Abstract :
Consideration is given to the v.h.f. transmission of stereophonic programmes, restricted to f.m. transmitters with a sub-carrier system. Criteria are given, indicating the superiority of the so-called double f.m. system, which has a much smaller deviation than usual of the main carrier due to the sub-carrier, the deviation of which is reduced to only 15 kc/s. A circuit description is given of both the transmitter duplexer and the adaptor necessary for ordinary f.m. receivers. Special attention has been paid to applications of sub-carrier systems other than for stereophony. These lead to more stringent requirements for the crosstalk attenuation.
