CONELRAD and Conelrad CD Mark (CD Symbols)

In the midst of an on-going debate about how to make the best use of a national emergency alert system, I thought it would be interesting to take a look at one of the original alert systems dating back to the former Soviet Threat. In 1951, fearful of a Soviet attack, and determined to keep U.S. citizens alert, President Truman signed into existence the Control of Electromagnetic Radiation system, or CONELRAD. Back then, controlling electronic radiation meant keeping Soviet planes from tracking targets in the U.S. by tracking radio signals. To keep this from happening, CONELRAD called for commercial radio stations to stop broadcasting immediately when receiving an alert. Only select stations would stay on air, broadcasting on 640 or 1240 kHz.

Between 1953 and 1963, all radios sold in the United States were required to have the two CONELRAD frequencies marked clearly on the dial. If you have older radios in your home, or if you browse through older radios in a flea market, you can identify CONELRAD-era radios from the two small triangular marks on the dial known as CD symbols. These triangles provide a very useful identifying mark for radio collectors.

Sometimes the triangles are enclosed in small circles as well. Though some people think that the CD comes from the C and D in ConelraD, in fact CD stands for Civil Defense.

The Soviets shift towards ballistic missiles made CONELRAD obsolete. Ballistic missiles meant the possibility of long-distance strikes and there was no need for pilots to home in on targets from the air. The change in Soviet missile technology resulted in a change in the national emergency alert system. CONELRAD was replaced with the Emergency Broadcast System, which stayed with us until it morphed into the Emergency Alert System. Thus far, none of the national emergency alert systems have been used by a U.S. President.

Currently, national alerts can be broadcast to the public through a NOAA Weather Radio. For more information on the National Oceanic & Atmospheric Administration (NOAA) see our past What's in the News article titled NOAA One of the Best Kept Secret on the Web.

As always, please contact us with any comments or article suggestions you might have.

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