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Postwar picture perfection - thanks to the testcard

By Black Country Bugle User  |  Posted: October 05, 2006

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Part of a television engineer's bible in years gone by was the 'Schedule of Morning Trade Transmissions' which he used as a guide when testing televisions either in the showroom or out on the road.

Alan Keeling has sent us the details of a schedule taken from a 1959 copy of Wireless World, showing the precise times there would be a test card or a still picture showing on the screen, plus music being played for sound quality, on both BBC and ITA. For the boffins amongst us the BBC and ITA were two distinctly different animals as the schedule text reveals:

"BBC Signals : Recorded music is on magnetic tape. On Mondays only, when the TV distribution network is handed over to the GPO for maintenance and test, all TV transmitters (except Crystal Palace) will radiate locally generated test card C or other test signal from 10 am to 1 pm. When experimental colour transmissions are in progress from Crystal Palace, they will conform to the same schedule as used in the monochrome transmissions. When experimental stereo broadcasts, using the TV sound channels, are in progress the normal sound accompanying the trade test will be modified as necessary. In the event of reduced power being used, the vision signal will consist solely of a locally generated test card bearing the inscription "reduced power". Where facilities are not available, a locally generated line bar signal will be used.

"ITA Signals : The recorded music is on commercial l.p. discs. Test cards and still pictures are originated at each transmitting station and the sound is networked from Croydon. In the event of reduced power being used, the words "reduced power" will be superimposed on the test card."

As Alan explains, the music used by ITA was commercially available. "The long playing records included musicians and performing artists of the day such as Frank Chacksfield, Nelson Riddle, Chris Barber, etc., plus of course classical pieces of music by Beethoven, Mozart and Dvorak, etc. The still pictures were of several scenes shown by showroom dealers to demonstrate picture quality to prospective customers.

"Two of the most popular still scenes transmitted from Lichfield were Ludlow's bridge and castle and the River Trent in Staffordshire."

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