On November 2, 1936 the BBC began airing high definition television, and celebrations of this milestone are taking place this month.
Alexandra Palace was chosen as the location because its high location was thought to be suitable for the transmitter tower and because it was cheaper and quicker to convert an existing building than to build a new one.
Having the transmitter and studios in the same building caused some problems, such as radio transmissions interfering with electronics of cameras.
Two services were tested. The system designed by John Logie Baird, who had been at forefront of television development, was tried in one studio with the Marconi-EMI system in another. A coin toss decided that the pilot programme would be transmitted on the Baird system first, and then on the Marconi-EMI system following a brief pause - so that there was a repeat show on the first day.
After three months it was decided to use the latter system, which allowed more cameras - which could be moved on wheels - to be used.
The BBC reported that Rebecca West said Baird was "doomed to be the man who sows the seed but does not reap the harvest".
A BBC video reported that names once considered for television included phototelegraphy, seeing by wireless, and electric telescope.
Only about 20,000 homes around London were able to receive shows at first, and Digital Spy reported that broadcasting only took place for two hours.
In 1939, with war looming, the transmitters were shut off and did not resume operation until 1946.
Much of the original structure still exists at Alexandra Palace, which is the 75th anniversary of TV with (free but sold-out) tours, displays and demonstrations on November 5 and 6.
“The 75th anniversary of the world’s first television broadcast by the BBC from Alexandra Palace is a fantastic opportunity to reflect on London’s role as a pioneer and innovator," London Mayor Boris Johnson said in an Alexandra Palace press release. "With master-planning underway to regenerate the iconic Alexandra Palace site for future generations to enjoy, it is a chance to celebrate the great achievements of public service broadcasting and also discover how world-renowned colleges like Ravensbourne are helping to shape the future of television and digital media.”