Some Distinctive Properties of Magnetic-Recording Media
R. Herr, B. F. Murphey, W. W. Wetzel · Journal of the Society of Motion Picture Engineers · 1949
Information is presented relative to the adjustment of bias current in magnetic recordings and the various effects of bias changes on distortion, frequency response, overload characteristics, and permanency are discussed. Other factors which influence frequency response are outlined briefly and it is shown that the inherent frequency response of the medium is difficult to divorce from effects due to the recording system. The problem of noise is presented in general terms and the nature and level of the noise from a direct-current saturated medium is advanced as an important criterion of quality.