| 摘要 |
PURPOSE:To prevent illegal wathing at low cost by providing a filter to every PAY channel block and allowing a switch circuit to control whether the supply of a PAY channel to each home is permitted or not. CONSTITUTION:A CATV signal obtained through a trunk line cable 11 is distributed into respective channels by a distributor 12 and PAY channel block filters 13, 14, 15..., and furthr distributed by a distributor 16 to a fixed contact of a corresponding switch in an RF switch group 17 having one switch element for each home (terminal). A signal appearing at the side of the movable contact of this switch is led to a mixer 18 provided corresponding to each home, further passed through a mixer 19 for normal channel mixing, and sent to the home. Said switch group 17 is turned on and off under the control based upon the operation of a control box 23 and a desired PAY channel is supplied to each home. |
