Reproduced waveform with thin film magnetic heads, distortions (wiggles) of reproduced waveform are sometimes observed. In this study, a method for extracting wiggles from reproduced waveform was devised, and wiggle behavior was studied. Extracted wiggles were in pulse width from 40 to 80 ns, in amplitude from 10 to 30μV, and their locations during reproduced waveform were shifted by and external magnetic field, but wiggle width and amplitude were not affected. After write operation, wiggle pulse width and amplitude changed; however, the area under the extracted pulse was verified constant. Peakshifts of reproduced waveform increased when wiggles came close to the peak of the reproduced waveform, and wiggle amplitude increased.
