Recreation of ETP-1 used byIBAOff-air recording of ETP-1 as seen on ITV from 1979 to 1988
ETP-1 (orElectronic Test Pattern One)[1] was atest card designed and used by theIndependent Broadcasting Authority (IBA).[2][3][4] After test transmissions[5] from the IBA's Engineering Regional Operations Centre (ROC) in Croydon from 1978 it was phased in onITV over a period starting from 1979,[6] replacing, in different ITV regions:Test Card F,[7]Test Card G and full screen heightEBU colour bars.[8][9] After ITV went24 hours in 1988, the card ceased to be seen on the channel. It was used for both625-line PAL and405-line monochrome broadcasts.
Throughout the 1980s, it was seen extensively on bothChannel 4 andS4C during both their pre-launch tests and during the day, due to their limited broadcast hours early on, and shortly after launch it alternated with in-visionteletext broadcasts.[7] On these channels, it was captioned eitherIBA:CH4 orIBA:S4C,[10][11] 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 toNTL:CH4/NTL:S4C.[12] ETP-1 was last broadcast on 31 December 1992 after which Channel 4 showed4-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-nightteleshoppingblock,[13] S4C shows a closedown slide promoting itsS4C Clic VOD service withlibrary music playing in the background during off-air hours.[14]
On 18 April 2012, ETP-1 made one final appearance on Channel 4 to announce the loss ofanalogue television services in the London region. The card was shown from theCrystal Palace transmitter only, and was the last thing broadcast by analogue Channel 4 before the signal was switched off.[15]
