A lock includes a cable configured as an antenna, a shackle pin connected to one end of the cable, and a lock body connected to another end of the cable. The lock body includes a channel for the shackle pin, at least one lock member adjacent the channel pivotable from an open position disengaged from the shackle pin to a closed position engaging the shackle pin, a retainer associated with a lock member driven from a released position disengaged from the lock member to an engaged position retaining the lock member in the closed position, and an electrically driven linear actuator driving the retainer to the released position in response to a signal received by a receiver via the antenna.