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 catalogue    catalogue (German)      Fernkopierer HF1048 catalogue                     
  HF 146 und BS 109 1973 catalogue (German)      Fernkopierer HF1048 operating manual 1976  

Transmission sample   (HF 146  1970)


   Fax samples: Originals dated on the years 1970


Preparation for the repair work:

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.