Abstract: The invention relates to a method and an arrangement for reducing interference in a radio apparatus. The solution comprises a clock signal generator, an analog part and a controller arranged to measure interference arising from the harmonic frequencies of the clock signal on the given radio channel, and a controller for controlling the pulse width of the clock signal on the basis of the measurement.

Abstract: The invention relates to a method and an arrangement for producing an operating voltage of a desired form. A high-voltage operating voltage of a desired form is produced by means of a DC-AC converter. The desired operating voltage is usually a sine voltage. The DC-AC converter is controlled by means of a pulse form control signal of a signal generator, the pulse width of the control signal being controlled by means of a pulse width modulator. To change the pulse width of the control pulses, the operating voltage of a desired form produced by means of the DC-AC converter is compared with a reference signal and a comparator is used for forming a difference signal. The difference signal is used for controlling the pulse width of the control signal of the pulse generator in order to produce the operating voltage of a desired form.