In 1938, unusual atmospheric conditions enabled a few minutes of BBC television to be picked up in the United States. An early cine camera, pointed at a TV set, captured the footage that includes BBC announcers, a drama, and the BBC station identification. From the Alexandra Palace Television Society and posted on Archive.org:
It was made at a time when no technology existed to record live broadcasts directly. Video tape was not perfected until the late 1950s and "telerecording", the quality copying with a cine camera mounted in front of a television screen was not developed until after the Second World War. There are other recordings from the pre-war era, but they are all cine film shot from a camera alongside the television lens, or as in the case of the Demonstration Films, recreated scenes in a shot in a film studio.
The American recording was shown on 26 June 1999 at the refurbished National Museum of Photography, Film and Television in Bradford.
Mr Emmerson, 50, a freelance researcher and writer on the television industry, said: "Rumours of a recording existing in America have circulated for years, but no one had ever got to the bottom of them. It was known that about this time there had been tremendous sun spot activity, which had a dramatic effect on the ionosphere. Broadcasts from the BBC Television Station at Alexandra Palace travelled less than 30 miles, but because of the sun spots they were being bounced off the ionosphere and picked up 3,000 miles away on the East Coast of America."
"There were reports that RCA, which was working on its own television system, had conducted an experiment to film the broadcasts. About five years ago I decided to check it out, but with no success. RCA could not trace anything, nor could anyone else. Then last year a friend at the American Vintage Wireless Collectors' Society agreed to mention it in their magazine."
One of the respondents was Maurice Schecheter, who worked in a New York television studio. He had a collection of television material and among it was one of the RCA recordings on 16mm film.
"He cleaned it up digitally and transferred it to a video cassette for me," Mr Emmerson said. "I was astounded. This was the oldest and probably the only example of live high-definition television from the pre-war period."