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Description |
English: A homemade "crystal" radio receiver, made in Greece, 1935. This example uses a razor blade and battery carbon to make a crude point-contact diode, instead of the galena cat's whisker detector used in most crystal radios. Receivers using this technique that were constructed by soldiers during World War 2 were also known as "foxhole radios". The battery included in this radio does not provide power to amplify the signal as in modern radios, but is used to apply a small bias voltage to the razor blade detector, to make it more sensitive.
Français : Un récepteur radio a cristal fait maison, se servant d'une lame de rasoir comme détecteur. Fabriqué en Grèce. Des récepteurs employant cette technique ont été construits pendant la guerre ont été également connus en tant que "foxhole radio".
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Date | February 2009 | ||||||||
Source | Own work (Own photo) | ||||||||
Author | Badseed | ||||||||
Permission (Reusing this file) |
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GNU Free Documentation License
EXIF data: | |
File name | homemade_radio_receiver_with_razorblade.jpg |
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Size, Mbytes | 1.1833896484375 |
Mime type | image/jpeg |
Camera manufacturer | NIKON CORPORATION |
Camera model | NIKON D40 |
Orientation of image | 1 |
Image resolution in width direction | 72 |
Image resolution in height direction | 72 |
Unit of X and Y resolution | 2 |
Exposure time | 10/300 sec (0.033333333333333) |
F number | f / 4.2 |
Exposure program | 4 |
ISO speed rating | 1600 |
Compressed bits per pixel | 4 |
Exif version | 0221 |
Lens focal length | 30 mm |
Date and time original image was generated | 2009:02:07 16:02:01 |
Date and time image was made digital data | 2009:02:07 16:02:01 |
Meaning of each component | |
Exposure bias | 0 |
Maximum lens aperture | 4.1 |
Metering mode | 5 |
User comments | ASCII |
Supported Flashpix version | 0100 |
Color space information | 1 |
InteroperabilityOffset | 3540 |
Sensing method | 2 |
Scene type | |
CFA pattern |