which is then displayed on the television screen or other display device.-History:Before the...

], or commonly known as a converter box, it is a television tuner that receives a digital television

Digital television

Digital television is the transmission of audio and video by digital signals, in contrast to the analog signals used by analog TV...

(DTV) transmission

Transmission (telecommunications)

Transmission, in telecommunications, is the process of sending, propagating and receiving an analogue or digital information signal over a physical point-to-point or point-to-multipoint transmission medium, either wired, optical fiber or wireless...

, and converts the digital signal

Digital signal

A digital signal is a physical signal that is a representation of a sequence of discrete values , for example of an arbitrary bit stream, or of a digitized analog signal...

into an analog signal

Analog signal

An analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are...

that can be received and displayed on an analog television

Analog television

Analog television is the analog transmission that involves the broadcasting of encoded analog audio and analog video signal: one in which the message conveyed by the broadcast signal is a function of deliberate variations in the amplitude and/or frequency of the signal...

set. It may refer to over-the-air broadcast television signals received by an television antenna

Television antenna

A television antenna, or TV aerial, is an antenna specifically designed for the reception of over the air broadcast television signals, which are transmitted at frequencies from about 41 to 250 MHz in the VHF band, and 470 to 960 MHz in the UHF band in different countries...

, or to cable TV systems which switched to digital cable

Digital cable

Digital cable is a generic term for any type of cable television distribution using digital video compression or distribution. The technology was originally developed by Motorola.-Background:...

. It normally does not refer to satellite TV, which has always required a set-top box

Set-top box

A set-top box or set-top unit is an information appliance device that generally contains a tuner and connects to a television set and an external source of signal, turning the signal into content which is then displayed on the television screen or other display device.-History:Before the...

either to operate the big satellite dish

Satellite dish

A satellite dish is a dish-shaped type of parabolic antenna designed to receive microwaves from communications satellites, which transmit data transmissions or broadcasts, such as satellite television.-Principle of operation:...

, or to be the integrated receiver/decoder

Integrated receiver/decoder

An integrated receiver/decoder is an electronic device used to pick-up a radio-frequency signal and convert digital information transmitted in it.-Consumer IRDs:...

(IRD) in the case of direct-broadcast satellites (DBS).

In North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, these ATSC tuner

ATSC tuner

An ATSC tuner, often called an ATSC receiver or HDTV tuner is a type of television tuner that allows reception of digital television television channels transmitted by television stations in North America, parts of Central America and South Korea that use ATSC standards...

boxes convert from ATSC

ATSC

ATSC standards are a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks....

to NTSC

NTSC

NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as...

, while in most of Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

and other places such as Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, they convert from Digital Video Broadcasting (DVB) to PAL

PAL

PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries. Other common analogue television systems are NTSC and SECAM. This page primarily discusses the PAL colour encoding system...

. Because the DTV transition did nothing to reduce the number of broadcast television system

Broadcast television system

Broadcast television systems are encoding or formatting standards for the transmission and reception of terrestrial television signals. There are three main analog television systems in current use around the world: NTSC, PAL, and SECAM...

standards (and in fact further balkanized it), and due to varying frequency allocation

Frequency allocation

Use of radio frequency bands of the electromagnetic spectrum is regulated by governments in most countries, in a Spectrum management process known as frequency allocation or spectrum allocation. Radio propagation does not stop at national boundaries...

s and bandplan

Bandplan

A bandplan or band plan is a plan for using a particular band of radio frequencies, that are a portion of the electromagnetic spectrum . Each bandplan defines the frequency range to be included, how channels are to be defined, and what will be carried on those channels...

s, there are many other combinations specific to other countries.

