Lorenz beam

[1] The first experimental system had been installed in 1932 at Berlin-Tempelhof Central Airport and was demonstrated at the International Air Service Conference in January, 1933.

[1] The Lorenz company referred to it simply as the Ultrakurzwellen-Landefunkfeuer, German for "ultra-short-wave landing radio beacon", or LFF.

It was also adapted into versions with much narrower and longer-range beams that was used to guide the bombers on missions over Britain, under the name Knickebein and X-Gerät.

This led to a rotating version of the same system for air navigation known as Elektra, which allowed the determination of a "fix" through timing.

Further development produced a system that worked over very long distances, hundreds or thousands of kilometres, known as Sonne (or often, Elektra-Sonnen) that allowed aircraft and U-boats to take fixes far into the Atlantic.

The center antenna was always provided with the RF signal, while the other two were short-circuited by a mechanical rotary switch turned by a simple motor.

The keying of the contacts on the switch were set so that one antenna was shorted for 1/8 of the time, considered a "Dot" and the other 7/8 oth the time considered as a "Dash",[1] opposed to the duration of dit, dah and pauses as defined for the Morse code, were e.g. a dash is 3x the duration of a dot.

When he flew over the VEZⓘ, he would start descending on a standard glide slope, continuing to land or abort at the HEZⓘ, depending on whether or not he could see the runway.

Lorenz could fly a plane down a straight line with relatively high accuracy, enough so that the aircraft could then find the runway visually in all but the worst conditions.

However, it required fairly constant monitoring of the radio by the pilot, who would often also be tasked with talking to the local control tower.

Later derivatives of the system had signals of equal length in the pattern left-right-silence, to operate a visual indicator in the cabin.

'Sun') was a derivation of Lorenz used by the Luftwaffe for long-range navigation out over the Atlantic using transmitters in Occupied Europe, and another in neutral Spain, and after its existence had been discovered by the British, under the direction of R. V. Jones it was allowed to continue in use, un-jammed, because it was felt that it was actually more useful to RAF Coastal Command than it was to the Germans.