Did you know that US car radios used to be required to have CONELRAD frequencies marked?

We certainly didn’t. Once thermonuclear weapons made the scary transition from theory to reality in 1952, Americans realized that they had a scary chance of facing Soviet jet bombers armed with megaton-grade H-bombs, not just low-budget B-29 clones carrying quaint kiloton-sized fission weapons. This fear inspired the creation of the CONELRAD system, which would broadcast emergency nuclear-attack alerts on two AM radio frequencies. By the 1953 model year, car radios sold in the United States had to be marked with the Civil Defense triangle logo at 640 and 1240 kHz… read more >