“Miss those old two-tone attention signals, do we?”
Actually, the two-tone signal was an innovation that came more than a decade after the EBS was implemented (around 1976), and it was in response to a system failure. The Emergency Broadcast System itself grew out of the CONELRAD (Control of Electronic Radiation) system created in 1951.
A decent description of CONELRAD can be found at http://www.westgeorgia.org/conelrad/ and a brief history of how EBS and ENS came to be can be found at http://www.oldradio.com/current/bc_conel.htm However, oldradio.com’s description of the EBS attention signal pre-1976 is incorrect (see: http://www.akdart.com/images/EBS-att.png).
