The following is a list of test cards used by the BBC at various points in broadcasting.
The first test card "Tuning Signals" was broadcast by the BBC in 1934. It was a simple line and circle broadcast using Baird's 30 line system, and was used to synchronise the mechanical scanning system.[1]
Test Card A made its debut in the late 1940s. However, it and Test Card B were soon replaced by the more useful Test Card C.[2]
Test Card B was an early BBC television test card. It was very similar to Test Card A but was never broadcast. The original card has since gone missing. The only difference was it had an extra greyscale stripe below the circle. The letter box in Test Card A was moved to the top of the card. This card was never broadcast, possibly used for by BBC engineers for internal use. Below is a reconstruction of Test Card B using a studio picture of a partial Test Card B.[2]
Test Card C is a BBC television test card first broadcast in 1948. It was the first test card to resemble the famous Test Card F.[2]
Test Card D was a BBC television test card first broadcast in 1964. This was the first test card to be based on a specification. Later, a "Reduced Power" Test Card D was introduced.[2]
Test Card E (shown on left) was a television test card designed in 1964 and made to accommodate the 625-line system on BBC2, as opposed to the 405-line system of Test Card D. However, it only lasted one day on television, and was soon replaced by a modified version of Test Card C (shown on right). This lasted until 1967 when the colour Test Card F was introduced.[2]
Test Card F was the BBC's longest-running and most famous test card, featuring Carole Hersee and Bubbles the Clown. There have been many different Test Card F variations. [2]
Test Card G was a television test card broadcast occasionally by the BBC. It was the first electronically generated test card to be broadcast, and was a variant of the Philips PM5544 test pattern. The testcard also use on RTM since 1979. [2]
Another Test Card G, unrelated, was developed by Pye as a variant on Test Card C. It was used in other countries that use 625-line PAL, but probably not in Britain.[2]
Test Card H abandoned in development - it was never broadcast. The "H" designation was also used for a studio line-up card, so it was not allocated to a Test Card to avoid ambiguity.[3]
Test Card J is an enhanced revision of Test Card F.[2]
Test Card W is a widescreen update of Test Card F. The Test Card was designed for the 16:9 (widescreen) ratio.[2]
The High Definition version of Test Card W is visually similar but officially lacks a designation letter. This version is often referred to as Test Card X, but this is not a designation which the BBC recognises.[4] It is designed for use on High Definition TV services, and has been included a part of BBC HD's preview loop since November 2008 (though has been in use internally at the BBC since several years earlier).
This is Sky's attempt to make a Sky HD test card that looks like Test Card F. Myleene Klass replaces Carole Hersee.[5]
An electronically generated image was first broadcast on 21 June 1997 on BBC2 between 3am and 4am. The test card was then seen again 17 April 2007 between 4am - 5am during the BBC Learning Zone both transmissions were accompanied by a 4-tone test tone, ranging from extremely low frequency to a very high shrill. It is unknown if this Test Card has a name.[2]
There has been a number of Un-Transmitted Test Cards. They would most likely be for internal use inside the BBC. Most of them are adapted from Test Card F.[2]
A Comic Relief Testcard was broadcast BBC1 on 18 March 1993 as part of Comic Relief.[2]