Noise-Whitening Filters For Digital Recording

mA. The device was deposited onto a polished glass substrate and sandwiched with a second polished piece of glass for prot~ection. At the peak in wavelength response (2 mils), an rnls output of about 25 mV was achieved. The response vanished into widebmd tape noise for a wavelength below 50 pin. A maximum rms signal-to-rms tape noise of about 66 dB wa.s observed. An applied bias field of about 60 Oe was required to linearize the device. Measured distortion characteristics of the head are comparable to ring head technology.