The station airs PBS programs that are not aired by WGBH-TV as well as additional supplemental programming. Reruns of the previous night's programming either from WGBH-TV or from WGBX-TV itself also makes up part of channel 44's programming schedule. WGBX also carries the digital subchannels owned by the WGBH Educational Foundation; this enables WGBH to maintain a full 1080ihigh definition picture resolution on its main channel 2 signal, without any loss in visual quality.
This section requires expansion with: further detail on the history of WGBX-TV. (June 2013)
The station initially existed as a construction permit for WJDW-TV, a commercial station co-owned by television producer Jack Wrather and his business partner, Maria Helen Alvarez. In 1965, Wrather and Alvarez donated the license to WGBH Educational Foundation, in which WGBH used to launch its secondary educational station. WGBX-TV first signed on the air on September 25, 1967; its transmitter has been located in Needham (on a broadcast tower that is now operated by CBS Corporation, and is used by some of the Boston markets' commercial television stations, including CBS-owned WBZ-TV), WGBX's current digital transmitter shares the master antenna at the very top of the tower with the commercial stations. The now defunct analog signal maintained a separate antenna on a lower portion of the tower that was shared with WGBH's digital transmitter.
The X in its callsign stands for "Experimental", as WGBX (more primarily in the 1970s) was home to programming that was given a trial run on the lower-rated UHF signal before possibly moving onto the more-established WGBH-TV. Such Eastern Educational Network imports from the United Kingdom as Doctor Who were seen first or more frequently on WGBX, and one late 1970s local "nightclub"-style variety show, Club 44, proved popular enough to be moved over to WGBH and retitled The Club.
WGBX-TV shut down its analog signal, over UHF channel 44, on April 23, 2009, two months prior to the official date in which full-power television stations in the United States transitioned from analog to digital broadcasts under federal mandate. The station's digital signal remained on its pre-transition UHF channel 43. Through the use of PSIP digital television receivers display the station's virtual channel as its former UHF analog channel 44.