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Protona Minifon
Monske & Co GmbH

Protona was a German manufacturer of Minifon miniature wire and tape recorders. The company initially started as Monske & Co GmbH but after financial troubles the activities were taken over in 1952 by the newly founded Protona GmbH. Over the years, the company changed hands a number of times, as a result of which Minifon products were sold under different brand names, including Protona, Telefunken, EMI, and ITT. Minifon recorders were sold from 1951 to 1967.

Minifon recorders on this website
Minifon Mi-51, the first wire recorder from Protona
Minifon P 55, the successor to the Mi-51
Minifon Ataché, the first all-transistor tape-based Minifon
Minifon Special, a wire recorder for the secret services.
The world is in shock, when in 1951 the first miniature wire recorder, the Mi-51 is introduced on the Industriemesse (Industry Fair) in Hannover (Germany) [1]. For days on end, newspapers and magazines reported about this unbelievable marvel of modern engineering. At that moment, the Mi-51 is the worlds smallest recording device. It runs on batteries and has the ability to record over 2 hours of sound on a thin metal wire. It would soon become a popular device in the USA.

Covert recording
The recorder was initially intended for inconspicious recording of conversations. German electro-mechanical engineer Willi Draheim started its development in 1948. Shortly afterwards, he met Nikolaus Monske, a Hannover business man, who had the desire to covertly record business conversations. Monske had increasingly become irritated by the fact that in negotiations, despite a verbal agreement, his words were continuously twisted afterwards. Draheim suggested that his invention could be the solution to that problem, and together they set out to start a business.

With private money from Monske and help from his former World War II Luftwaffe colleague Ernst Genning, Draheim established a workshop with a laboratory in Faßberg. After aprrox. two years, the first recorder was ready for production, and patents were registered in twenty countries.

The initial forecasts were good. To allow series production of the recorders, Monske searched for help from his brother and for investors. With their finacial backup – and without any help from the regular banks – he established the company Monske & Co on 14 September 1951.
The Mi-51 in its protective green carrying case

One of the first customers, an American company, ordered 120,000 machines and was prepared to pay US$ 50,000 up front. By the end of 1951, Monske & Co had about 70 highly skilled employees on the payroll and a few months later, this number had increased to 180. Because of the world-wide growing interest in dictating machines, they began to target the machines at the business market as well. At the 1952 Industry Fair they could be found in the hall with Business Machines, rather than in the hall with Electrical Machines.

Financial problems
In 1952, the company got into financial trouble because of technical problems and supply problems in the USA. Many employees were sacked and even a financial injection of DM 500,000 by competitor Intona GmbH could nott turn the tide. After negotiations with BRAUN and other potential buyers had failed, the company was left no other choice than to go into receivership.

At that point, German electronics giant Telefunken became interested. The minifon would fit-in perfectly with their existing product range. It could be combined with Telefunken Microphones and the recently aqcuired AEG Recorder Division. They missed the opportunity however, as the newly founded company Protona GmbH took over the Minifon activities. Protona was founded by Liechtenstein business man Reinhold Stach, together with some financial partners. Stach is also one of the shareholders of competitor Intona. His unorthodox and firm control over the company would leave its impressions on the company and its employees in the following years.

Nearly all fired employees are brought back on the payroll, and between 1952 and 1955 several 10,000s Mi-51 units are produced. Although this may seem like a high volume, it isn't nearly enough to fulfil all orders. The production capacity never reaches its full potential. The majority of machines that come off the production line, are sold to the USA and the United Kingdom.

In April 1955, the Mi-51 was succeeded by the P-55. Presented to a selected audience just a day before the opening of the 1955 Hannover Messe (Hannover Fair) it was received well, despite the fact that it was still wire-based, whilst the industry was rapidly moving towards magnetic tape.

The reason for this is simple. The P-55 could record for more than 2.5 hours on a single wire and battery (later models even 5 hours). Not a single tape device on the market could do that.

In the following years, the P-55 became the new mainstream product, whilst newer models were introduced as well. In 1958, the company narrowly escaped another backruptcy when one of its shareholders got involved in a schandal.

The Minifon was especially popular in the English speaking world. In the UK it was sold by EMI.
The P-55 with the lid open

In the US, Protona was initially represented by GEISS, but from 1961 onwards, the P-55 was sold exclusively under the ITT brand, for a price of US$ 330.50.

Minifon Liliput
In 1958, Protona moved away from the use of minature valves, with the development of their first all-transistor recorder: the Minifon Liliput. It measured just 13.6 x 8.7 x 4.3 cm and was the smallest recording device in the world at that moment. Like its predecessors, it was wire-based.

