METHOD FOR EXAMINING SIGNAL LEVEL-DEPENDENT PROPERTIES OF TRANSMISSION APPARATUSES ESPECIALLY OF SIGNAL LEVEL-DEPENDENT ATTENUATION DISTORSIONS OF CODEC'S FOR PCM CIRCUIS, AND DEVICE FOR THE APPLICATION OF SAID METHOD

摘要

1. A method of testing level-dependent characteristics of transmission devices, in particular the level-dependent attenuation distortion of codes for PCM-devices, characterised in that into the test item there is fed a test signal which comprises oscillations of closely adjacent, separable frequencies as signal components or which corresponds to oscillations in the range of which the level-dependent characteristics which are to be tested remain at least approximately constant and whose signal components possess different levels, that moreover the test response is transformed from the time domain into the frequency domain and the result is related to the test signal in the region thereof.