Lichtenstein (radar)

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Ju 88 with radar antenna of FuG 202 "Lichtenstein"
A Messerschmitt Bf 110 G night fighter in the RAF Museum in Hendon, with the medium version of the “deer antler” antenna for use with the FuG 220 “Lichtenstein SN-2” radar.

The Lichtenstein device, a development by Telefunken , was one of the first on- board radar devices available to the German Air Force during World War II .

history

The first tests took place in mid-1941. In 1942 the first version was FuG 202 ( Fu NK G et up instrument) Lichtenstein B / C used. It worked on a wavelength of 75 cm (490 MHz in the lower UHF band) and required relatively large antennas, which quickly gave rise to the nickname “mattress”.

The on-board radar enabled night fighters of the German Air Force to attack enemy bombers. At first they used conventional methods and later, when these became ineffective due to the reactions of the opponents, the night hunting method "Tame Sau" .

In 1943 an improved version was delivered as FuG 212 Lichtenstein C-1 with a larger and wider detection area. By this time the British had already tried methods of jamming radars. After a Ju 88 C-6 night fighter with a FuG 202 B / C landed in England in April 1943 , the British learned details about the German aircraft radar. The length of the aluminum strips (called chaff in Germany and window in England ) with which the FuG 202 B / C could be disturbed resulted from the wavelength . This made the on-board radar system largely useless for a few crucial weeks.

As early as February 1942, during Operation Biting , the British captured parts of the German “Würzburg” radar system and thus found out its wavelength. Since then they have disrupted this system with 26.8 cm long chaff.

Late in 1943, the Air Force began using the improved FuG 220 Lichtenstein SN-2 device, which operated on the lower frequency of 90 MHz at the lower end of the VHF broadcast band. The device was far less sensitive to electronic interference measures, but because of the longer wavelength , the antenna system had to be significantly enlarged, which reduced the top speed of the night fighter by more than 50 km / h. This antenna system became known by the nickname "deer antlers". The first SN-2 devices had a large minimum distance of 500 m to the target, which made an additional smaller antenna on the aircraft nose and a second Lichtenstein B / C or C-1 necessary for the distance range below 500 m. In the spring of 1944, improvements to the SN-2 made it possible to cover the lower distance range.

On April 28, 1944, a Bf 110 with the identification C9 + EN landed with the Lichtenstein radar after glare from headlights that could not be shaken off on the Dübendorf in Switzerland. The radar was immediately examined by specialists from ETH , including in field tests, with the aircraft being pulled onto a ramp in order to point the radar into the air. After the Germans had also considered an attack on Dübendorf, it was agreed to destroy the aircraft under German supervision.In return, Switzerland was able to acquire 12 type Bf 109G fighters , and the incident also made it easier for Switzerland to purchase two Würzburg radars that had been prepared for a long time.

On July 13, 1944, the improved version of the SN-2 fell into the hands of the Allies after a fully equipped Ju 88 G-1 mistakenly landed at RAF Woodbridge in south-east England due to a navigation error . The crew noticed the mistake too late; she no longer had time to destroy the radar device and the friend-foe recognition device ( "first product" ). Also on board this Ju 88 was the FuG 227 Flensburg, previously unknown to the Allies, for locating emissions from the Monica radar installed in British bombers . This mistake by the crew led to the immediate shutdown of all Monica radars and the blocking of some frequency ranges of the SN-2. German night hunters then received a new version of the “deer antler” antenna with dipoles inclined by 45 degrees for better reception of the frequencies that were not blocked.

Towards the end of 1944, the Morgenstern antenna was developed, which was finally small enough to be installed in the aircraft nose of the Ju 88 under a wooden cover. The SN-2 was further developed to the FuG 228 Lichtenstein SN-3 ; but it was no longer used on a large scale. It took the Allies some time to develop disruptive measures against the SN-2; from the end of 1944 / beginning of 1945 they were successfully feasible.

A new system with a wavelength of 9 cm was the FuG 240 “Berlin” , which was based on the technology of a captured Allied cavity magnetron . This system has been tested in some Ju 88 G-6s; 25 copies were produced by the end of the war.

The British night fighters de Havilland DH.98 Mosquito were equipped with a device called Serrate , which enabled them to track the German night fighters on the basis of radio emissions from the Lichtenstein B / C, C-1 and SN-2 devices. A system called Perfectos for querying the German “Erstling” friend-enemy identifier was also on board the Mosquitos.

gallery

Technical specifications

Type FuG 202 FuG 214/216 FuG 220
Transmission frequency 410-540 MHz 335-362 MHz 90 MHz
Receiving frequency 479-499 MHz 335-362 MHz 90 MHz
Pulse power 450 W 450 W 2000-2500 W
Pulse duration 1 μs 1 μs 1 μs
Pulse frequency 2700 Hz 2700 Hz 292/295/298 Hz
Opening angle (-3 dB) 30 ° 35 ° laterally, 20 ° high, 55 ° deep
Bearing accuracy 3 °
Power supply 24 V DC, 8 A unknown
Antenna gain 13 dB 5 dB
Weight 55 kg per set 55 kg per set
Tube assembly 12 × RV12P2000 , 2 × RS394, 7 × LV1, 5 × LD2, 2 × LG1, 5 × LD1
Range 0.2-4 km 0.2-4 km 0.5-5 km

German sources partly deviate from these values.

See also

literature

Web links

Individual evidence

  1. ↑ Note alluding to the spring core of a mattress
  2. ^ Theo Wilhelm: Almost an attack on Dübendorf
  3. ↑ Hans H. Jucker: History of the military radar applications in Switzerland
  4. ^ Hitler's secret night fighter in flames , NZZ, May 29, 2011
  5. ↑ TME 11-219 Directory of German Radar Equipment