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Minifon Armband-Mikrofon - Wrist watch microphone ohne Schalter

Minifon Armband-Mikrofon - Wrist watch microphone ; Protona GmbH; (ID = 2592257) Microphone/PU Minifon Armband-Mikrofon - Wrist watch microphone ; Protona GmbH; (ID = 2592258) Microphone/PU
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Minifon Armband-Mikrofon - Wrist watch microphone ; Protona GmbH; (ID = 2592257) Microphone/PU
Protona GmbH;: Minifon Armband-Mikrofon - Wrist watch microphone [Microphone/PU] ID = 2592257 888x2000
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For model Minifon Armband-Mikrofon - Wrist watch microphone ohne Schalter, Protona GmbH; Hamburg:
My Microphone/watch for Minifon spy recorders
 
Country:  Germany
Manufacturer / Brand:  Protona GmbH; Hamburg
Year: 1955 ?? Category: Microphone or Pick-up element
Wave bands - without
Details
Power type and voltage No Power needed
Loudspeaker - For headphones or amp.
Power out
from Radiomuseum.org Model: Minifon Armband-Mikrofon - Wrist watch microphone [ohne Schalter] - Protona GmbH; Hamburg
Material Metal case
Shape Miscellaneous shapes - described under notes.
Dimensions (WHD) 50 x 50 x 13 mm / 2 x 2 x 0.5 inch
Notes

Protona Armband-Mikrofon zur Verwendung z.B. mit dem Minifon P55. Das Kristallmikrofon ist in ein Armbanduhr-Gehäuse eines Chronographen eingebaut, die Uhr selbst ist Attrappe und hat keine Funktion.

Ausführung ohne Schalter (Fernsteuerung des Minifons). Siehe auch Armbandmikrofon mit zusätzlicher Schaltfunktion.


Wristwatch microphone.
Microphone embedded in fake watch
Microphone with crystal transducer
There is no watch mechanism, the hands do not move.
Buttons not operational in the normal model.
There is a version in which the buttons act as a remote control for the M51 or M55 recorder.
Microphone output on internally connected and non-removable cable.
1 meter long cable to end in a 3.5 mm audio plug.
Typical DC impedance:  measured from 4 MΩ to 5 MΩ.
Maximum output signal of about 500 mV of amplitude when submitted to a loud voice.
Leather bracelet.

Application
Used in espionage operations as an input to the spy recorders manufactured by Minifon and Protona in the period from 1950 to 1965.
The cable was hidden under the sleeve of the shirt and carried the signal to the pocket recorder.

Net weight (2.2 lb = 1 kg) 0.050 kg / 0 lb 1.8 oz (0.11 lb)
Mentioned in - - Manufacturers Literature
Literature/Schematics (1) DBP - Patent Nr. 1875750, eingetragen 18.7.1963
Literature/Schematics (2) Der Spion in der Tasche; Roland Schellin; ISBN 3-936012-00-8

Model page created by Moisés Piedade. See "Data change" for further contributors.



All listed radios etc. from Protona GmbH; Hamburg
Here you find 32 models, 25 with images and 12 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.




  
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