The Telefunken Kompass Sender was one of the earliest

radio navigation Radio navigation or radionavigation is the application of radio waves to geolocalization, determine a position of an object on the Earth, either the vessel or an obstruction. Like radiolocation, it is a type of Radiodetermination-satellite servi ...

systems to be deployed. It was developed in 1907 ^p.141by the German electronics firm Telefunken. It was used primarily for long-distance navigation by

Zeppelin A Zeppelin is a type of rigid airship named after the German inventor Ferdinand von Zeppelin () who pioneered rigid airship development at the beginning of the 20th century. Zeppelin's notions were first formulated in 1874Eckener 1938, pp. 155� ...

s, and was taken out of service around 1918. -Telefunken-Kompass 2024b28 rev

The system consisted of a series of 32 individual 60 m long cables supported in the center by a single mast and reaching the ground at their ends, forming a sort of umbrella-shaped device. Pairs of cables were wired to each other to form a series of sixteen 120 m long dipole antennas, now known as inverted-V antennas. The transmitter was first connected to all sixteen antennas and sent the

morse code Morse code is a telecommunications method which Character encoding, encodes Written language, text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code i ...

identifier for the station. After the identifier was sent and a specific time interval had passed, the system started switching on individual dipoles in order around the station. An aircraft located at some distance from the station would first listen for the identifier, and then when the time delay expired, start a stopwatch. Since the pattern broadcast from the dipoles was highly directional, they would hear the signal grow in strength as the powered antennas "approached" them, the strongest signal being when the powered set was at right angles. It was later discovered that the minimum point was much easier to distinguish, with the signal dropping almost to zero when they were aligned directly off the end of the powered dipole. Like many radio navigation schemes, the Kompass Sender produced identical patterns along the selected path, as well as the 180 degree reciprocal course. This ambiguity had to be eliminated by taking a second measurement using some other navigation system. For this purpose, two Kompass Sender stations were built, at Kleve near the Dutch border, and at the German Zeppelin base at Tønder in today's Denmark. Together the stations offered service over the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

and

English Channel The English Channel, also known as the Channel, is an arm of the Atlantic Ocean that separates Southern England from northern France. It links to the southern part of the North Sea by the Strait of Dover at its northeastern end. It is the busi ...

areas.

References

* Annis Salsbury, "Safeguarding Vessels by Radio", ''Popular Science'', January-June 1916, pp. 451-453 * Arthur Bauer
"Some historical and technical aspects of radio navigation, in Germany, over the period 1907 to 1945"
26 December 2004 * "How the Zeppelin Raiders Are Guided by Radio Signals", ''Popular Science'', April 1918, pp. 62-634 {{refend Radio navigation

See also

References