Double Track Video Heads for Magnetic Disk

The crosstalk, electromagnetic conversion, and service life characteristics of two-channel gap inline heads with Sendust bulk head structures (track width 60 ¿m, gap 0.2 ¿m) are discussed. When the mutual inductance between heads M is small, crosstalk occurs during reproduction but not during recording. By reducing the core size, M was reduced, lowering the crosstalk level during reproduction. Studies of the gap depth dependence of the reproduction output indicated that reducing the gap depth by 20 ¿m would only result in an output increase of 3 dB, but would have adverse effects on the head life and reliability due to friction.