In this paper we deal with some of the main blocks which consist a ste
reophonic RDS modulation system. As such we consider the 19 KHz pilot
tone of the FM stereo, the 38 KHz subcarrier modulated by the differen
ce of the two stereo channels and the 57 KKz subcarrier of the RDS dig
ital signal. Also, a digital substitute of the biphase signal generato
r required for coding and shaping of the RDS data preceding the balanc
ed modulator, is considered. The substitution of the balanced modulato
r by a multiplying DAC is another consideration. The synthesis of the
three carriers takes place by a multiplexed (triple) Direct Digital Sy
nthesizer (DDS). The multiplexed synthesizer can be considered indepen
dently for the generation of multiple frequencies.