Telegraph distortion and distortion measuring

The definition of distortion with the resulting conclusions is of fundamental importance in determining the reliability of telegraph transmission circuits, judging the quality of the component sections, assessing maintenance requirements, and planning teleprinter networks. Being aware of this importance, the CCIT (International Telegraph Consultative Committee, since 1957 CCITT, International Telegraph and Telephone Consultative Committee) has been carefully studying the related problems for more than 30 years. Terms have been defined, values established, and detailed investigations carried out. The subsequent elucidations are based on CCIT publications.1¿3