Hellfax - Transceiver HF 146  
Facsimile devices transmit documents with only black and white pixels, i.e. Texts and drawings.
When operating as a transmitter, the document to be sent is mounted on a drum,
the scanning unit, attached to the optics carriage, is beeing pulled by a flat belt
along the rotating drum. The scanning light is directed on the drum from above,
and the reflected light is converted into electrical signals by means of a photo cell.
The signals representing the black and white pixels are then sent over the transmission line.
Klein Fax KF 108 Datenuebertragung
When operating as a receiver, the received electrical signals actuate a tiny inked
recording wheel by electromagnetic force, which writes the black pixels on a sheet
of normal paper mounted on the drum.
  HF 146 1970       オーダー・ブック (ドイツ語)           
  HF 146 と BS 109 1973  オーダー・ブック (ドイツ語)  
  伝送サンプル  HF 146      
Various fax machines were inspected for functionality. Especially those components
made of plastic have suffered a lot after 50 years. These have become brittle or have
turned into a tough mass. The pictures in the following picture gallery were taken
during the examination on various fax machines.