A sign-on (or start-up in Commonwealth countries except Canada and Australia) is the beginning of operations for a radio or television station, generally at the start of each day. It is the opposite of a sign-off (or closedown in Commonwealth countries except Canada and Australia), which is the sequence of operations involved when a radio or television station shuts down its transmitters and goes off the air for a predetermined period; generally, this occurs during the overnight hours although a broadcaster's digital specialty or sub-channels may sign-on and sign-off at significantly different times than its main channels.
Like other television programming, sign-on and sign-off sequences can be initiated by a broadcast automation system, and automatic transmission systems can turn the carrier signal and transmitter on/off by remote control.
Sign-on and sign-off sequences have become less common due to the increasing prevalence of 24/7 broadcasting. However, some national broadcasters continue the practice; particularly those in countries with limited broadcast coverage. Stations may also sometimes close for transmitter maintenance, or to allow another station to broadcast on the same channel space.
Sign-on/start-up Sign-ons, like sign-offs, vary from country to country, from station to station, and from time to time; however, most follow a similar general pattern. It is common for sign-ons to be followed by a network's early morning newscast, or their morning or breakfast show.
Some broadcasters that have ceased signing on and signing off in favour of 24-hour broadcasting may perform a sign-on sequence at a certain time in the morning (usually between 4 and 7 a.m.) as a formality to signify the start of its operating day (in the United States, the broadcast logging day begins at 6 a.m. local time). These may be the switchover from network-provided overnight programming to the early morning newscast, which is the first live program of the day.
Sign-on/start-up sequence The sign-on sequence may include some or all of the following stages, but not necessarily in this order: For television or radio stations that cut off their signal during off-broadcast hours, a test pattern or a static image accompanied by a 400 Hz tone, a 1 kHz tone (or other single-sine-wave tones) or music may be broadcast fifteen to twenty minutes before the actual sign-on. Digital channels may still run overnight programs or interstitials at this time (ITV Nightscreen in the United Kingdom being an example), which conclude when the station's main programming schedule begins. A signal to turn on remote transmitters may be played—this is usually a series of touch tones. On radio stations, especially international stations on shortwave, an interval signal may be played in a loop, usually for 3 to 5 minutes before the actual broadcast starts. Technical information is provided. This can include station identification (call sign and city of license), transmitter power, frequency or channel number, translators used, transmitter locations, list of broadcast engineers, and/or studio/transmitter links (STL). A television station may show a video and photo montage set to the national anthem or other patriotic piece of music. The accompanying television video may include images of the national flag, the head of state, national heroes, national military soldiers, national symbols, and other nationalistic imagery (especially on state-owned broadcasters), or simply the station ident. In the case of television stations broadcasting to audiences in more than one country, the flags and national symbols of each country in turn may be shown, with its respective national anthem being played. Ownership information about the station, and a list of related organizations. A video of people singing an opening song, or opening dance performance to start the day. A greeting to viewers or listeners. Contact information, such as street and mailing addresses, telephone number, email, and website details. A prayer or other religious acknowledgement, particularly in countries with a state religion, in theocracies, and on religious broadcasters. A schedule for the upcoming programs, or the day's programs. A disclaimer that station programming is taped, aired live, or originates from a television or radio network. Another disclaimer that programs are for personal use only (sometimes with information on copyright restrictions), and a statement that businesses cannot profit from showing them by applying a cover charge for viewing. A statement of commitment to quality; this may be in the form of a recognized standard, such as the Philippines' Broadcast Code of the Kapisanan ng mga Brodkaster ng Pilipinas (Association of Broadcasters of the Philippines). A station identification, including some or all of the television channel, AM or FM frequency, call sign, branding, and a clock ident. Generally a station jingle or slogan will be played, accompanied on television with video clips featuring station programming or personalities. The Start-Up/Sign-On Notice is announced after the national anthem.
While most of these sign-on steps are done as a service to the public, or for advertising reasons, some of them may be required by the government of the country.
Sign-off/closedown Sign-offs, like sign-ons, vary from country to country, from station to station, and from time to time; however, most follow a similar general pattern. Many stations follow the reverse process to their sign-on sequence at the start of the day.
