Editing Stereophonic sound (section)

====FM standards====
[[File:Scott350.jpg|thumb|[[HH Scott]] Model 350, c. 1961: the first FM stereo tuner sold in the U.S.]]

The Zenith-GE [[Pilot signal|pilot-tone]] stereo system is used throughout the world by [[FM broadcasting]] stations.

It was eventually determined that the bandwidth assigned to individual FM stations was sufficient to support stereo transmissions from a single transmitter. In the United States, the FCC oversaw comparison tests, conducted by the National Stereophonic Radio Committee, of six proposed FM standards. These tests were conducted by [[WLTJ|KDKA-FM]] in Pittsburgh, Pennsylvania during July and August 1960.<ref>{{cite web |title= Commentary: Dick Burden on FM Stereo Revisited |url= http://www.rwonline.com/article/812 |archive-url= https://archive.today/20120910150332/http://www.rwonline.com/article/812 |url-status= usurped |archive-date= 2012-09-10 |date= February 1, 2007 |publisher= Radio World |access-date= February 10, 2021 }}</ref> In April 1961 the FCC adopted stereophonic FM technical standards, largely based on a Zenith-General Electric proposal, with licensed regular stereophonic FM radio broadcasting set to begin in the United States on June 1, 1961.<ref>[https://archive.org/stream/broadcastingtele60unse_0#page/n442/mode/1up/ "Finally, FCC Okays Stereo"], ''Broadcasting'', April 24, 1961, pages 65–66.</ref> At midnight in their respective time zones on June 1, General Electric's [[WRVE|WGFM]] in Schenectady, New York, Zenith's [[WUSN|WEFM]] in Chicago, and [[KKLQ (FM)|KMLA]] in Los Angeles became the first three stations to begin broadcasting using the new stereo standards.<ref>[https://archive.org/stream/broadcastingtele60unse_0#page/n1189/mode/1up "Three fms meet date for multiplex stereo"], ''Broadcasting'', June 5, 1961, page 58.</ref>

Following experimental FM stereo transmissions in the London area in 1958 and regular Saturday morning demonstration transmissions using TV sound and medium wave (AM) radio to provide the two channels, the first regular BBC transmissions using an FM stereo signal began on the [[BBC Third Programme]] network on August 28, 1962.<ref>[https://www.bbc.co.uk/historyofthebbc/anniversaries/august#heading-start-of-experimental-stereo-broadcasting-28-august-1962 Start of experimental stereo broadcasting 28 August 1962] {{Webarchive|url=https://web.archive.org/web/20181119060935/https://www.bbc.co.uk/historyofthebbc/anniversaries/august#heading-start-of-experimental-stereo-broadcasting-28-august-1962 |date=November 19, 2018 }}, BBC</ref>

In Sweden, [[Televerket (Sweden)|Televerket]] invented a different stereo broadcasting system called the ''Compander System''. It had a high level of channel separation and could even be used to broadcast two separate mono signals{{snd}} for example for language studies (with two languages at the same time). But tuners and receivers with the pilot-tone system were sold so people in southern Sweden could listen to, for example, Danish radio. At last Sweden (the Televerket) decided to start broadcasting in stereo according to the pilot-tone system in 1977.