Abstract: A data line comprising a stationary disk (34) and an opposed rotating disk (36) couples data from a stationary data source (30) to a rotating data module (12) to which the rotating disk (36) is fixed. The rotating disk (36) includes an insulating substrate (38) on which concentric arcuate strips (40) are formed in registration with corresponding strips on the stationary disk (36). The link transmits data from one disc (34) to the other (36) by capacitive coupling between corresponding strips to the two discs. The several pairs of corresponding strips are in separate parallel data channels, and crosstalk between the channels is prevented by intermediate ground strips (42) disposed between the data-carrying strips (40).