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Schnatterinchen   2028
Baudot-to-speech converter - under construction

Schnatterinchen (cacklerina) 1 was an analogue speech generator, developed in 1964/1965 by the Institut für Kosmosforschung 2 (Space Research Institute) in the former DDR (East Germany) and built by the DDR Volkswirtschaft (VW) [2]. It was named after a popular TV character and was used for sending Central-to-Agent messages – commonly encrypted with a One-Time Pad – as endless strings of seemingly random numbers, read by a female voice, and broadcast by the so-called numbers stations. Also known as project 2028 and Telegrafie-NF-Analog-umsetzer S 1.3 3 [4].

The device replaced a small army of female speakers that had previously been reading the number-based messages live in a small studio, recording it on tape for broadcasting later on.

At the heart of the machine is the motor-driven drum shown in the image on the right. It has 13 discs, or wheels, that are mounted on a common axis. A piece of 12-14 cm ferro-magnetic audio tape is glued to the circumference of each wheel. At the top are 13 magnetic heads that pick up the audio from the revolving tapes, arranged as two rows with 6 and 7 heads respectively.
Drum with 13 discs

The discs can be seen as 13 individual audio tracks, each holding one number (0-9), the word Achtung (attention), Trennung (space) or Ende (end). Each magnetic head is wired individually at the rear side, allowing an amplifier with an electronic input selector, to pick the desired track.

The start of the tracks is marked by a tacho-sensor that is mounted at the right side. Its (red) wire is visible in the image above. The pulse from the tacho-sensor is also used to advance the punched paper tape holding the message by one position on each revolution of the drum.

The drum was mounted inside the 19" enclosure shown in the image on the right, together with a motor, the circuit boards and the power supply unit. At the front panel is a common 5-bit tape reader, for input of a punched paper tape which contain the message in ITA2 (baudot) standard.

Schatterinchen was developed during the course of 1964 and 1965, and was introduced during the second half of 1965. Some time later, a spanish variant was released. Mistakes in reading numbers were ruled out and live speakers were no longer required. It is currently unknown how many machines were built, but it is certain that very few have survived. At least three different design variants were made (2028, 2028.2 and 2028.3). A single 2028.3 unit was manufactured in 1976 for the price of DDM 15,000 4 [4]. The device shown here is not in working condition and consists of a selection of 2028.2 and 2028.3 parts that were supposed to have been scrapped [1].

Around 1980, the Schnatterinchen Baudot-to-Speech converter was succeeded by the fully digital Device 32620 in which the same female voice that was previously held on short pieces of ferro-magnetic tape, was stored in a set of EPROMs. It was supplied to various countries, including the USSR, and was used well into the 1990s. Like Schnatterinchen it was also available in Spanish.

  1. The translated name 'cacklerina' is the female diminutive of the English word 'cackler'.
  2. Part of the Akademie der Wissenschaften der DDR (East German Science Academy).
  3. In the original documentation, the device is called FS-NF-Umsetzer, which is short for Fernschreib-Niederfrequenz-Umsetzer (telegraphy-audio-converter, or telex-audio-converter).
  4. DDM was the currency in the former DDR, today known as the Ostmark (Eastern Mark).  Wikipedia
  5. Pittiplatsch and Schnatterinchen were popular puppet characters in the children's television show .  Wikipedia  German

Drum with 13 discs
Drum with 13 discs
Side view
Close-up of the 13 discs
Magnetic heads
Close-up of the magnetic heads
Magnetic head - close-up
Gaps in the discs
1 / 8
Drum with 13 discs
2 / 8
Drum with 13 discs
3 / 8
Side view
4 / 8
Close-up of the 13 discs
5 / 8
Magnetic heads
6 / 8
Close-up of the magnetic heads
7 / 8
Magnetic head - close-up
8 / 8
Gaps in the discs

Female voice
From 1961 onwards, the woman 1 shown in the image below, was one of the female speakers of the East German numbers stations. Like most of the speakers, she was living with her family on the compound of Funkobject 2 Kesselberg. Initially the numerical messages were read live in one of the small studios in the basement of the Kesselberg site, where they were recorded on tape.

