FROM THE ARCHIVE OF: The TV Room
In the days before 24-hour television.
[00:00:00] TEST CARD: shortly after the Channel 4 announcer bid us goodnight, the IBA/Ch 4-branded ETP-1 electronic test card would appear, accompanied by test tone.
It would remain in place for c. 15 minutes. The overnight shutdown of the Channel 4 transmitter network would then be triggered.
PICTURED: Channel 4 test card. COPYRIGHT: Channel 4 Television Corporation.