In the radio data system (RDS), digital data which contain, among other things, a list of alternative frequencies (AF) with the same programme, from which the receiver can select a different receiving frequency when the receiving conditions deteriorate due to a change in location, are inaudibly transmitted together with the radio programme. However, the transmission of a complete AF list from the transmitter to the receiver can take up to 45 seconds and longer. To be able to switch without delay and inaudibly to alternative frequencies when the stored frequency of the master transmitter is not suitable for reception during a spontaneous programme call-up in different transmitting areas, the programme memories of the receiver should immediately provide a limited selection of suitable AFs. For this purpose, the memory content of this programme memory is empirically built up by automatically transferring alternative frequencies of the programmes radiated with the same PI code in the course of time from other memories and/or memory levels into the programme memories when the frequencies received during an operational or routine tuning of the receiver are confirmed as RDS transmitter frequencies having adequate quality of reception. IMAGE
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