The BBC National Programme was a UK radio broadcasting service which was on the air from March 9, 1930 – when it replaced the earlier BBC radio station 5XX – until September 1, 1939, when it was subsumed into the BBC Home Service, two days before the outbreak of World War II.
When the British Broadcasting Company (later to be nationalised as the British Broadcasting Corporation) began transmissions on November 14, 1922, the technology for both national coverage and joint programming between transmitters did not exist – transmitter powers were generally in the region of 1 kilowatt (kW).
From July 9, 1924, however, the company began experimenting with higher power long wave transmissions from the Marconi company’s site near Chelmsford in Essex, using the call sign 5XX. The experiments proved successful and on July 27, 1925 the Chelmsford long wave transmitter was relocated to a more central site at Borough Hill near Daventry in Northamptonshire. This provided a “national service” of programmes originating in London, although it remained somewhat experimental and was supplementary to the BBC’s locally based services, including its main London station, 2LO.
On August 21, 1927, the BBC opened a high power medium wave transmitter at the Daventry 5GB site, to replace the existing local stations in the English Midlands. That allowed the experimental long wave transmitter 5XX to provide a service programmed from London for the majority of the population. This came to be called the BBC National Programme.
Initially the national programme was transmitted on 187.5 kHz long wave but this was later changed, with the opening in 1934 of a new high-power long wave transmitter site at Droitwich, to 200 kHz, which was to remain the BBC’s long wave frequency until 1978, when it was moved slightly to 198 kHz. Medium wave transmitters were used to augment coverage.
Upon the outbreak of World War II, the BBC closed the Regional and National Programmes and replaced them with a single channel known as the BBC Home Service. The main transmitter network was synchronised between just two groups, using 668 and 767 kHz, each of which could be turned off during air raids to prevent its signals being used as navigational beacons (with listeners required to retune in such an event to a low-powered single-frequency network on 1474 kHz).
On July 29, 1945, within 12 weeks of VE Day, the BBC reactivated the Regional Programme, but retained the name “BBC Home Service”. On the same date, the BBC Light Programme was launched, taking over the style and much of the function, as an entertainment channel, of the BBC Forces Programme (which had begun broadcasting in 1940), as well as the Droitwich 200 kHz longwave frequency which had been used by the pre-war National Programme.