Type 6 Mark 4 Mod 3 Airborne Radar

Photograph of captured B5N Kate with surface search radar
U.S. Navy. Via Francillon (1979)
Photograph of Yagi nose antenna of Type 6 mark 4 Mod 3 airborne radar
National Archives. Via Nakagawa (1997)


200 cm
Pulse length
10 microseconds
Peak powe
3 kW
Range 75 nautical miles (130 km)
Various; see description below
A scope
240 lb
110 kg
Production: About 2000. Available from 1942-8 and Installed on a number of G4M "Betty", H8K "Emily", and B5N "Kate" aircraft, particularly after 1944.

The Type 6 Mark 4 Mod 3 radar was used with various antenna configurations on a number of Japanese aircraft. Few units were so equipped before 1944 and the first example was captured by the Allies in May 1944 at Hollandia. The set was heavy enough that torpedo bombers equipped with it were unable to carry a torpedo as well, making them dedicated search aircraft.

The antenna configurations seems to have varied with platform. The installations on multi-engine aircraft used a four-element Yagi antenna in the nose for the transmitter and two reflected dipoles on the wings for the receiver. On torpedo bombers, where a nose antenna was impractical, a fuselage dipole array was apparently used instead. The fuselage dipole array had the significant weakness that it could not search the area head ahead of the aircraft, so that aircraft equipped with the radar had to approach a target obliquely to maintain radar contact.

The radar was plagued by corona discharge at high altitude and by sea return. The Yagi antenna was less susceptible to this effect.


Friedman (2013)

Grunden (2005)

Guerlac (1987)

Nakagawa (1997)

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