a single piece electrode comb or device includes two circuit boards having conductor paths and two separate rows of needle - like recording electrodes which are electrically connected to separate paths of the respective circuit board encapsulated in a single plastic resin body with the electrode rows extending to a recording edge formed in a rib along one edge of the body . to form the electrode comb , a device having two substantially similar rectangular cross - sectional shaped halves is assembled in one position to form a winding core on which a wire is wound with a plurality of turns , clamped and joined to the respective circuit boards which are mounted on faces of the two halves , subsequently the wires are separated along a parting plane and the two halves are disassembled with one being rotated 180 ° relative to its previous position so that the faces with the recesses are adjacent each other to form a casting mold into which a plastic resin is injected to encapsulate the wires which after hardening of the plastic are trimmed back at least along the recording age .