Editing Emergency Broadcast System (section)

====Attention Signal====
Next, the Attention Signal was transmitted. Prior to 1976, primary stations would turn their transmitters off for five seconds, back on for five seconds, off for five seconds more, then go back on air and transmit a 1000&nbsp;Hz tone for 15 seconds to alert secondary stations, as was used by predecessor [[CONELRAD]]. Television stations adhered to similar rules, but switched only their sound carriers off.<ref>{{cite book|title=Basic Emergency Broadcast System Plan|date=4 August 1967|publisher=Department of Defense|location=Washington, DC|page=33|edition=First Revision|url=https://www.scribd.com/document/80541666/Emergency-Broadcast-System-1967|access-date=27 October 2017|quote=Sound carrier only for TV stations|archive-date=31 July 2020|archive-url=https://web.archive.org/web/20200731000157/https://www.scribd.com/document/80541666/Emergency-Broadcast-System-1967|url-status=live}}</ref> This quick off-and-on became known to broadcast engineers as the "EBS Stress Test", as older transmitters would sometimes fail after the quick cycling on and off.<ref>{{Cite web |url=http://www.oldradio.com/current/bc_conel.htm |title=Broadcast History<!-- Bot generated title --> |access-date=2006-10-21 |archive-date=2015-04-05 |archive-url=https://web.archive.org/web/20150405012433/http://www.oldradio.com/current/bc_conel.htm |url-status=live }}</ref>

Starting in 1976, the two-tone Attention Signal (853 Hz and 960 Hz) was implemented, replacing the 1000 Hz tone and eliminating the need to switch the transmitter on and off. From 1976 to 1995, stations were required to broadcast the Attention Signal from the EBS encoder for 20 to 25 seconds; in mid-1995, a new rule was put in place that gave stations the option to transmit the attention signal for anywhere from eight to 25 seconds. Noncommercial educational FM radio stations operating at 10 watts or less and low-powered TV stations were exempt from transmitting the Attention Signal.<ref>{{cite web |author1=<!--Not stated--> |title=Emergency Broadcasting System standard operating procedures |url=https://www.fordlibrarymuseum.gov/library/document/0204/7348021.pdf |website=Gerald R. Ford Presidential Library & Museum |publisher=Federal Communications Commission |access-date=6 April 2023 |archive-url=https://web.archive.org/web/20230205002323/https://www.fordlibrarymuseum.gov/library/document/0204/7348021.pdf |archive-date=5 February 2023 |language=en-us |url-status=live}}</ref><ref>{{cite web | url=https://www.youtube.com/watch?v=jxmCYGdmcNs&ab_channel=ChrisShebel | title=North Carolina EBS Training | website=[[YouTube]] | date=19 May 2012 }}</ref>