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Wilhelm Quante StSG 52
Portable direction finder

The StSG-52 was a portable direction finding receiver built by Wilhelm Quante in Wuppertal (Germany) in 1952. It was used in the 1950s and 1960s to track down clandestine radio stations and foreign secret agents. It's full name is Störspannungs-Suchgerät (StSG) [1]. The receiver was based on the earlier Störsuch- und Meßgerät StG-50, that was developed by Quante in 1950 [6].
The StGS 52 is a single conversion super-heterodyne receiver with an intermetiate frequency (IF) of 470 kHz. It contains 5 valves (3 x DF91, DK92 and DAF91) and is powered by two battery sets: 6V for the heater and 72V anode voltage.

It was suitable for 3 frequency ranges:
  • LW: 150 kHz - 350 kHz
  • MW: 520 kHz - 1,4 MHz
  • GW: 1.02 MHz - 1.4 MHz

The receiver is housed in a wooden case, so that the internal 'window' coil can be used as a direction-finding antenna. When listening to a radio station, the operator has to rotate the receiver somewhat, in order to determine the direction of maximum (or minimum) field strength, using the S-meter at the bottom left. This procedure was repeated several times from different positions, until the location of the transmitter could be determined.

As the receiver is valve-based, it would consume more power from the batteries than a modern receiver would do. For this reason, the StSG-52 is operated by a trigger-switch that is hidden under the carrying grip. This design was used earlier on a wartime direction finder by Siemens. Due to its rather limited frequency range (150 kHz to 2.7 MHz), the StSG-52 was replaced later in 1952 by its successor the ASRV-52 that was suitable for frequencies up to 11 MHz.
The complete StSG52 unit The trigger-switch hidden under the handle The field-strength indicator The frequency dial (one lane for each band) PTT RCD internal inventory number The interior of the StSG52 Close-up of the adjustable parts Warranty card for the valves

The unit shown here has been in use with the Dutch Radio Monitoring Service, the RCD (Radio Controle Dienst), in The Hague (Netherlands) until the 1960s. A separate name shield with the internal inventory number of the RCD is present on the receiver, just below the leather grip. The unit shown here has internal serial number 12.

 More about the RCD
In Germany, the Quante StSG 52 was used for finding clandestine radio stations, but also for locating TV sets. In the early days of television, customers needed to pay a fee for a permit to receive television and radio broadcasts. If you did not pay for a reception permit, you risked a fine or, worse, imprisonment. As the local oscillator (LO) of a TV set emitted a signal that could be picked up with a sensitive receiver outside the house, the Deutsche Bundespost (German Post Office) used Quante direction finders to locate non-registered (and hence illegal) viewers.

Two men with a Quante StSG 52, locating TV receivers, probably in Berling, in 1956.

The image above shows two employees of the German Post Office in front of a Volkswagen van of the Funkmessdienst (Radio Monitoring Service) of the Deutsche Bundespost on a street, probably somewhere in Berlin, in September 1956. The man on the right carries a Quante StSG 52 on his shoulder, whilst holding a directional antenna in his hand. The other man holds a Telefunken Teleport 5 two-way radio in his hands and is probably communicating with another search team.
Two men with a Quante StSG 52, locating TV receivers, probably in Berling, in 1956. Close-up of the Quante direction finder

About Quante
Quante was once an idependant German manufacturer of telecommunications equipment, with its head office in Wuppertal (Germany). They should be seen as one of the pioneers of the telecommunications industry. At the height of their success (1999) they had an annual turnover of 700 Million DM (350 Million Euro) and a profit of 10.9 Million DM (5.4 Million Euro). In 2000, they had 2400 employees on the payrol.
The company was founded in 1892 by locksmith Wilhelm Quante and was initially based in Elberfeld (Germany), concentrating on the manufacture of heating devices. Af few years later the company started to take on repair jobs for telephone and telegraph lines of the German Post Office (Kaiserlichen Post). In 1910, the name was changed to Fabrik für Telegrafenbaumaterialen und Apparate and later to: Wilhelm Quante Spezialfabrik für Apparate der Fernmeldetechnik [2].
Quante AG
During World War II (between 1942 and 1944), Quante used female convicts from Russia and the Ukraine, but not much is known about this period. In 1967, the name of the company was changed to Quante Fernmeldemontagen GmbH (Quante Communications Manufacture Ltd). In 1988 the company was changed to a Publicly Listed Company (Plc), which and entered the stock market on 22 March 1991 as Quante AG.
In 2000, Quante AG was taken over by 3M and became a subsidary of 3M. After a restructuring in 2003, the company's premises in Wuppertal was given up and was moved to Neuss (Germany) [3]. The activities have since been integrated with 3M's and the name Quante gradually disappeared.
In 2005, after a management buy-out (MBO), Quante Fernmeldemontagen GmbH was established. The new company specialises in the field of cableing, networks and maintenance. In 2007, the company was renamed once again, and is now called QFM Fernmelde- und Elektromontagen GmbH [4]. With offices in Berlin, Hamburg-Norderstedt, Wuppertal and Sindelfingen (Germany), and over 200 employees, they are still in business today (2013).
Help required
The above information is all we have at the moment. We have not been able to find circuit diagrams and a suitable user manual for this device. Even the manufacturer, the former Quante, has not been able to help us any further, as details about this device are missing from their records [1]. If you have additional information, or additional accessories, please contact us.
  1. Personal correspondence between a previous owner and Quante AG in 1993
    30 November 1993. Crypto Museum #300719.

  2. Wikipedia, Quante (Unternehmen)
    History of Quante (German). Retrieved 12 October 2011.

  3. 3M, Information der Quante AG Umzug nach Neuss/Lieferabwicklung
    Information about Quante moving to Neuss (German). 12 September 2004.
    Site no longer active in January 2013

  4. QFM - Quante Fernmeldemontagen GmbH, Werdegang
    QFM Website. Retrieved 12 October 2011.

  5. Wilhelm Quante, Funkstörspannungs-Messgerät ASRV-52
    User Manual (German). Date unknown, but probably 1952.

  6. Wilhelm Quante, Störsuch- und Meßgerät St G 50
    User Manual and circuit diagram (German). 29 June 1950. 1
     Circuit diagram in high resolution

  1. StG-50 manual kindly supplied by Gabriele Garbuglia from Italy.
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