In case anyone is upset by the censoring of the test card on the first page, here is a collection of images of various test cards.
Starting with one of the most famous images in British television - Test Card F, featuring the most-seen person ever on our screens, Carole Hersee. The first two captures are from broadcasts in the 1970s when much of daytime television was made up of these trade test transmissions. Both BBC1 and BBC2 used the same slide - for BBC1, the channel identification was electronically superimposed over the top of the '/B/B/C/2/ COLOUR' legend.
In 1984, Test Card F switched to an electronically-generated version. The third capture is from an early morning transmission in November 1998, shortly before regular broadcasts ceased.
Updated versions of the test card, named Test Card J for the 4:3 version and Test Card W for the 16:9 widescreen version, were introduced in the late 1990s, for which the centre image was rescanned. The captures here are taken from overnight rebroadcast tests on 27th July 2001. Test Card W was broadcast on the digital version of BBC1, while analogue showed Test Card J, although initially it showed a 4:3 centre cut-out of Test Card W before opting out of the digital feed.
The tests involve cutting the network analogue feed to all transmitters except Crystal Palace. Each main transmitter therefore has to pick up off-air the signal from the nearest transmitter and re-broadcast it. In theory then, the signal should weaken the further you go from London. This appeared to be the case - reports from the North of England indicated weak reception with interference and dropout; whereas here in the South East I was able to receive a perfectly clear picture as usual.
Two images of the lesser-spotted Test Card G - the first is from the 1970s, while the second is a capture of an ultra-rare 21st century showing, when Test Card G made an appearance on BBC Parliament on the afternoon of Saturday 30th August 2003.
The third image is of ETP-1 (Electronic Test Pattern 1) which is best known for its appearances on Channel 4, but was also broadcast on ITV until 1988. This showing dates from 18th April 2012, at the point that Channel 4's analogue television transmissions ceased in the London region.
Today, Test Card W can be spotted for a short period just before the start of morning broadcasts on BBC2, and comes complete with an audio sync test, consisting of animated grey bar which repeatedly scrolls across the bottom of the screen, with a 'click' sound when it reaches the centre mark. A high-definition version of Test Card W was formerly broadcast on the BBC HD channel until its closure in 2013.
From our YouTube channel, some clips of the switch-off of analogue television from 2012, featuring ETP-1.