| | Television Test Cards, Tuning Signals, Clocks and Idents |
 | | Of course special test generators were available that could be used to make accurate measurements of the performance of every aspect of the studio and distribution equipment, but again, how useful it would be to have a pattern that could give a rough indication of performance (or lack of it) from camera to screen. |
 | | Test Card W (16:9) that included almost all the features of Test Card F, had the central colour picture digitally remastered from the original colour reversal transparency, and had additional tests required for digital operations. |
 | | The intention was to use Test Card D on 405-lines and Test Card E on 625-lines, but BBC engineers were unhappy with the appearance of the TCE frequency gratings and so this card, which never sported an identification letter, was retained until the start of the colour service in July 1967. |
| www.pembers.freeserve.co.uk /Test-Cards#Birth (6822 words) |