ETP-1 (or Electronic Test Pattern One) was a

test card A test card, also known as a test pattern or start-up/closedown test, is a television test signal, typically broadcast at times when the transmitter is active but no program is being broadcast (often at sign-on and sign-off). Used since the ea ...

designed and used by the

Independent Broadcasting Authority The Independent Broadcasting Authority (IBA) was the regulatory body in the United Kingdom for commercial television ( ITV and Channel 4 and limited satellite television regulation – cable television was the responsibility of the Cable Author ...

(IBA). After test transmissions from the IBA's Engineering Regional Operations Centre (ROC) in Croydon from 1978 it was phased in on ITV over a period starting from 1979, replacing, in different ITV regions:

Test Card F Test Card F is a test card that was created by the BBC and used on television in the United Kingdom and in countries elsewhere in the world for more than four decades. Like other test cards, it was usually shown while no programmes were being ...

, Test Card G and full screen height

EBU colour bars The EBU colour bars is a television test card used to check if a video signal has been altered by recording or transmission, and what adjustments must be made to bring it back to specification. It is also used for setting a television monitor ...

. After ITV went 24 hours in 1988, the card ceased to be seen on the channel. It was used for both

625-line 625-lines is a standard-definition television resolution used mainly in the context of analog systems. It was first demonstrated by Mark Iosifovich Krivosheev in 1948. Analog broadcast television standards The following International Telecommuni ...

PAL and

405-line The 405-line monochrome analogue television broadcasting system was the first fully electronic television system to be used in regular broadcasting. The number of television lines influences the image resolution, or quality of the picture. It wa ...

monochrome broadcasts. It was also seen extensively on both

Channel 4 Channel 4 is a British free-to-air public broadcast television network operated by the state-owned Channel Four Television Corporation. It began its transmission on 2 November 1982 and was established to provide a fourth television service ...

and S4C during both their pre-launch tests and their downtime of those channels, due to their limited hours early on. After launch, it was alternated with in-vision

teletext A British Ceefax football index page from October 2009, showing the three-digit page numbers for a variety of football news stories Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipp ...

services from ORACLE and

4-Tel on View Channel 4 is a British free-to-air public broadcast television network operated by the state-owned Channel Four Television Corporation. It began its transmission on 2 November 1982 and was established to provide a fourth television service i ...

/ Sbectel. On these channels, it was captioned either IBA:CH4 or IBA:S4C, with lines above and below this indicating the card was being generated by the channel, the absence of these lines meant it was generated at the transmitter. After the splitting up of the IBA in 1990, the captioning was changed to

NTL NTL may refer to: Companies * NTL Incorporated and NTL Internet, later Virgin Media, communications media company ** NTL Ireland, later Virgin Media Ireland * Arqiva, UK company formerly ''NTL Broadcast'' and ''National Transcommunications L ...

:CH4/NTL:S4C. ETP-1 was last broadcast on 31 December 1992 after which Channel 4 showed ''4-Tel on View'' during closedown periods as the channel gradually increased its late night programming, eventually going 24 hours a day early in 1997. After the conclusion of its late-night teleshopping

block Block or blocked may refer to: Arts, entertainment and media Broadcasting * Block programming, the result of a programming strategy in broadcasting * W242BX, a radio station licensed to Greenville, South Carolina, United States known as ''96.3 ...

, S4C shows a closedown slide promoting its S4C Clic VOD service with

library music Production music (also known as stock music or library music) is recorded music that can be licensed to customers for use in film, television, radio and other media. Often, the music is produced and owned by production music libraries. Backgroun ...

playing in the background during off-air hours. On 18 April 2012, ETP-1 made one final appearance on Channel 4 to announce the loss of

analogue television Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, phase and frequency of an analog s ...

services in the London region. The card was shown from the

Crystal Palace transmitter The Crystal Palace transmitting station, officially known as Arqiva Crystal Palace, is a broadcasting and telecommunications site in the Crystal Palace area of the London Borough of Bromley, England (). It is located on the site of the former t ...

only, and was the last thing broadcast by analogue Channel 4 before the signal was switched off.

Operation

The test card was generated electronically by a video generator, and includes features for various adjustments and checks: *Crosshatch pattern - For CRT color convergence check *

- Six colour bars at 75%

amplitude The amplitude of a periodic variable is a measure of its change in a single period (such as time or spatial period). The amplitude of a non-periodic signal is its magnitude compared with a reference value. There are various definitions of am ...

and 100%

saturation Saturation, saturated, unsaturation or unsaturated may refer to: Chemistry * Saturation, a property of organic compounds referring to carbon-carbon bonds **Saturated and unsaturated compounds ** Degree of unsaturation **Saturated fat or fatty aci ...

for colour adjustments *

Greyscale In digital photography, computer-generated imagery, and colorimetry, a grayscale image is one in which the value of each pixel is a single sample representing only an ''amount'' of light; that is, it carries only intensity information. Gray ...

bar - Six bars at 0%, 20%, 40%, 60%, 80% and 100% amplitude. Allows checking of brightness

linearity Linearity is the property of a mathematical relationship ('' function'') that can be graphically represented as a straight line. Linearity is closely related to '' proportionality''. Examples in physics include rectilinear motion, the linear ...

. *Multiburst - Six bars of sine wave frequency gratings for

bandwidth Bandwidth commonly refers to: * Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range * Bandwidth (computing), the rate of data transfer, bit rate or thr ...

resolution Resolution(s) may refer to: Common meanings * Resolution (debate), the statement which is debated in policy debate * Resolution (law), a written motion adopted by a deliberative body * New Year's resolution, a commitment that an individual mak ...

check ( 625 lines: 1.5, 2.5, 3.5, 4.0, 4.5, 5.25 MHz ;

: 1.0, 1.6, 2.25, 2.6, 2.9, 3.4 MHz ). *150 kHz square waves - Transient response check, placed above the colour bars. *Black rectangle within white rectangle - For low frequency response check. *White needle pulse - Signal reflections check. *Yellow-red-yellow rectangles -

Chrominance Chrominance (''chroma'' or ''C'' for short) is the signal used in video systems to convey the color information of the picture (see YUV color model), separately from the accompanying luma signal (or Y' for short). Chrominance is usually represente ...

/ luminance

delay Delay (from Latin: dilatio) may refer to: Arts, entertainment, and media * ''Delay 1968'', a 1981 album by German experimental rock band Can * ''The Delay'', a 2012 Uruguayan film People * B. H. DeLay (1891–1923), American aviator and acto ...

check. * Line synchronisation castellations - Pattern of rectangles in black and colours. *Colour receiver reference oscillator castellations - Correct color decoding check (Top: cyan, Bottom: green, Left: red, blue, Right: yellow). *Picture centering castellations - some overscan is normal, but castellations should be visible along all sides of the picture.

References

{{Standard test item Test cards Broadcast engineering British inventions Telecommunications-related introductions in 1978 1978 in British television 1978 establishments in the United Kingdom 1992 disestablishments in the United Kingdom

Operation

See also

References