Abstract: In a tuning circuit for a receiver which is continuously tunable over a number of wave ranges by means of a setting circuit, the receiver having an automatic wave range change-over, the tuning voltage is obtained from a subtracting circuit in which a changeable constant voltage is subtracted from a setting voltage which was obtained by means of the setting circuit, this changeable constant voltage depending on the wave range for adaptation of the wave range limits to the wave range.

Abstract: A circuit network for the non-linear digital-to-analog conversion of a periodic pulse signal having a linear average value which depends on a digital value into a direct current signal, wherein said network has different charge and discharge time constants for the pulse signals and the smoothing filter, so that a non-linear relation is obtained between the value of the input signal and the amplitude of the output signal of the filter circuit. The input network includes in series a resistor and a capacitor, the resistor of which is shunted at least partially by a diode.

Abstract: For simultaneous correction of all function adjustments of, for example, a television receiver, adjustable correcting information is stored by means of a normal function control members in a memory which is read out on operation of a function correction member.