Rudolf Kühnhold
Rudolf Kühnhold (born August 27, 1903 in Schwallungen ; † 1992 ) was a German physicist .
Life
Kühnhold entered after his physics studies , which he received at the University of Göttingen with a doctorate to Dr. rer. nat. completed, at the Torpedoversuchsanstalt Eckernförde (TVA) in the service of the Reichsmarine . There he quickly rose to the position of senior naval construction officer and in 1928 took over the management of the intelligence test department (NVA) of the Reichsmarine in Kiel . In 1931 he registered a patent for the location of objects under water with sound waves (active sonar ). In addition, he worked intensively on a project to expand the classic echo sounder . The aim was not only to measure the vertical depth to the seabed, but also to measure horizontally, comparable to today's radar , in order to determine the distance to other watercraft.
In the summer of 1933, Kühnhold came up with the idea of using electromagnetic waves instead of the sonar principle of the echo sounder based on sound waves . To do this, he used electromagnetic waves with a wavelength of 13.5 cm.
On May 12, 1934 he succeeded in an attempt to measure a distance of 2100 m for the ship Grille . His experimental device worked at a wavelength of 13.5 cm with 0.3 watt output power with a Barkhausen short tube developed by Hans Erich Hollmann (now known as a traveling wave tube ) on a dipole antenna mounted in a parabolic mirror . In the course of the development he came into contact with the two engineers Hans-Karl von Willisen and Paul-Günther Erbslöh from the Berlin company Tonographie. These two succeeded on October 12, 1934 and November 2, 1934, on the test site in Pelzerhaken , in extending the measuring distance to 12 km. This accelerated the bureaucracy immensely, so that the further development was officially commissioned by the Navy.
On September 26, 1935, Kühnhold presented the High Command of the Navy with a radio measuring device based on the principle of transmitting electromagnetic waves and receiving the resulting echo waves. In the experiment, the artillery training ship Bremse served as a target and was successfully measured by a radio measuring device that had 40 watts at a wavelength of 48 cm . Based on the good results, it was decided to further develop the process.
Since the development was subject to the highest level of secrecy, it was decided to use the less captivating and descriptive term De-Te ( decimeter telegraphy ) for the term "radio measurement" or for research work on sea and air reconnaissance with electromagnetic waves .
Kühnhold is therefore one of the co-inventors of the radar device.
See also: German technical device , Freya
Web links
- Literature by and about Rudolf Kühnhold in the catalog of the German National Library
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- ↑ Development of radio research in the German Navy by AOBauer, Diemen, NL, December 27, 2004 (PDF; 476 kB) (Engl.)
| personal data | |
|---|---|
| SURNAME | Kühnhold, Rudolf |
| BRIEF DESCRIPTION | German physicist |
| DATE OF BIRTH | August 27, 1903 |
| PLACE OF BIRTH | Schwallungen near Meiningen , Thuringia |
| DATE OF DEATH | 1992 |