United States

On June 12, 2009, all full-power analog television

Analog television

transmissions went dark

Dark (broadcasting)

In the broadcasting industry, dark is a term used to describe a radio station or television station that has gone off-the-air for an indefinite period of time, or as defined by the U.S. Federal Communications Commission , a "silent" station...

in the United States. Viewers who watch broadcast television on older analog TV sets must use a DTA. Since many of the low-power TV stations will continue to broadcast in analog for years to come, consumers who watch low-power stations will need an adapter with an analog passthrough

Analog passthrough

Analog passthrough is a feature found on some digital-to-analog television converter boxes. Boxes without analog passthrough only allow digital TV to be viewed on older, analog-only TVs...

feature that allows the viewer to watch both digital and analog signals. Viewers who receive their television signals through cable or satellite were not affected by this change and did not need a digital television adapter (however, see the cable TV exception below). Additionally, viewers who have newer televisions with built-in digital ATSC tuners will not need an external digital television adapter.

The United States government had set-up a program to offer consumers a $40 "coupon" which can be used toward the purchase of a coupon-eligible converter box

Coupon-eligible converter box

A coupon-eligible converter box was a digital television adapter that met eligibility specifications for subsidy "coupons" from the United States government...

; that program ended in July 2009.

History

At the Consumer Electronics Association

Consumer Electronics Association

The Consumer Electronics Association is a standards and trade organization for the consumer electronics industry in the United States. The Consumer Electronics Association is the preeminent trade association promoting growth in the $173 billion U.S...

's Entertainment Technology Policy Summit in March 2006, Federal Communications Commission

Federal Communications Commission

The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...

(FCC) Commissioner Jonathan Adelstein

Jonathan Adelstein

Jonathan Steven Adelstein, the Administrator of USDA's Rural Utilities Service, is a former Commissioner on the Federal Communications Commission....

said many Americans did not know about the Feb. 17, 2009, deadline for ending analog TV. Furthermore, he said, too many people were still buying analog TV sets, meaning more demand for converter boxes. And even if people found out what they would have to do, converter boxes might not do the job adequately. Tribune Broadcasting

Tribune Broadcasting

The Tribune Broadcasting Company is a group of radio and television stations located throughout the United States which are owned and operated by the Tribune Company, a media conglomerate based in Chicago, Illinois and named for the flagship Chicago Tribune newspaper.- History :Tribune Broadcasting...

chief technology officer Ira Goldstone said just buying a converter box did not necessarily mean getting the latest technology. Bob Seidel of CBS

CBS

CBS Broadcasting Inc. is a major US commercial broadcasting television network, which started as a radio network. The name is derived from the initials of the network's former name, Columbia Broadcasting System. The network is sometimes referred to as the "Eye Network" in reference to the shape of...

said companies (especially in countries other than the US) might use cheaper tuners, and people would need new television antennas for proper reception. Circuit City Chairman Alan McCollough opposed converter boxes, saying people should just buy digital TVs, and television network

Television network

A television network is a telecommunications network for distribution of television program content, whereby a central operation provides programming to many television stations or pay TV providers. Until the mid-1980s, television programming in most countries of the world was dominated by a small...

s should offer only widescreen

Widescreen

Widescreen images are a variety of aspect ratios used in film, television and computer screens. In film, a widescreen film is any film image with a width-to-height aspect ratio greater than the standard 1.37:1 Academy aspect ratio provided by 35mm film....

-format television program

Television program

A television program , also called television show, is a segment of content which is intended to be broadcast on television. It may be a one-time production or part of a periodically recurring series...

ming as an incentive to do that.

Prototype

Prototype

A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.The word prototype derives from the Greek πρωτότυπον , "primitive form", neutral of πρωτότυπος , "original, primitive", from πρῶτος , "first" and τύπος ,...

s of the first converter boxes appeared at the NAB

National Association of Broadcasters

The National Association of Broadcasters is a trade association, workers union, and lobby group representing the interests of for-profit, over-the-air radio and television broadcasters in the United States...

show in 2006. LG Electronics

LG Electronics

LG Electronics is a global electronics and telecommunications company headquartered in Yeouido, Seoul, South Korea. The company operates its business through five divisions: mobile communications, home entertainment, home appliance, air conditioning and business solution...

