If you grew up between 1947 to the 1970s, you’re probably familiar with the RCA Indian head te

If you grew up between 1947 to the 1970s, you’re probably familiar with the RCA Indian head test pattern. 

It was transmitted at the end of the broadcast day and at regular intervals during the day, so TV owners could calibrate their sets, and broadcasters could check their signals. Each part of the transmission had a function.