Distributions and characteristics of spike noise in double-layered perpendi
cular recording media were investigated using a spin-stand and a digital st
orage oscilloscope. It was revealed that spike distributions are strongly d
ependent on the soft magnetic underlayer material and that the reproduced s
ignal amplitude is modulated at the spike positions. (C) 2001 Elsevier Scie
nce B.V. All rights reserved.