WGU-20

WGU-20, also known as "the last radio station," was a radio station operated by the Defense Civil Preparedness Agency (now the Federal Emergency Management Agency) in the mid to late 1970s. Operating 24 hours a day on a longwave frequency of 179 kHz from Chase, Maryland, USA, the station's programming consisted of pre-recorded announcements and time checks.

Utilizing the world's first all solid state, 50,000 watt, radio transmitter, the signal covered much of the eastern seaboard and reception reports from as far away as Texas were greeted with a special QSL card featuring Paul Revere on a horse sounding an alarm.

The broadcast had a mechanical-like sound of early speech synthesis systems but the message could be clearly understood, with time ticks in the background and a continuous announcement akin to the Speaking clock: "Good evening. This is station WGU-20. Eastern Standard Time seventeen hours, twenty minutes, twenty seconds. Good evening. This is station WGU-20. Eastern Standard Time seventeen hours, twenty minutes, thirty seconds. Good evening. ..."

The station was quite a mystery for a while with thousands of ham radio operators and radio hobbiests speculating about the nature of the station. It wasn't until a small news article in Popular Electronics magazine outlined what WGU-20 was designed for.

WGU-20 was originally designed to be part of the Decision Information Distribution System (DIDS) that would be used to alert the public of an enemy attack (along the same lines as the then-current Emergency Broadcast System). As originally envisioned, many home devices, including radios, TV and even smoke detectors, would have inexpensive longwave receivers built into them ensuring the that attack message would get out.

The DIDS system was never implemented and the job of attack warning in the US remained with the EBS (now the Emergency Alert System).

External link

 * http://coldwar-c4i.net/index.html#PER
 * http://www.amrad.org/pipermail/tacos/2006/003650.html