Influence of Wiggle on Reproduced Waveform

In the reproduced waveforms from thin film magnetic heads, distortions ("wiggles") are occasionally observed. In this study, a method for extracting wiggles from the reproduced waveform was devised, and the characteristics of wiggles were studied. The extracted wiggles had a pulse width of from 40 to 80 ns, and an amplitude of from 10 to 30 μV Their positions in the reproduced waveform were shifted by an external magnetic field, but the wiggle width and amplitude were not affected. After awrite operation, the wiggle pulse width and amplitude changed; but, the area under the extracted pulses remained constant. Shifts in the peaks of reproduced waveforms increased when wiggles were close to the peak of the reproduced waveform, and the wiggle amplitude increased.