The characteristics of magnetic recording heads and tapes

The paper deals with the functions, operating conditions and characteristics of magnetic heads and tapes. It is shown how a recording by magnetic means is made, retained on the tape and finally reproduced. The erasing of a magnetic tape by means of a steady or an alternating magnetic field is explained. The recording process is considered together with the effects caused by a.c. biasing. Formulae for obtaining the output voltage from any given head are discussed. Demagnetization, gap functions and the various losses encountered in tape reproduction are also dealt with. Tape characteristics are discussed together with comparison graphs for different tape characteristics. Some recording heads, which differ from conventional designs, are described and their applications for various types of magnetic recordings considered. Finally, the effect of head and tape wear on the frequency response of a recorded tape are discussed quantitatively.