Process and apparatus for changing frequency in a multichannel radio system

When changing the frequency in multi-channel radio systems, voltage-controlled oscillators (3) are stabilized by phase-locked loops (2). The radio frequency (RF) is digitally divided down and compared to a fixed, stable reference frequency (FR) equal to the channel spacing. This results in long channel settling times at small channel spacings, which lead to high power consumption. A reference frequency (FR) varied over several channels achieves higher reference frequencies (FR) and thus lower control settling times and lower power consumption. In addition, a temperature compensation and a compensation of circuit tolerances is achieved. Autonomous transmitting and receiving devices in alarm sensors of radio alarm systems