Jagdschloss captured in 1945 while still under construction
|
|
Country of origin | Germany |
---|---|
Introduced | 1943 |
Type | Early warning radar |
Frequency | 129–165 MHz |
PRF | 500 per second |
Pulsewidth | 1μs |
Range | 80 kilometres (50 mi) |
Azimuth | 360° |
Power | 30 kW |
Jagdschloss, officially the FuG 404, was the designation of a German early warning and battle control radar developed just prior to the start of World War II. Although it was built in limited numbers, Jadgschloss is historically important as the first radar system to feature a plan position indicator display, or "PPI". In Germany this type of display was referred to as "Panorama". It is named for Jagdschloss, a hunting lodge.
The PPI effort started fairly early in the history of radar; Hans Hollmann filed a patent for the basic concept in 1936. At that time development of GEMA's other radars, notably the Freya, took priority, and work on the system did not start until 1939. By this time, radar development had progressed to the point were a prototype could be constructed by re-using systems from various production radars.
A prototype system was built south of Berlin, known as the Tremmen Radar Tower. It mounted a large antenna consisting of two rows of four half-wave dipoles aligned horizontally, rotating on a shaft located at the top of the tower. It was found that at least five pulses needed to be returned in order for the target to become visible on the scope, so the rotation rate of the antenna was adjusted to synchronize with the pulse repetition frequency of the radar. The radio equipment was taken from the Wassermann and Freya units, and operated on a basic wavelength of 2.4 m (~125 MHz).
Although the system demonstrated its utility, further units were not ordered until the fall of 1942, likely due to the increasing tempo of RAF Bomber Command's night offensives at that time. Production Jagdschloss units were larger than the original prototype, with an antenna 24 m (79 ft) wide and 3 m (9.8 ft) tall. New electronics were built for the production units, operating on one of two bands, the A band on 1.2-1.9 m or the B band on 1.9-2.5 m. The first production sets were delivered by Siemens & Halske at the end of 1943, and when production ended in April 1945 a total of 80 units had been delivered.