The PBS Satellite Service (also known as the PBS National Program Service, with the primary C-band feed being formerly known as PBS Schedule X in Eastern Time, with the West Coast delay signal designated PBS-XP) consists of feeds relayed from PBS by satellite to public television stations throughout the United States. The service launched on March 1, 1978, with wider adoption beginning in September 1978 as more satellite downlinks were installed at each PBS stations. The service provides a mixed variety of programming selected from PBS's regular network services. In the X/XP years a satellite feed was multicast by some PBS member stations on an over-the-air DTV subchannel along with their regular programming, or during overnight hours on their main channel to provide a second opportunity for viewers to watch or record primetime programming.
PBS currently utilizes one transponder on the Galaxy 16 satellite, transponder 22. This is a MCPC (multiple channel per carrier) which currently has seven channels uplinked from the PBS NOC (Network Operations Center) in Alexandria, Virginia. However, in the event of approaching weather or technical difficulties at the NOC in Virginia, PBS will switch to a backup uplink location in Lincoln, Nebraska.
Currently, select stations broadcast the feed, usually overnight, like KGTF (PBS Guam, broadcasts most of the channel as a localised feed). The primary feed, known as HD01, is also available over satellite providers like DirecTV (Channel 389), though this feed is down-converted to SD. PBS provides all of their channels free to TV providers who do not receive local member stations.
As of 2026, PBS's satellite feeds, as well as a few other PBS stations, can be received unscrambled using a free-to-air satellite receiver set to these coordinates: PBS National Program Service at 99°W (on the Galaxy 16 satellite), Ku-band, unencrypted. Montana PBS at 99°W (on the Galaxy 16 satellite), Ku-band, unencrypted. LPB (along with LPB Kids and LPB 3) at 101ºW on the SES-1 satellite, Ku-band, unencrypted.
PBS affiliate KETA, part of the Oklahoma Educational Television Authority (OETA), was also available on AMC-21 until June 2016. Their removal from satellite coincided with the completion of their transition to fiber distribution. In March 2026, LPB begain simulasting on the SES-1 satellite. Later in the month, LPB shut down their transponder on SES-2 at 87ºW (where the station has been uplinking to since 2003 when it was originally known as AMC-3) competing the transition to SES-1.
PBS transitioned to a fiber-based interconnection system known as sIX, otherwise known as the sixth generation of PBS's interconnection system, in July 2021. The original end date for linear program feeds via satellite was slated for 2016, but was later pushed to 2018, and was then pushed again to the beginning of 2021; none of these deadlines were met. PBS's main network feeds are still active as of March 2026; however, only one NPS soft-feed service remains, namely HD03. The only programs airing on this feed are news and public affairs programming; all other linear program feeds have moved to sIX; however, there may occasionally be an unannounced feed of program unrelated to news or public affairs, such as re-feeds of certain live events, such as certain episodes of Great Performances.
History
1971–1978: The First-Generation Interconnection System Starting in 1971, PBS began distributing programs via microwave relay circuits leased from AT&T Long Lines. This was the first generation of PBS's interconnection system. Prior to this, PBS would distribute programs to stations via "bicycling tapes," meaning that tapes would be shipped between stations through the mail. The interconnection system consisted of nearly 20,000 miles of microwave paths spread across the country. To send programming, PBS would feed these videotaped programs via the AT&T network of microwave relay circuits throughout the country. Instead of each program being received by each individual public television station, these programs were fed to "regional networks," which would then redirect these feeds to stations within their network. Examples of these regional networks included the Southern Educational Communications Association (SECA), which is now known as the National Educational Telecommunications Association (NETA); the Central Educational Network (CEN); the Eastern Educational Television Network (EEN), which is now known as American Public Television (APT); and Midwestern Educational Television (MET). This system made use of a "round-robin" method when distributing programming; this meant that, "a number of stations on the loop can originate to all other stations in the system."
Issues with the System The system, however, had its limits. One problem was that video and audio quality would become poorer the farther away a receiving station was due to the distance the program had to travel via the interconnection system. Furthermore, for areas outside the contiguous U.S., such as Hawaii, connecting to the interconnection system was not "economically feasible"; to acquire programming, these stations were sent videotapes via the mail. Another issue was that this system was single channel only, meaning that PBS could not feed multiple programs at the same time, giving stations less programming options. There were also issues with making last minute changes to programming if PBS needed to pre-empt a previously scheduled program. Lastly, according to PBS, the use of telephone lines to deliver programming was "incapable of producing high-fidelity sound," especially for musical programs such as concerts, so they started to look for an alternate method of distributing programming.
