Читать книгу Engineering Hitler's Downfall - Gwilym Roberts - Страница 40

Operating out of some 30 separate stations, personnel from the Royal Signals and other agencies listened into German wireless traffic; later from stations in India and elsewhere in the Far East, they listened into Japanese signals. Many amateur (‘ham’) radio operators supported the work of the ‘Y’ stations, being enrolled as ‘Voluntary Interceptors’. Much of the traffic intercepted by these stations was recorded by hand and sent to Bletchley Park on paper by motorcycle couriers or, subsequently, by teleprinter over Post Office landlines. A large house called Arkley View on the outskirts of Barnet acted as a data collection centre at which traffic was collated and passed to Bletchley Park. It also acted as a ‘Y’ station.

In addition to wireless interception, specially constructed ‘Y’ stations also undertook High Frequency Direction Finding (HF/DF, known colloquially as ‘Huff Duff’) on enemy wireless transmissions. This became particularly important in the Battle of the Atlantic (1939–1945), where locating the positions of U-boats became a critical issue. Admiral Dönitz told his commanders that they could not be located if they limited their wireless transmissions to under 30 seconds, but skilled HF/DF operators were able to locate the origin of their signals in as little as six seconds.

The land-based DF stations preferred by the Allies operated on the Adcock antennae system, which consisted of a small central operators’ hut surrounded by four 10-metre-tall aerial poles, usually placed at the four compass points. Aerial feeders ran underground and came up in the centre of the hut; these were connected to a direction-finding goniometer and a wireless receiver that allowed the bearing of the signal source to be measured. In the UK some operators were in underground metal tanks. These stations were usually located in remote places, often in the middle of fields. Traces of Second World War D/F stations can be seen as circles in the fields surrounding the village of Goonhavern in Cornwall.