The multifrequency receiving unit RM-105 serves as a replacement part or as an extension for the PA system W.A.M.S.-05. The receiving unit operates in the UHF range of 863.100 - 864.900 MHz. The frequency range is divided into 16 channels, which can be selected as desired. The hand-held microphone HM-105, the transmitter module ALT-105 and the pocket transmitter TM-105 can be used for a wireless signal transmission to the receiving unit as they are tuned to the same frequencies.