A medical probe, including a flexible insertion tube having a distal end for insertion into a body cavity and including one or more sensors mounted in the distal end, and a handle coupled to a proximal end of the insertion tube. The medical probe also includes a cable having a proximal end and a distal end, which is coupled to the handle so as to receive signals conveyed through the insertion tube from the one or more sensors, and a base unit coupled to the proximal end of the cable. The base unit contains a power source, and a probe wireless transceiver coupled to receive the signals from the cable and to communicate over a wireless connection with a control console.