by James Kraus
In 1951, the U.S. government initiated the CONELRAD (CONtrol of ELectromagnetic RADiation) system in an effort to prevent the possibility of incoming Russian bombers using transmitting signals from U.S. broadcast antennas as navigational aids.
Under CONELRAD protocol, if an enemy attack was determined to be imminent, all commercial radio and television stations would be ordered to immediately cease broadcasting. Pre-selected AM stations in each region would then begin transmitting on one of two specific frequencies, 640 and 1240 kHz. Every few minutes the broadcast would switch among pre-determined stations in the same region, giving instruction and solace to the general populace.
The constant switchover of transmission points precluded using transmission towers as potential beacons to guide hostile aircraft toward population centres. During the CONELRAD operational period, all radios sold in the U.S. were required to display the triangular Civil Defense symbol at the AM 640 and AM 1240 positions on the tuning dial.
The successful development of atomic warhead delivery via ballistic missiles rendered CONELRAD obsolete and it was superseded by the Emergency Broadcast System in August of 1963. The EBS did not require tuning-in to any specific frequencies, and the classic triangles disappeared from automobile radios with the debut of the 1964 models.
Other than for routine testing, CONELRAD was never activated. The closest it came to implementation was during the height of the 1962 Cuban Missile Crisis. As the Cold War confrontation escalated toward its peak, the U.S. Strategic Air Command initiated DEFCON II (Code Red) status at 10:00 PM, Friday, 26 October. This remains the highest DEFCON threat level ever officially confirmed to date. Nuclear armed interceptors and bombers were either on airborne alert or staged at fifteen-minute readiness status.
Heightened tensions were further strained several hours later on Black Saturday when an American U2 spy plane was shot down near Cuba by a pair of Soviet S-75 Dvina surface-to-air missiles.
That evening, radio station operators were told to stand by and prepare to initiate CONELRAD operations at or any time after 10:00 the following morning.
After all-night negotiations, Russia agreed at 9:00 AM Sunday morning to remove their missiles from Cuba in exchange for the removal of U.S. intermediate-range missiles from bases in Italy and Turkey.