Many stations, while no longer conducting a sign-off and being off air for a period of time each day, instead run low-cost programming during those times of low viewer numbers. This may include infomercials, movies, television show reruns, simple weather forecasts, low cost news or infotainment programming from other suppliers, simulcasts of sister services, or feeds of local cable TV companies' programming via a fiber optic line to the cable headend. Other broadcasters that are part of a radio or television network may run an unedited feed of the network's overnight programming from a central location, without local advertising. During what are otherwise closedown hours, some channels may also simulcast their teletext pages or full page headlines with music or feeds from sister radio stations playing in the background. Some stations, after doing a sign-off, nonetheless continue to transmit throughout the off-air period on cable/satellite; this transmission may involve a test pattern, static image, local weather radar display, teletext pages or full-page headlines which was accompanied by music or a local weather radio service.
Some broadcasters that have ceased signing on and signing off in favour of 24-hour broadcasting may perform a sign-off sequence at a certain time in the night (usually between 10 p.m. and 1 a.m.) as a formality to signify the end of its operating day (in the United States, the broadcast logging day ends at 4 a.m. local time).
Sign-off/closedown sequence
The sign-off sequence may include some or all of the following stages, but not necessarily in this order:
An announcement informing viewers that the station is about to go off-air: it may also include a message of thanks for the viewer's patronage, along with an announcement of the time when the station is scheduled to sign on again. A station jingle or slogan may be played, accompanied on television with video clips featuring station programming or personalities, or perhaps stock scenes from the station's main city/cities. A series of program trailers may also be played. A prayer, hymn, or other religious acknowledgement, particularly in countries with a state religion or theocracies, and on religious broadcasters. Other channels may opt for a pre-taped sermonette or something similar. See section below. A short newscast and weather forecast. Stations also show PSAs through Ad Council or any organizations, for instance; some channels in the United Kingdom also included a public information film. Meanwhile, in the United States, it is common for a brief news reel to be broadcast over the station's logo, often accompanied by public service and missing and most wanted persons announcements. A clock ident, which can be silent, play music or feature an announcer. A program guide for the following day's programs. Closing credits acknowledging announcers, technicians and other crew who operated the day's broadcast. Ownership information about the station and their parent company, as well as their contact information, such as street and mailing addresses, telephone or fax number, zip code, e-mail, and website details. A video of people singing a closing song, or closing dance performance to end the day's broadcast. A disclaimer that programs are for personal use only (sometimes with information on copyright restrictions), and a statement that businesses cannot profit from showing them by applying a cover charge for viewing. A disclaimer that station programming may be taped, aired live, or originates from another television or radio network. Technical information provided, such as the call sign, transmitter power, translators used, transmitter locations, a list of broadcast engineers (in the Philippines only), and studio/transmitter links (STL). The viewer may be encouraged to view or listen to alternative services during the station's downtime; these are usually sister or affiliate stations. A statement of commitment to quality, usually in the form of a recognized standard: in the Philippines, it is usually the Broadcast Code of the Kapisanan ng mga Brodkaster ng Pilipinas (Association of Broadcasters of the Philippines), while in the United States, it was (until 1983) the Television Code of the National Association of Broadcasters. Same as the start-up, the closedown/sign-off notice is shown before the National Anthem. A television station may show a video and photo montage set to the national anthem or other patriotic piece of music. The accompanying television video may include images of the national flag, the head of state, national heroes, national military soldiers, national symbols, and other nationalistic imagery (especially on state-owned broadcasters, but sometimes on privately owned ones too), or simply the station ident. In the case of television stations broadcasting to audiences in more than one country, the flags and national symbols of each country in turn may be shown, with its respective national anthem being played. Stations in the German-speaking parts of Europe (DACH) would use a slide with the station logo and the word Sendeschluss (in Germany and Austria also alternatively spelt Sendeschluß with an eszett), meaning "shutdown", shown prior to the test card (as opposed to before the signal being cut) to tell the viewer to switch off their sets. This practice ceased around 1994–96. The station may display some type of novelty item, such as an animated character, particular to that station or its locale. Viewers may be reminded to turn off their television sets just prior to the transmitter being switched off. This was historically practised in the United Kingdom, German-speaking Europe and many parts of the Eastern Bloc, and is still in regular practice in places like Russia and some areas of Japan. Sometimes, a loud tone may be played on the audio to encourage sleeping viewers to turn their television sets off, in order to prevent electricity wastage and mitigate the risk of fires and/or explosions occurring in older TV sets. On channels intended for young children, a short video may be shown of the channel's characters or hosts going to bed, before showing a loop of them sleeping throughout the night until programming resumes the following morning.