Emergency Broadcast System - National Level EBS

National Level EBS

An order to activate the EBS at the national level would have originated with the President and been relayed via the White House Communications Agency duty officer to one of two origination points: either the Aerospace Defense Command or the Federal Preparedness Agency—as the system stood in 1978. Participating telecommunications common carriers, radio and television networks, the Associated Press and United Press International would receive and authenticate (by means of code words) an Emergency Action Notification via an EAN teletypewriter network designed specifically for this purpose. These recipients would relay the EAN to their subscribers and affiliates.

The release of the EAN by the ADC or FPA would initiate a process by which the common carriers would link otherwise independent networks such as ABC, CBS and NBC into a single national network that even independent stations could receive programming from. "Broadcast stations would have used the two-tone Attention Signal on their assigned broadcast frequency to alert other broadcast stations to stand by for a message from the President." The transmission of programming on a broadcast station's assigned frequency, and the fact that television networks/stations could participate, distinguished EBS from CONELRAD. EBS radio stations would not transmit on 640 or 1240 AM, and television stations would carry the same audio program as AM radio stations.