Test Card G

The following is a list of test cards used by the BBC at various points in broadcasting.

The first "Tuning Signals" test card 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.

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.T

Test Card B was an early BBC television test card. It was very similar to Test Card A but was never broadcast, possibly used for by BBC engineers for internal use. 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.

Test Card C was a BBC television test card first broadcast in 1948. It was the first test card to resemble the famous Test Card F.

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.

Test Card E 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 and still called Test Card C. This lasted until 1967 and then again in 1976 when the colour Test Card F was introduced.

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.

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