Thames Television (UK)

1968–1989 (primary), 1989–1992 (secondary)

1968–1969

1989–1990

1989-1990 (ITV)

1990–1992

1990-1991 (ITV)

1969–1989 (primary), 1989–1992 (secondary), 1999-2008

2008-2019

2019-present