| 摘要 |
PURPOSE:To attain stabilization of the characteristic and to decrease the man- hour for manufacture by giving a winding to a bobbin having plural guards and terminals with transposition and split phase, grounding one end to the terminal and grounded and winding the other end to a projection provided to the circumferential ridge of the guard so as to use it as an open end. CONSTITUTION:The winding is given to the bobbin 21 having plural guards 22 and a terminal board 23 with transposition and split phase via a slit of the guard 22 and the one end 24 is connected to the terminal 25 implanted to the terminal board 23 so as to be grounded. The other end 29 of the winding is wound to a concaved part 27 of the projection 28 provided to the circumferential ridge of the guard so as to form the open end and helical coils 30, 30' and 30''. The coils 30-30'' are contained in a shield case having a connecting window 31 and a shield plate 32 and an input coil and an output coil are wound respectively to the coils 30-30'' so as to form a video intermediate frequency helical filter. Since the winding is split by the guard 22 and the open end 29 is wound to the projection 28, then no variation of the characteristic due to the variation of the winding interval exists and no wire fastening agent such as compound is required, allowing to improve the productivity. |
