Type 271 Surface Search Radar

Photograph of Type 271 radar antenna

Naval History and Heritage Command #NH-80532

Cropped by author


Wavelength 10 cm
Pulse Width 0.7 or 1.5 microsecond
Pulse Repetition Frequency     
500 Hz
Scan Rate
Manual; approximately 2 rpm
Power 7 kW
Range 11 nautical miles (20 km) battleship
10 nautical miles (19 km) heavy cruiser
8 nautical miles (15 km) destroyer
6 nautical miles (11 km) frigate
3.5 nautical miles (6.5 km) PT boat
3 nautical miles (6 km) submarine
Double cheese
A scope. Plan Position Indicator on later models
Hundreds of sets from 1941 on

The Type 271 was an early British naval sea search radar, available when war broke out in Europe. It was equipped initially with an A-scope display. Later versions had a PPI display. It was fitted primarily to escort vessels (corvettes and frigates). It used a "double cheese" antenna enclosed in a Perspex (plexiglass) "lantern". The antennas were steered using an automobile steering wheel from an operator's station directly below the "lantern". This arrangement minimized the length of the coaxial cables used in this very early microwave set.

An improved version, Type 271Q, was introduced in 1943 and had a much more powerful magnetron (100 kW) and correspondingly greater range. The Type 272 was an unsuccessful attempt at a refined version for destroyers and cruisers, while Type 273 was a successful version for cruisers and battleships.


Buderi (1998)

Friedman (1981, 2006)

HMCS Sackville Web Site (accessed 2010-4-15)

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