generate questions: The two systems were to run on a trial basis for six months; early television sets supported both resolutions. However, the Baird system, which used a mechanical camera for filmed programming and Farnsworth image dissector cameras for live programming, proved too cumbersome and visually inferior, and ended with closedown (at 22:00) on Saturday 13 February 1937.
For how long did the BBC alternate different broadcasting systems? {sep_token} What kind of camera was used to broadcast live shows under the Baird system? {sep_token} When was the Baird system officially abandoned?