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JO-4.06 →
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Infrared video transmitter - this page is a stub

JO-4.05 is a covert infrared light communications device, also known as photophone (German: Lichtsprechgerät), developed between 1986 and 1988 by VEB Carl Zeiss Jena in Jena (DDR) for the East-German security service MfS (Stasi). It is the wideband version of the JO-4.02 – also known as Große Dahme – and was suitable for the transmission of 5 MHz black and white video signals.

The device constains a wideband infrared FM transmitter with a bandwidth of 5 MHz, and a narrowband AM receiver with a bandwidth of 16 kHz. It was designed to work with a JO-4.06 at the opposite side, which has a wideband FM receiver and a narrowband AM transmitter.

We are currently unable to show a picture of the JO-4.05.

 More about the JO-4.06

This page currently acts as a placeholder for current and future information about the JO-4.05 optical transceiver. You can help us to expand this page by providing additional information.  Contact us

The diagram below shows the setup of a complete system, consisting of a wideband transmitter (JO-4.05) at the left, and a wideband receiver (JO-4.06) at the right. Note that only the JO-4.05 is suitable for the transmission of black and white video signals, using Frequency Modulation (FM).

  1. JO-4.05 and JO-4.06 design study (German) 1
    MfS, VVS GR 4/21 - 556/86/LVO. 1986.

  2. JO-4.05 and JO-4.06 design goal (German) 1
    MfS, VVS GR 4/21 - 132/88. Version 2. 1988.
  1. Document obtained from BStU [2] and kindly supplied by Detlev Vreisleben [1].

  1. Detlev Vreisleben, Personal correspondence
    November 2021.

  2. Bundesbeauftragte für die Stasi-Unterlagen (BStU) 1
    Federal Commissioner for the Stasi-Records.
  1. Full name: Bundesbeauftragte für die Unterlagen des Staatssicherheitsdienstes der ehemaligen Deutschen Demokratischen Republik (DDR) — Federal Commissioner for the Records of the State Security Service of the former German Democratic Republic (GDR) — officially abbreviated to BStU.

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© Crypto Museum. Created: Friday 10 December 2021. Last changed: Friday, 10 December 2021 - 21:02 CET.
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