The tapes were then played back at specific times via a strong short wave (SW) transmitter with an output power between 10 and 100 kW.

In 1964/1965, whilst she was was on leave to give birth to a child, she was asked to lend her voice to a new device named Schnatterinchen, which was then under development. In the small studio in the basement, each word had to be fitted onto a 12-14 cm piece of audio tape.

According to her own account [3], the words Achtung (Attention) and Sieben (Seven) were the most difficult to record. Furthermore, the words had to be pronounced in such a way that they could be discriminated unambiguously through a noisy narrowband short wave radio channel. The pre-recorded tape segments were later mounted onto the discs of the Schnatterinchen machine.

Some time later she was also asked to lend here voice to the Spanish version of the machine, which was subsequently recorded in the studio of the DDR broadcasting service 3 in Berlin. In the early 1980s, the same voice was digitized for use in the digital successor: Device 32620.

For the lady in the picture this marked the end of an era, but in the following years she frequently tuned in to the Stasi frequencies on the short wave radio bands, to verify that here voice was still being used. In January 2010, she wrote a letter in which she explained here role as the voice [4].

 Read the full letter

  1. The name of the female speaker is currently unknown.
  2. Literally translated 'Radio Object' - here used to identify a site.
  3. Rundfunkhaus der DDR, Nalepastraße, Berlin (East Germany).

Origin of the name
The device was named after a popular puppet character of a female duck in a DDR children's television show that was aired in the early 1960s by the Deutscher Fernsehfunk (DFF), the state television broadcaster of East Germany [5].

The television show was known as Meister Nadelöhr erzählt (Narrations from Master Needle Eye) and was part of the daily children's show Unser Sandmännchen (our sand men) that aired from 1955 to 1991. Famous characters of the show were Pittiplatsch and Snatterinchen, with the latter appearing for the first time in 1958 [6].
Successor   32620
In the early 1980s, Schnatterinchen was replaced by the fully digital Device 32620, in which the same voice was stored in an EPROM. Language variants were available in German and Spanish.

The device had a long life span was used well into the 1990s, not only in the DDR, but also in other Warsaw Pact countries and in Cuba.

 More information
Device 32620

Speech tracks
Track German Pronunciation Translation
1 Eins Eins One
2 Zwei Zwo Two
3 Drei Drei Three
4 Vier Vier Four
5 Funf Fun-nuf Five
6 Sechs Sechs Six
7 Sieben Sie-ben Seven
8 Acht Acht Eight
9 Neun Neu-en Nine
10 Nul Nul Zero
11 Achtung Achtung Attention (start)
12 Trennung Trennung Separation (space)
13 Ende Ende End
Schnatterinchen is known by various names, including:

  • Schnatterinchen
  • Projekt 2028
  • Telegrafie-NF-Analog-Umsetzer S 1.3
  • FS-NF-Umsetzer
  • Fernschreib-Niederfrequenz-Umsetzer (telex-audio-converter)
  • S 1.3
  • Stimme
  • Eiserne Frau (iron lady)
  • Kluge Frau (clever lady)
  • Schlaue Frau (smart lady)
  1. FS-NF-Umsetzer, Projekt 2028.4
    Technical description with circuit diagrams (German).
    MfS-Abt. 26, Nr. 2011. 1
  1. Document obtained from BStU, kindly supplied by Detlev Vreisleben.

  1. Anonymous, Original parts of Schnatterinchen device - THANKS !
    Crypto Museum, July 2017.

  2. Detlev Vreisleben, Personal correspondence
    July 2017.

  3. Anonymous, Letter from female East-German numbers speaker
    30 January 2010.

  4. MfS, OTS Abteilung 33, Jahrsabschlußanalyse 1976
    13 January 1977. 3 pages. 1

  5. Wikipedia, Deutscher Fernsehfunk
    Retrieved June 2018.

  6. Wikipedia, Pittiplatsch
    Retrieved June 2018.
  1. Document obtained from BStU, kindly supplied by Detlev Vreisleben.

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Crypto Museum. Created: Wednesday 19 July 2017. Last changed: Saturday, 02 June 2018 - 14:32 CET.
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