Marconi Direction Finding equipment in WW-1
Early Direction Finding (D/F) equipment using “soft electronic valves” and a Bellini-Tosi directional system was secretly developed by the Marconi Company in Chemsford just before WW-1, and stations were set up during the war across the British Isles and the Western Front. The purpose was to obtain information regarding the location of Zeppelins and submarines by detecting the radio frequency transmissions that they made. Direction Finding played a crucial role in the outcome of WW-1. A tent was used to house the Marconi Direction Finding Equipment to detect Zeppelins. This photograph was taken in 1916...
The first wartime direction-finding stations were tested in 1915, and weekly maps based on D/F information were drawn for Military Intelligence. Initially, these showed German wireless positions; soon they would also indicate movement of trench wireless units and therefore troops, of Zeppelin dirigibles and other enemy aircraft. The equipment picked up both the signals from radio transmitters and noise generated by the coil and spark plugs of engines to provide early warning position and direction information, but as the enemy realised the need to minimise radio transmissions and fit ignition noise suppressors to the engines their usefulness dwindled.
Initially the D/F installations were carried on horse-drawn wagons and set up in tents, but the Marconi Company developed portable sets housed in automobile trucks. By 1916 a large number of secret stations which utilised the equipment were in use. By 1916 the coastlines of Britain were covered by a network of Direction Finding stations. As the Stow Maries and Goldhanger flight stations were the nearest Zeppelin chasing stations to Maconi’s research establishment at Chelmsford they would have been closely involved with this very secret activity.
A BT phone card produced to commemorate Marconi’s centenary
L48 was shot down by flying Officer L.P. Watkins after taking off from Goldhanger