, which took over Zenith Electronics

Zenith Electronics

Zenith Electronics Corporation is a brand of the South Korean company LG Electronics. The company was previously an American manufacturer of televisions and other consumer electronics, and was headquartered in Lincolnshire, Illinois. LG Electronics acquired a controlling share of Zenith in 1995...

in 1999, showed its model connected to a Zenith TV from 1980, while Thomson Consumer Electronics

Thomson SA

Technicolor SA , formerly Thomson SA and Thomson Multimedia, is a French international provider of solutions for the creation, management, post-production, delivery and access of video, for the Communication, Media and Entertainment industries. Technicolor’s headquarters are located in Issy les...

used an RCA

RCA

RCA Corporation, founded as the Radio Corporation of America, was an American electronics company in existence from 1919 to 1986. The RCA trademark is currently owned by the French conglomerate Technicolor SA through RCA Trademark Management S.A., a company owned by Technicolor...

from 1987 for its demonstration. Both boxes shown used electronic program guide

Electronic program guide

Electronic program guides and interactive program guides provide users of television, radio, and other media applications with continuously updated menus displaying broadcast programming or scheduling information for current and upcoming programming...

s using PSIP

Program and System Information Protocol

The Program and System Information Protocol is the protocol used in the ATSC digital television system for carrying metadata about each channel in the broadcast MPEG transport stream of a TV station and for publishing information about television programs so that viewers can select what to watch...

. The devices showed program details, V-chip

V-chip

V-chip is a generic term for technology used in television set receivers in the USA, Canada, and Brazil which allows the blocking of programs based on their ratings category. It is intended for use by parents to manage their children's television viewing...

ratings and signal strength. Thomson's model stored three days of TV listings, allowed parental controls, and could set a VCR.

Differences for cable customers

Cable TV systems are under no deadline to convert to digital TV. However, many Comcast

Comcast

Comcast Corporation is the largest cable operator, home Internet service provider, and fourth largest home telephone service provider in the United States, providing cable television, broadband Internet, and telephone service to both residential and commercial customers in 39 states and the...

(and some other cable TV) customers are finding all of their non-local and non-shopping networks eliminated on various dates, even though only a few are needed for additional digital cable

Digital cable

Digital cable is a generic term for any type of cable television distribution using digital video compression or distribution. The technology was originally developed by Motorola.-Background:...

channels. CECBs (Coupon-eligible converter boxes) will not work on these systems because cable ATSC uses 256QAM modulation

Modulation

In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...

instead of 8VSB

8VSB

8VSB is the modulation method used for broadcast in the ATSC digital television standard. ATSC and 8VSB modulation is used primarily in North America; in contrast, the DVB-T standard uses COFDM....

, and so a separate but similar DTA with a QAM tuner

QAM tuner

QAM stands for quadrature amplitude modulation, the format by which digital cable channels are encoded and transmitted via cable television providers...

is necessary. If the cable company takes away analog channels, at least two of these adapters must be provided for free by the cable company for at least three years (until June 2012), so that customers can continue to watch the channels they have paid for.

European Union

Most countries that have switched to digital TV use DVB-T

DVB-T

DVB-T is an abbreviation for Digital Video Broadcasting — Terrestrial; it is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in the UK in 1998...

broadcasting with MPEG-2

MPEG-2

MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods which permit storage and transmission of movies using currently available storage media and transmission...

MP@ML encoding. Some, however, consider switching to MPEG-4 H.264

H.264/MPEG-4 AVC

H.264/MPEG-4 Part 10 or AVC is a standard for video compression, and is currently one of the most commonly used formats for the recording, compression, and distribution of high definition video...

and also tests of DVB-T2

DVB-T2

DVB-T2 is an abbreviation for Digital Video Broadcasting – Second Generation Terrestrial; it is the extension of the television standard DVB-T, issued by the consortium DVB, devised for the broadcast transmission of digital terrestrial television....

have begun, the UK

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

being the first to test DVB-T2. This results in a number of different combinations for external digital receivers with the MPEG-2 ones sold at about €35 and the MPEG-4 ones reaching €150. Some of these receivers consume the rather high amount of 5W of electricity on standby mode.

United States

History

Differences for cable customers

European Union

See also