1、CCIR VOLUME*X-L qo m 4w o504012 T m Rec. 461 t 35 RECOMMENDATION 467 TECHNICAL CHARACTERISTICS TO BE CHECKED FOR FREQUENCY-MODULATION STEREOPHONIC BROADCASTING Pilot-tone system (Question 46/10, Study Programme 46F/10) (1 970) The CCIR UNANIMOUSLY RECOMMENDS that during programme transmission instru
2、ments should indicate the percentage of peak-modulation in the 1. main carrier by the following: 1.1 the main channel, M; 1.2 1.3 the pilot signal; 1.4 the stereophonic sub-carrier, S ; all signals specified in Recommendation 450, simultaneously; 2. 2.1 2.2 2.3 2.4 2.5 sub-channel, S into the main c
3、hannel; 2.6 2.7 2.8 2.9 that in addition, the following characteristics should be measured during periods of test and adjustment: the frequency response of the M and individual A and B channels; harmonic distortion in the individual A and B channels; the signal-to-noise ratio in the individual A and
4、 B channels; the crosstalk attenuation between the A and B channels; the crosstalk from. the main channel, M, into the stereophonic sub-channel, S, and from the stereophonic the frequency of the pilot signal; the degree of suppression of the sub-carrier; the phase of the sub-carrier relative to the pilot signal; the total unintentional amplitude-modulation of the main carrier.