The Minifon Liliput was a beautiful machine, but their were serious problems. The capacity of the battery – especially designed for this unit – was not powerful enough to last the full advertised recording time of 4 hours. As a result, only a small quantity was ever built. Today, Minifon Liliputs are extremely rare, as only a hand full of them have survived. A good description of the Lilliput can be found in Ronald Schellin's excellent book Spion in der Tasche [1].

Magnetic tape
Although Protona believed in the strength of wire-based recording, they also recognised the need for tape-based systems. After a few years of development they finally succeeded and in 1959 the Minifon Ataché was introduced. It was one of the first recorders to use a tape cartridge (cassette).

This was 4 years before the introduction of the popular Philips Compact Cassette, the standard that would reign for the next several decades [2].

Protona's tape cartridge could be installed in seconds, and became the basis for a wide range of tape-based devices, such as the Minifon HiFi (for music recording), the Minifon Office (a desk­top dictating machine) and the Minifon Studio.

 More about the Minifon Attaché

The Minifon Attaché with a tape cartridge (cassette)

Back to wire
In 1961, at the height of the Cold War and two years after the introduction of the Minifon Attaché, Protona took a step back with the introduction of yet another wire-based recorder: the Minifon Special. It was developed especially for the espionage business and allowed long recordings.

Despite the fact that the industry had meanwhile adopted magnetic tape as the way forward, and all Minifon devices that had been introduced since 1959 were tape-based, Protona kept believing in wire as the best recording medium.

It came in two models: S (standard) and L (long-play). The L-version allows recoring of 5 hours without replacing the battery or the wire spool, whilst the S-version is limited to 'just' 2.5 hours. Still very impressive. The size of the Minifon Special is just 10 x 17 x 4 cm, making it the ideal solution for body-worn covert recordings.
Controlling the Minifon Special whilst inside the leather case

Including the rechargeable battery and wire spools, it weighted no more than 800 g. Despite the high price of DM 985, it became a popular recorder with various law enforcement and intelligence agecies, but it would nevertheless be one of the last wire-based recorders to be mass produced.

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Early in 1962, Protona ran into trouble again. Due to a variety of technical problems with the Minifon Office, the inability to deliver machines in time and the ever increasing stocks, Protona is rapidly losing money. On top of that, Protona loses its 'motor' when owner Reinhold Stach dies after a brief but serious illness in February 1962.

In August 1962, the company is eventually bought by Telefunken. Production of all Minifon models - including the wire recorders - continues, with the exception of the Minifon Office.

Although the Minifon Office is cancelled by Telefunken, it is reborn in 1963 when a completely redesigned Minifon Office is introduced. It is sold under the Telefunken brand and looks different from the rest of the Minifon series.

Even under Telefunken control, the tide could not be turned. Each year there were fewer orders whilst the stocks, and hence the costs, increased, until the point were all interest in Minifon and its technology seems to have been lost completely. Finally, in 1967, the curtain falls for Protona GmbH and its once so popular Minifon.

Between 1967 and 1978, Minifon repairs are handled by the newly established company Fechner-Schulte. After that, until 1985, Minifon units are repaired by former Protona employee Herbert Scheibner. Since then, Minifon recorders have become highly wanted collectors items.

One of the most important reasons for the downfall of the Minifon is probably the introduction of the Compact Cassette by Philips in 1963. It revolutionised the market for portable recording devices and became the world-wide standard for tape cartridges in the following decades.

The inventor
Minifon inventor, Willi Draheim did not take part in any of this. He had already left the company in 1952, after he had sold his invention to Nikolaus Monske for DM 5000. He went to work for Engineering Company Bölkow in Stuttgard (Germany) where he designed the first all-transistor tape recorder the Tel-Tape. Over 50,000 Tel-Tape units were sold for the extremely low price of DM 89.50 (against DM 680 for the Minifon Mi-51). It was based on Draheim's latest invention: the Butterfly Patent. In later years, many hundreds of thousands of Japanese tape recorders would be based on this drive mechanism.

Index of Minifon recorders
Minifon accessories
  • Protona Watch/Microphone
  • Minifon Holster
  • Minifon Tape Cartridges
  • Table Speaker
Other Minifon products
  • Minifon KW - Transmitter and Receiver
  • Minifon REX - Pocket Radio
  • Combi Minifon RC
Brand names
  1. Roland Schellin, Spion in der Tasche
    Detailed history of Protona and the Minifon recorders
    ISBN 3-936012-00-8 (German)

  2. Roland Schellin, Spion in der Tasche  
    Completely revised edition (2022).
    ISBN 978-3982234007. Release date: 1 April 2022.  Amazon
  1. Roland Schellin, Spion in der Tasche
    Detailed history of Protona and the Minifon recorders
    ISBN: 3-936012-00-8 (German)

  2. Wikipedia, Cassette tape
    Visited 19 October 2021.
Further information
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© Crypto Museum. Created: Saturday 24 March 2012. Last changed: Monday, 28 March 2022 - 09:31 CET.
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