A radio module that detachably connects with a host device. The device is located at a first site, and the unique identifier is sent from the device to a second site. The control module is provided for generating control signals for the satellite receiver, so that satellite image signals can be received when selecting certain channels that would otherwise be available for VHF and UHF reception. The processor controls gating of the bursts of pulsed sound and the duration of the reception of echoes by the array.