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Gretacoder 104
Speech scrambler

The Gretacoder 104 was a voice scrambler for mobile applications, sold by Gretag in Regensdorf (Switzerland) in the early 1980s. Contrary to most other Gretag encryption products, the unit was not manufactured by Gretag, but by Telsy in Italy. It was sold by Gretag as an OEM product.

The Gretacoder 104 is housed in a ruggedized green metal case, making it suitable for use in harse environments, such as a military vehicle. As it uses voice scrambling, it is far less secure than the later true (digital) encryption units.

The unit is compatible with the Gretacoder 103 telephone scrambler and has two modes of encryption: time-domain scrambling and two-dimensional scrambling (a mixture of time-domain and frequency-domain scrambling). As it is normally connected to a radio transceiver, it is suitable for half-duplex connections only.

The Gretacoder 104 is identical to the Telsy TDS 2004M. For further information and additional photographs, please refer to our page about the Telsy TDS 2004M. The Gretacoder 104 is the military variant of the Gretacoder 103 telephone scrambler. Both voice scramblers were built by Telsy with whom Gretag had a very good relationship [3].

  1. Gretag, Gretacoder 104, Voice Scrambler
    4-page full-colour brochure. Date unknown, but probably early 1980s.

  2. Gretag, Gretacoder 104
    5-page product specification. Date unknown, but probably early 1980s.

  3. Oscar Steila, Managing Director of Telsy S.p.A.
    Personal correspondence, June 2013.
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Crypto Museum. Created: Friday 21 June 2013. Last changed: Saturday, 24 February 2018 - 06:53 CET.
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