A thrust needle bearing with an isolating layer has a cage with rollers, washers on which the rollers run, at least one of the washers is attached to the cage, backup surfaces fixed external to each of the washers and an isolating layer attached to at least one of the washers, which is interposed between the at least one of the washers and at least one of the backup surfaces of the bearing. Each AC bar includes a series of serially connected turns formed by litz wire having a plurality of strands, and at least one cooling tube. Transmission power control can be responsive to adjacent channel measurements.