Context: 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. 

Question: For how long did the BBC alternate different broadcasting systems?
Answer: six months

Question: What kind of camera was used to broadcast live shows under the Baird system?
Answer: Farnsworth image dissector

Question: When was the Baird system officially abandoned?
Answer: 13 February 1937

Question: How long did two systems run on a trial basis for?
Answer: Unanswerable

Question: What type of camera did the Baird image dissector use?
Answer: Unanswerable

Question: What ended on Saturday 17 February 1933?
Answer: Unanswerable