Part of the conductive loop of the threads is formed by a printed circuit on the substrate (5), where the group of the conductive strips (2) placed side by side is produced, and the core (1) is placed on them. The conductive strips (2) overhang from the groundplan of the core (1) and the ends of the conductive strips (2) overhanging on both sides of the core (1) form the connecting surfaces (4). The wires (3) shaped for the encirclement of the core (1) are connected to the connecting surfaces (4), whereby the wire (3) connects a connecting surface (4) of one conductive strip (2) with the connecting surface (4) on the opposite end of the neighboring conductive strip (2). After bonding to one end of the conductive strip (2) the wire is shaped above the substrate (5) by bending in such a way that it arches over the space intended for the core (1) and all wires (3) are shaped in such a way that they produce a channel for the core (1) placed on the substrate (5). The conductive strips (2) are sloped from the normal of the core (1) under an angle pursuant to the pitch of the thread and the wires (3) are led in the opposite slope under the same angle.