A special feature of the NOAA Weather Radio system that evolved in the 1960's was the transmission of a single tone at 1050 Hz prior to the broadcast of any message about a life or property threatening event. This became known as the Warning Alarm Tone (WAT). Special receivers were made by several companies to remain electronically on and receiving the broadcast signal, but with the speaker muted. When this type of radio detected the WAT, it automatically turned on the speaker allowing the message to be heard without the need for the owner/user to do anything.
In the Spring of 1974, the largest recorded outbreak of tornadoes in the nation’s history occurred. Conclusions of a survey following the disaster recommended the expansion of the Weather Radio network and to designate it as the only Federally operated broadcast system to communicate life and property threatening information “directly” to the public. This system was also tasked to disseminate nuclear attack warnings and other national emergencies. Techniques were developed allowing warnings broadcast over the Weather Radio to be rebroadcast over commercial radio and television stations as part of the Emergency Broadcast System (EBS).
The analog WAT technology served the Weather Radio network well until the mid 1980s, when the rapid expansion of cable television and the automation of commercial radio and television began to isolate the public from local sources of warning information. Typically, the WAT was transmitted for any watch or warning over an area of approximately 5,000 square miles, or about seven to ten average-sized counties.
Therefore, the typical receiver in the service area of the station might be activated many times for events far from its location for every time it alarmed for an event in the immediate area. Without staff at media facilities to manually evaluate the need to rebroadcast a Weather Radio message using the EBS, automatic rebroadcasting of all messages preceded by just the WAT was unacceptable and impractical. Even if stations and others with that type of need were willing to allow for this type of automatic capture, assuming the events for activation were critical, there was no way for automated equipment at the station to know when the message was complete and restore it back to normal operation. There was also the perception by the general public with WAT decoding receivers that any message that set their radio off that did not apply to their geographical area was a “false alarm” regardless of whether the warning may have been valid for another area or county in the service area of the Weather Radio transmitter.
Starting in 1985, the NWS began experimenting with putting special digital codes at the beginning and end of any message concerning life or property threatening event. The intent was to ultimately transmit a code with the initial broadcast of all Weather Radio messages. This system evolved into what is known today as NOAA Weather Radio Specific Area Message Encoding (NWR SAME). The SAME was adopted by the NWS for national implementation in 1988. Full scale implementation was funded by the NWS in early 1996 when the SAME technique was adopted by the Federal Communications Commission (FCC) as part of its new Emergency Alert System (EAS) that replaced the EBS in January 1997. The NOAA Weather Radio was an officially designated source for EAS messages from the NWS.
The SAME process was originally achieved using an encoder panel consisting of a number of buttons representing the functions to be performed, types or content of messages, the affected areas, and valid time of the message. A microprocessor in the panel interpreted button active status and created the proper codes and places them at the beginning and end of each message. The panel was electronically connected to the various types of message programming and playback consoles used by the NWS to broadcast messages over the Weather Radio transmitters. In 1998, the NWS replaced all of its existing inventory of message recording and playback equipment with the Console Replacement System (CRS). The SAME coding process is an integrated part of CRS. The existing encoder panels are only used as emergency backup in CRS.