Pungs throttle

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Pungs throttle

The Pungs choke is a transducer - throttle high frequency to control alternating currents. It was developed by Leo Pungs in 1913 while working for C. Lorenz . With it it was possible for the first time to modulate high-performance radio transmitters with speech and music in a satisfactory quality. It was in the early longwave - stations of the 1920s to the amplitude modulation used, but was also the damping and stabilization of compounds of wireless telegraphy in use.

With the first electric arc transmitters , one or more microphones were first connected directly to the antenna circuit to modulate a transmission signal with voice vibrations. However, with the increasing current intensities as the transmission power increased, the grains of the charcoal semolina microphones used at the time burned and stuck together at the contact points. The microphone had to be located directly on the transmitter and the speaker was in constant danger of burning his mouth or nose on the devices through which the antenna current flows. Leo Pungs developed a solution to these problems at C. Lorenz in Berlin, a parent company of what later became Standard Elektrik Lorenz AG . He switched an iron core to the antenna. The inductance and thus the loss resistance of the iron core changed depending on its premagnetization. The magnetization could then be controlled by a voice signal. This enabled speech or music to be modulated onto a radio signal.

The component, initially referred to as the "telephony throttle", but soon known as the pung throttle, was used both for the first radio test broadcasts by the company's own test radio station in Eberswalde and at the Königs Wusterhausen transmitter on Funkerberg, and enabled the first transmitters to be used from October In 1923 entertainment broadcasting began in Germany .

Since 1902 it was already known through the work of Reginald Fessenden that the apparent alternating resistance of a coil with an iron core changes when this iron core is magnetized by direct current. The idea was also introduced in 1913 by Ludwig Kühn at the Dr. EF Huth picked up again. However, the expansion to the tax procedure for radio telegraphy and telephony only succeeded through the work of Leo Pungs and Felix Gerth. Gerth was employed in the C. Lorenz transmission laboratory from 1914 and in 1927 took over the management as the successor to Leo Pungs. After its use in arc transmitters, the choke is said to have proven useful for use in machine transmitters and even for tube transmitters with significantly shorter wavelengths of up to a few hundred meters.

literature

  • Procedure for telephony and sound transmission by means of electric waves , Imperial Patent Office, Patent No. 281440, July 15, 1913
  • Leo Pungs: The control of high frequency currents through iron chokes with superimposed magnetization . In: Elektrotechnische Zeitschrift 44 (1923) issue 4, p. 21 ff.

Individual evidence

  1. ↑ a b First broadcast on December 22nd, 1920 . In: hifimuseum.de , accessed on March 19, 2016
  2. ↑ Otto Zinke , Heinrich Brunswig: High frequency technology 2: Electronics and signal processing , Springer-Verlag 1999, p. 539 f.
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  3. ^ A b Peter Lertes: The telephony transmitter . In Bibliothek des Radio-Amateurs Volume 14, edited by Eugen Nesper, Berlin 1926, p. 157
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