Blaupunkt-werke Gmbh

Robert Boschgmbh

Helmut Liman

Jurgen Kasser

Wilhelm Hegeler

Harald Bochmann

Matthias Scholz

Joachim Attig

Werner Henze

Wiedhold Warnecke

Peter Erben

The Radio Data System (RDS) protocol promulgated by the European Broadcasting Union provides for alternate frequencies (AF) for the same broadcast. Receivers periodically switch over to such an alternate frequency, leading to momentary crackling noises. In a radio receiver having a device for temporary switchover from a received frequency to some other frequency, substitute signals are inserted into the audio signals that are interrupted during the temporary switchover. The substitute signals are formed from the audio signals before and optionally also after the temporary switchover.

Radio receiver with masking of switchover noise

A program type PTY mode is integrated into an RDS radio receiver with a limited access surface by means of a mode switch in that the function of the station keys is changed to that of program type keys and that by way of a multiple actuation of the keys it is possible to call up sequentially different program chains having the same type of program at that moment.

RDS radio receiver with program type mode

A combination broadcast receiver and mobile telephone for motor vehicles is disclosed, in which acoustically operating devices are always switched off in the motor vehicle when a voice command detection circuit is switched on.

Combination broadcast receiver and mobile telephone

To simulate presence of a traffic information signal in a traffic information receiver which is muted upon reproduction of tape cassette programs or operated at a predetermined level, a momentary-operating control button is connected to a timing circuit to establish a timing interval which, when exceeded, provides a signal to a traffic information transfer switch to transfer the signals received from the receiver through the traffic information channel to permit setting of the volume level under traffic information conditions as desired and to demonstrate the operability under such conditions; upon release of the button, the system reverts to reproduction of tape or traffic information signals received by the receiver. Traffic information can thus be simulated even though no traffic information is being radiated by the transmitter to which the receiver is tuned.

Traffic information radio signal receiver

After a preliminary differentiation, the demodulated signal is supplied in parallel to a peak rectifier and to a second differentiating network, the outputs of the latter two circuits being added in the input circuit of a switching transistor that controls the blanking gate of a receiver. The value of the resistor across the output capacitor of the peak rectifier, as well as the rectifier capacitor, is so chosen in value that periodically recurrent pulses that may be persistently present in the signal build up a blocking bias on the switching transistor reducing its sensitivity and preventing corresponding differentiated pulses from switching it on, whereas occasionally or irregularly appearing pulses develop a negligible bias through the rectifier, so that their twice differentiated derived pulses will switch on the transistor and produce blanking.

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Nordstemmen, Germany

Helmut Liman