Hohentwiel (radar)

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Fw 200 with radar antenna of the FuG 200

The FuG 200 "Hohentwiel" was a radar device of the German Air Force during World War II . It was developed from 1938 by the C. Lorenz company in Berlin. The device was originally planned for the Air Force tender for the new FuMg 40L (ground-based fire control radar ). After the competitor Telefunken won this tender with its " Würzburg " device, further development of the Lorenz device was initially stopped in 1939.

From 1941 onwards the device was converted for another tender by the Reich Aviation Ministry for use on board aircraft as a search radar against ships. Since no special antenna was required, three antennas were initially chosen as the simplest version, one for transmission, a second for reception from the left and a third for reception from the right. For rough route guidance, the receiving antenna had to be switched manually by the radio operator. A motorized antenna switch was installed later. The received signal was displayed optically on a cathode ray tube (type LB1) and so the observer or pilot could roughly see the position of the target as “left”, “right” or “straight ahead”. The greatest range was 150 km compared to convoys in the Atlantic. The device was installed in Fw 200 , Ju 88 and BV 138 reconnaissance aircraft. In order to prevent possible capture after a crash, there were several small explosive devices in the device that could be detonated by the pilot.

Further technical details in this air force service regulation: Primer FuG 200 for the radio warden and radio mechanic (PDF).

Submarine versions FuMO 61–65

"Hohentwiel U" was the adaptation of the FuG 200 for the Navy, especially on Type VII and IX submarines . A number of guard ships and outpost boats were also equipped with these devices in order to locate enemy aircraft, especially when throwing sea ​​mines , which considerably simplified the subsequent mine-clearing operation.

  • Range at 8 m antenna height: 8-10 km against sea targets and 15-20 km against air targets at an altitude of 200 m
  • 4 × 6 dipole not installed seaworthy, see picture below .

Technical specifications

property FuG 200 "Hohentwiel"
Transmission frequency 525-575 MHz (50 cm) self-excited
Pulse power 30-50 kW
Pulse repetition frequency 50 Hz
Pulse duration 2 μs
Swivel range left 30 °, middle, right 30 °
Beam width ?? °
antenna 2 × 4-element dipole group with reflector; Receiving antennas inclined to the side by 30 °
Range
  • 70 km against warships
  • 150 km against land
  • 10 km against submarines
Weight 22 kg
Power supply 24 V, 30 A, single armature converter
Tube assembly 2 × DS323 - later 2 × RD12Tf, 1 × LG7, 1 × LD1, 4 × LV1, 2 × LG1, 2 × LV1

gallery

  • Air force regulations with all technical details

  • US intelligence analysis of loot devices.

  • Submarine version FuMO 61 “Hohentwiel” antenna and FuMO Ant.3 “Bali” on board a Type XXI submarine

  • The same boat, view from further aft

See also

Individual evidence

  1. ↑ Wehrmachtsröhre LB1 in: Radiomuseum.org, accessed on October 29, 2015
  2. ↑ Kriegsmarine FuMO & FuMB equipped Vessels at gyges.dk, accessed on October 29, 2015
  3. ↑ Working group " Locating Devices ": Lecture from March 10, 1944 on cdvandt.org, accessed on October 29, 2015 (PDF; 1.3 MB)

Web links

literature

  • G. Müller: Development of radio measuring devices at C. Lorenz AG, 1935–1945 . Internal SEL archive booklet, 2nd expanded version, December 1981
  • RLM Werkschrift 4108, on-board radio measuring device FuG 200 . Top secret matter , August 1943
  • RLM regulation No. 75/790, test guide for on-board radio measuring device FuG 200 . October 1944
  • RLM aviation tubes ring binder, dates and guidelines on the use of aviation tubes . January 1945
  • K. Steimel: Report on the state of the tube technology in Germany at the end of the war . August 1945
  • U.S. Air Materiel Command Dayton OH, Summary Report No. F-SU-1109-ND, The High Frequency War - A survey of German Electronic War . 10th May 1946
  • CIOS Final Report 1746, German development of modulator valves for radar applications
  • CIOS report XXX-36, Physikalisch-Technische Reichsanstalt . June 1945
  • CIOS Report XXVII-46, Design of Radar Test Equipment at Siemens-Halske Munich
  • BIOS Report 1228, HF Instruments & Measuring Techniques
  • Achievement in Radio, Radio Science, Technology, Standards and Measurements at the National Bureau of Standards . US Department of Commerce, October 1986
  • Gerhard Megla: Decimeter wave technology . Fachbuchverlag Leipzig, 1952 (chapter measuring devices and measuring methods for decimeter waves)
  • Radio Measurements, Proceedings of the IEEE, Volume 55, June 1967. Hewlett-Packard , Microwave * Measurement Handbook, Chapter RF Peak Power Measurement, Procedures and Equipments
  • Boonton Electronics Company, Application Note AN-50, Measuring the Peak Power
  • US Naval Research Laboratory, ASB Radar Alignment Procedure . November 1942