Part 3 of 8: War and Peace
The new decade is barely six weeks old when Australian scientist Professor (later Sir) Mark Oliphant is involved in development of one of the greatest inventions of the war, the cavity magnetron. It revolutionises radar, thanks to its production of 10cm radio-waves and delivers a quantum-change in radar-image resolution. TV engineer Alan Blumlein and others take the cavity magnetron and by 1942, indicator lines and points on a cathode-ray tube begin to display terrain and map-like images from the air. What’s more, while Blumlein’s contribution in British television went ‘lights-out’ for the duration of the war, television itself would still have one more vital ‘defensive’ role to play.
The Battle of the Beams
Even early in the war, radio played a role well beyond communication. Radionavigation aids, such as the Lorenz blind-landing radio receivers, were in use since 1937 to help navigate pilots toward a safe landing during poor weather. Using tightly-directed beams of Morsecode ‘dots’ and ‘dashes’, pilots weaved towards the ‘equi-signal’ of the two beams to be sure of a correct approach to the runway.
By 1940, the German Luftwaffe redesigned the Lorenz system into navigation aids for their bombers. One of the systems employed was known as ‘Y-Gerat’ or ‘Wotan’ (see the excellent 1977 BBC Series ‘The Secret War’ – Part 1). It featured a
