Naxos or FuG 350 …
In the early stages of WW2 German radar technology was ahead of the Allies, using wavelengths down to half a metre. However, expecting a short war Hitler stopped further development.
The development of the Magnetron and centimetre wavelengths took the enemy by surprise. The discovery of H2S radar in a Stirling bomber that crash landed gave away the secret. One response was to develop a warning and homing receiver to work on the 10 cm wavelength under the name Naxos or FuG 350.
Naxos was effectively crystal receiver using a rotating aerial feeding a circular display. The aerial was unusual being two polystyrene rods.
A signal appeared as a blob on the bearing of the transmitter. With a range approaching 100 miles it was very effective.
When a Naxos set was discovered in a captured German nightfighter, it led to restrictions on the use of H2S
