| 摘要 |
PURPOSE:To improve the maximum output level characteristics and to reduce the level fluctuation due to change of a bias current, by applying the treatment to give a low level permeability to a magnetic core half which is provided at the downstream side of the traveling direction of a magnetic recording medium. CONSTITUTION:Magnetic core halves 1 and 2 use the same material, and the treatment is applied to give a low level permeability to the half 2 which is situated at the downstream side of the traveling direction of a magnetic tape 5. For an example of the treatment to give a low level of permeability to the core half, an internal strain is produced by the half 2 by applying previously the physical external force to the half 2. This internal strain lowers the level of permeability. Otherwise a heat treatment is applied to the half 2 or the degree of magnetic strain is increased, to lower the permeability. |
