Tag Archives: Post Office Research Station

TV detector vans – an urban myth?

by Jenny Karlsson, PR & Communications Officer

Since they were introduced in the 1950s, a lot of controversy has surrounded TV detector vans. Many people were (and still are) convinced that they didn’t work or never even existed. A new BBC Radio 4 programme on Saturday 13th June will set out to investigate this urban myth, drawing upon files from The British Postal Museum & Archive (BPMA).

An annual licence fee of 10 shillings was first introduced under the Wireless Telegraphy Act in November 1923 to cover radio sets. The first combined Radio and TV licence was introduced in 1946, costing £2 (the equivalent of £57 in 2006) and covering the monochrome-only single channel BBC television service, and the licences were initially issued and administered by the General Post Office (GPO).

As part of the Post Office campaign to track down users of unlicenced sets, the first TV detector van was constructed in 1952. The detection equipment in the van had been developed at the radio experimental laboratories of the Post Office in Dollis Hill, London. The van was then demonstrated in front of then Postmaster General, Lord De La Warr and Assistant Postmaster General Mr Gammans. In articles covering the demonstration, the Postmaster General was quoted as saying: “The equipment, which is suitable for fitting in a standard Post Office Radio Interference van, enables the majority of working television receivers on both sides of the road to be detected, and the houses containing the receivers to be located, as the vans move along the road”.

In May this year BBC Radio 4 visited the BPMA Search Room in London to conduct research and do recordings for a show about TV detector vans. The aim of the show is to expose the myths about TV detector vans, and is part of a series of programmes in which the comedian Steve Punt (famous from the sketch duo Punt & Dennis and shows like The Mary Whitehouse Experience) investigates urban myths. When the TV detector vans were introduced, many people were convinced that they were empty inside or that the equipment didn’t really work. The BBC team also went out to the BPMA’s Museum Store in Debden, Essex, to have a look at the TV detector van that is on show there. Chris Taft, BPMA Curator and Helen Dafter, BPMA Archivist were both interviewed for the programme.

The BPMA holds a range of records relating to TV licensing and detector vans, such as press cuttings, memos referring to difficulties caused by iron railings and iron girdles, and details of experimental combs, including number of TV sets detected, number of calls made and the results of these calls.

TV licensing was also promoted by poster campaigns. The earliest of these posters held in the archive is from 1951 and states: ‘Don’t be a pirate – A Television and Sound Licence costs £2 for a year’. In reference to this, the prototype detector van was known to some members of the press as “The Jolly Roger”.

Dont Be A Pirate! A Television and Sound Licence costs £2 for a year

Don't Be A Pirate! A Television and Sound Licence costs £2 for a year

Why not listen to the show and make your own mind up about TV detector vans?

BBC Radio 4: Punt Pl
Saturday 13th June 10:30am – 11.00am
The show will be available for one week after the broadcast on the BBC’s iPlayer service.

Colossus and D-Day

65 years ago today General Dwight D. Eisenhower and his staff met to discuss the Normandy landings, or D-Day. The landings had been planned for some time and their success depended on good weather for the crossing and landing, and minimal resistance from German troops so that the Allies could gain a foothold.

Weather conditions had been too poor for a landing in early June 1944, but chief meteorologist James Martin Stagg forecast an improvement on 6th June. This weather forecast is usually cited as the deciding factor in Eisenhower’s decision to set D-Day for 6th June. However, Eisenhower is said to have received another piece of information during that meeting which was just as crucial, and he had the skill and inventiveness of the Post Office Research Station, Dollis Hill to thank for it.

Post Office engineers re-wire a telephone exchange after an air raid. Post Office telephone engineers developed the first programmable electronic computer during the 2nd World War.

Post Office engineers re-wire a telephone exchange after an air raid. Post Office telephone engineers developed the first programmable electronic computer during the 2nd World War.

Before the war Post Office engineer Tommy Flowers and his team at Dollis Hill had worked in switching electronics, exploring the possibilities for electronic telephone exchanges. But by the early 1940s they were helping the British code-breaking team at Bletchley Park. Colossus, later recognised as the world’s first programmable electronic computer, was their greatest achievement.

Colossus was primarily developed to decipher the Nazi Lorenz codes, high-level encryptions used by senior personnel, rather than the more famous Enigma codes used by field units. Computer technology was in its infancy in the 1940s and when in early 1943 Flowers proposed the machine, which would run on 1800 valves (vacuum tubes), there was great scepticism that it would work as until that point the most complicated electronic device had used about 150 valves.

But by December 1943 Colossus Mark 1 was working and it was soon moved to Bletchley Park, where it was able to break German codes within hours. An improved version, Colossus Mark 2, using 2400 valves, was unveiled on 1st June 1944, four days before Eisenhower made his decision about D-Day.

An essay by Flowers published in Colossus: The Secrets of Bletchley Park’s Code-breaking Computers describes the crucial meeting between General Eisenhower and his staff held on 5th June 1944. During that meeting a note summarising a recent Colossus decryption was handed to Eisenhower. It confirmed that Hitler was aware of troop build-ups in southern England, but would not be sending extra troops to Normandy as he was certain that Allied preparations were a hoax. This information was said to have convinced Eisenhower that the Normandy landings should take place the next day.

But whether it was the weather forecast or the Colossus decryption which tipped the balance in favour of 6th June, Flowers and the Post Office Research Station team made a remarkable advance in computer technology. By the end of the war 10 Colossus Mark 2 computers were in use at Bletchley Park, providing vital information to Allies forces, which certainly reduced the length of the war. After the war Flowers and his team returned to their work in switching, later pioneering all-electronic telephone exchanges. Their ingenuity was only recognised in the 1970s when restrictions on the Colossus project under the Official Secrets Act were lifted.