morse decoder with DDLL (1)

The February 1976 issue of Elektor contained a design for a decoder that wou Id convert morse signals into alphanumeric characters. The disadvantage of this system was that the decoder had to be manually synchronised to the sending speed, which meant that it had to be individually adjusted for each incoming message and could not adapt to variable sending speeds. The new design is equipped with DOLL (Dot- Dash-Length-Logic), which automatically synchronises the decoder to the sending speed. The decoded morse signal is presented in a binary code that may be further processed digitally to drive a teleprinter, visual display terminal or other display. A simple display using · seven segment LED displays and utilising the `seven segment alphabet` described in Elektor July/August 1975 will also be described.