Alexandra Palace is the historic transmitter site where the BBC first
carried out its experimental television test transmissions from 1936 to
1937. This is when the testing of two television systems took
place between John Logie Baird's 240 line mechanical system and
Marconi/EMI's 405 line electronic scan system. The
Marconi/EMI system won the support of the BBC, and thus the Baird
system was discontinued in February 1937. BBC Television
programmes continued from 1937 until September 1939 when war broke
out. The Second World War finished in 1945 and television
broadcasts recommenced in June 1946.
The television signals from Alexandra Palace in the 1940's were
broadcast on 41.5 MHz (Band I v.h.f) with a power of 3 kW.
The 405 line television transmissions from Ally Pally, as the famous
station became known, were later closed and transferred to Crystal
Palace. The 405 line television system as a whole was closed down
in the early 1980's and
today the famous building is home to a low power u.h.f. analogue PAL
colour television relay transmitter - which itself may be closed down
with the arrival of the digital terrestrial television (DTT)
Alexandra Palace is also home to DAB digital radio transmitters, and
two low power local radio stations - using 103.3 MHz FM (LGR - London
Greek Radio) and 107.1 MHz FM (Choice FM).