FuG 240 Berlin

By 1943 a series of efforts and lucky intercepts had allowed the Royal Air Force to introduce jammers, which interfered with the AI radar's operation.

The SN-2's lower frequency range required enormous eight-dipole Hirschgeweih (stag's antlers) antennas, which created so much drag that aircraft were slowed by some 50 km/hour.

The Royal Air Force's first Airborne Intercept radars operated in the 1.5 meter band and featured antennas similar to their later German counterparts.

The magnetron efficiently generated microwaves from a device the size of a coffee tin, lowering operational wavelengths from the several-meter range to less than 10 centimeters.

Instead of simply using a smaller Yagi antenna, the system was paired with a new parabolic dish which allowed for conical scanning.

This was of great use to RAF Bomber Command's efforts, and an intense debate broke out over whether to allow its use over continental Europe.

This work led to the FuG 350 Naxos device, a radio receiver using a DF loop for an aircraft installation, covered with a teardrop-shaped fairing and tuned to the H2S frequencies, that was used to track the Pathfinders in flight.

The captured magnetron was sent to Berlin and a group assembled from the German electronics industry met at the Telefunken offices to discuss it.

The N-4 was a further development of the N-3; it rotated the antenna in the horizontal plane under an FuG 350 Naxos-antenna style teardrop housing atop the aircraft fuselage.