← Dahme 1
Opto-electronic voice transceiver
- wanted item
Dahme 2 1 was a transistorised portable
opto-electronic device for speech (voice) communication
through infrared light (German: Lichtsprechgerät),
developed in the early 1960s by the Operativ Technischer Sektor
of the repressive intelligence service of the former DDR (East-Germany) —
Ministerium für Staatssicherheit
(MfS), also known as the Stasi.
It was combined with a regular 35 mm photo camera that was used as a
rangefinder, and was suitable for Short Range Agent Communication (SRAC)
– over a distance of 2 km – with a Dahme 1 device
at the opposite side.
The device consists of an infrared optical system that is bolted to the
bottom of a regular 35 mm camera. It is shown in the image on the right,
mounted onto a common photographic tripod.
The device is connected to an external amplifier that is not visible
in the image. Once the device is aimed at the opposite station, the shutter
is opened and the lens is used for the receiver.
The infrared transmitter is housed in the lower part.
In 1964, West-German authorities confiscated a Dahme 2
from an East-German Stasi agent, who had used it to
contact a station in
East-Berlin, located in a
house across the Teltow channel.
At the first floor of the house,
behind the rightmost window, was a Dahme 1 station.
At the time, the East-West border ran through the middle of the Teltow channel.
It is believed both devices (Dahme 1 and Dahme 2) were inspired on
the American XE-2 device that had been confiscated
by the Stasi in 1959, when Western (CIA) agent Gisela Gebhardt
was arrested. As far as we know, the only surviving sample of a Dahme 2
is at the Bundeskriminalamt (BKA) —
the German Criminal Police in Köln (Germany), which is where some of
the photographs below were taken .
➤ More about Dahme 1
The Dahme is a river that flows in the German states of Brandenburg
and Berlin. The Stasi commonly used river names for its infra-red
(IR) communication devices. As Dahme is pronounced the same as the
German word Dame (lady), the name was easily transformed into Dame 2
TypeLine-of-sight (LOS) light-based communication device
PurposeCovert cross-border agent communication
PurposeSpeech, recorded audio
UsageIndoor (limited outdoor usage)
Angle (2ω)2° (TX), 0.5° (RX)
Bandwidth400-2000 Hz ±6dB
Range2 km (against Dahme 1)
800 m (against Dahme 2)
Power5 to 6V DC
DimensionsOn-camera unit: 110 x 90 x 38 mm
Amplifier: 120 x 90 x 17 mm
WeightOn-camera unit: 480 g
Amplifier: 150 g
Full name: Bundesbeauftragte für die Unterlagen des Staatssicherheitsdienstes
der ehemaligen Deutschen Demokratischen Republik
Federal Commissioner for the Records of the
State Security Service
of the former German Democratic Republic (GDR) —
officially abbreviated to BStU.
Document obtained from BStU  and kindly supplied
by Detlev Vreisleben .
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© Crypto Museum. Created: Thursday 09 December 2021. Last changed: Monday, 20 December 2021 - 09:56 CET.