PBS began to inquire about the use of satellite for program distribution dating back to 1971. PBS quickly discovered the benefits satellite distribution would have on their operations. A satellite-based interconnection system would allow improved video and audio quality. Unlike the terrestrial-based system, where quality degrades the farther the signal travels, programs fed via satellite would suffer no loss in quality; each station would receive the same copy of the program. A satellite-based system would also allow for more than one program feed.
Digital Audio for Television (DATE) In 1973, PBS, along with Digital Communication Corp, developed a prototype audio system that would allow for high-quality audio to be transmitted alongside television programming. This system consisted of four 15-kHz audio channels that would be "multiplexed" and transmitted via a "5.5-KHz subcarrier located above the video". This system would become known as DATE (Digital Audio for TElevision). What made date intriguing was that it would allow for high-quality stereo audio, in addition to quadraphonic audio, analog data, and the option to include a Secondary Audio Program (SAP) channel. PBS said that DATE "produces no perceptible picture degradation" and that the audio quality "is maintained at a 70-dB signal-to-noise ratio". Using DATE, according to PBS, would also lead to decreased operational costs and the need for separate facilities that would be needed to transmit high-quality audio. To receive DATE signals, stations required both an encoder and decoder.
While the DATE system sounded promising, PBS said that the system was never widely adopted due to "high cost". Decoders for the DATE system cost up to $11,000 in the mid-1980s. PBS recommended that a station purchase at least two decoders, one of these acting as a backup unit. By 1987, "less than half of PBS's member stations" could adequately decode and broadcast DATE audio signals due to these high costs and the lack of available parts.
1978: Preparations for the Second-Generation, Satellite-Based Interconnection System In August 1976, PBS submitted their proposal of a satellite-based interconnection system to the FCC. In December 1976, PBS, as well as NPR, received approval from the FCC regarding this proposal. PBS reached an agreement with Western Union in June 1976 to lease three full-time C-band transponders on the Westar 1 satellite, at orbital position 99°W, for a period of seven years (until 1985) at a cost of $800,000 per year; if PBS were to add a fourth transponder, this would cost $750,000 per year. The total cost of implementing this system was around $39,500,000 ($226,854,261.86 adjusted for inflation as of March 2026). The details of the contract with Western Union follow:
As stated earlier, PBS would least three transponders at a cost of $800,000 per year, with the option to add a fourth transponder, lowering the cost to $750,000 per year. PBS would be guaranteed replacement transponders on Westar 1 or, if the satellite failed, replacement service on Westar 11 at orbital position 123.5ºW. Western Union guaranteed that all public televisions stations would reliably receive PBS's signals. There were no limits on the type of traffic PBS could uplink to satellite, meaning they were free to uplink various types of content such as television programming and data. Western Union agreed to "[t]echnical performance limits" for each transponder PBS leased. There were maximum limits on the overall movement and attitude of each satellite; this way, there would be no need to install "automatic satellite tracking capability." PBS was granted free use of the transponders during implementation of the system, but only up to 300 hours. The free use of the transponders allowed public television stations to test signal reliability during installation of their ground stations. Western Union would provide PBS with free engineering assistance during implementation of the system.
June 1977–March 1, 1978: The Implementation Phase Implementation of the system began in June 1977. During implementation, the terrestrial interconnection system would continue to be operational. The first step was constructing a Main Organization Terminal (MOT) as the soon-to-be PBS SOC. Planning of the construction of the MOT took three years. The MOT was completed by the end of January 1978 Throughout 1977 and 1978, satellite dishes (ground stations) were installed at each public television station around the country. Western Union split the country into various segments during the implementation phase. The first two segments were based in the Southeastern and Southern portions of the country. Construction in Segment I was completed by February 1, while Segment II was completed by mid-April. WFSU (Orlando, Florida) was the first station to have a ground station installed. Segment III consisted of stations in the West Coast and Segment IV consisted of stations in the Rocky Mountains. Terrestrial service at each segment would continue for one month after the installation of the ground stations.
March 1, 1978–December 1978: The Launch Phase and End of the First-Generation Interconnection System