Abstract: The present invention relates to a device for selecting a specially marked radio signal among a number of radio signals. The device includes receiving equipment for the radio signals, which is arranged to automatically scan the frequency band within which the radio signals appear. The scanning is made by a sweep generator, which is part of the receiving equipment. A special locking circuit for the sweep generator (time base circuit) is activated when a radio signal is found during the scanning period, and the locking circuit, when activated, affects the sweep generator so that the scanning is stopped at least for a predetermined short period, suitably controlled by the locking circuit. The radio signal referred to is sensed during the mentioned short period after which the sweep generator is initiated to continue its interrupted scanning, provided the sensed radio signal does not have the mentioned marking.