Cables (1, 2) comprise first and second conductors (1, 2) for transporting signals to be picked-up in contactless manners. At first/second locations (3, 4), the first and second conductors (1, 2) are at first/second distances from each other. The first locations (3) are neutral locations where the conductors (1, 2) are parallel. The second locations (4) are pick-up locations. The second distances are larger than the first distances. Pick-up devices for picking-up signals in a contactless manner from the cables (1, 2) comprise parts for defining minimum values of the second distances. These parts may comprise core-parts, such as center ends (10) of E-shaped magnetic cores further comprising outer ends (11, 12) and backs (13). Methods for installing pick-up devices comprise steps of at second locations (4) increasing a distance between the first and second conductors (1, 2) from a value of the first distance to a value of the second distance. Twin-cables (1, 2) or twin-lead-cables (1, 2) are suited well for allowing signals to be picked-up in contactless manners.