Track thinning at an IN point of consecutive recording is prevented by doing a head-track one-edge coincidence tracking by using a head of a larger width than the track width. According to the method, the cable clamp is checked by comparing the area necessary for clamping the cables with the inner-diameter area of the cable clamp; the control points related to the cable clamp are designated; and the data of the designated control points are added to the data of control points assigned to each cable in advance. After the data has been successfully removed in the time domain, the data is then transmitted in the frequency domain in which no data is transmitted at the frequencies where the data was precisely excised. The extremities of the magnetic pole members oppose the row of permanent magnets via an air gap. The output power is converted into a feedback signal by the isolation element. The cable can be pulled through a tunnel and through a piston of a ram.