Sign-on and sign-off

A sign-on (or start-up in Commonwealth countries except Canada) 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), 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 as 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-hour-a-day, seven-day-a-week 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 4:00 and 7:00 a.m.) as a formality to signify the start of its operating day (in the United States, the broadcast logging day begins at 6:00 a.m. local time).

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 Hertz 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 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.

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 weather forecast and newscast: some channels in the United Kingdom also used to include a public information film.
* 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.
* 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.
* 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.
* The station may display some type of novelty item, such as an animated character, particular to that station or its locale.
* 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.
* 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 and in many parts of the Eastern Bloc, and is still in regular practice in some 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 to mitigate the risk of fire 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.
* Finally, stations may show a test card, station logo, a loop of the station ident, a black screen, or a static schedule (telling viewers of the programming line-up once broadcasting resumes), usually with a monotone sound or a relay of a radio station: some stations, such as BBC Two, may show a sequence of teletext pages, while others may use a promotional video or a series of infomercials. Other stations may simply cut off the signal, usually by sending a series of touch tones to turn off remote transmitters, which resulted in static on an analog television signal. Others may switch into a 24-hour channel or show archived programming.

Some countries have a legal protocol for signing-off: in the United States, the minimum requirement is the station's callsign, followed by its designated city of license. Many stations do include other protocols, such as the national anthem or transmitter information, as a custom, or as a service to the public.

In the United Kingdom, before the introduction of 24-hour television, there was no known legal protocol for a sign-off: BBC One and many ITV regions customarily included a continuity announcement, clock and the country's national anthem (for BBC One Wales and HTV Wales, ''Hen Wlad Fy Nhadau'' was also played beforehand), while BBC Two, Granada, Border, and Channel 4 signed-off with just a continuity announcement, clock and ident.

In Germany, it is a custom to play the national anthem (for Bayerischer Rundfunk and stations owned by ProSiebenSat.1 Media, the ''Bayernhymne'' was also played beforehand) and the European Union anthem.

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 persons announcements.

Religious acknowledgements during sign-on and sign-off

Special sign-on/off cases

Historical

In a number of countries closedowns formerly took place during the daytime as well as overnight. In the United Kingdom this was initially due to government-imposed restrictions on daytime broadcasting hours, and later, due to budgetary constraints. The eventual relaxation of these rules meant that afternoon closedowns ceased permanently on the ITV network in October 1972, but the BBC
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