What Were TV Test Cards For?

If you grew up in the U.S. before 24-hour television programming, you might remember falling asleep to the sound of the national anthem or waking up to the eerie tone of a test pattern. Local stations typically signed off late at night — often with patriotic imagery and music — before going dark or switching to a test card. Early risers or insomniacs who turned on the TV were thus greeted by screens filled with color bars or geometric patterns accompanied by a high-pitched tone, holding the airwaves until regular programming resumed at dawn. These ...Read More