PURPOSE: To perform the switching control of the making on/off of supply of a DC power source to a BS converter at an adaptor by connecting capacitors for DC cutoff on the input and output sides of an amplifier in the adaptor, and providing a bypass circuit.

CONSTITUTION: The capacitors 42 and 43 for DC cutoff are connected to the input and output sides of the amplifier 41 in the adaptor 4, and also, the bypass circuit consisting of a switch 44 and choke coils 45 and 48 is connected. Therefore, for example, a DC voltage of 15V is inputted from the output connector 47 of the adaptor 4 via a coaxial cable 5 by turning on the switch of DC output at a BS tuner 6, and it is applied on the amplifier 41 via the coil 45. At this time, the DC voltage is outputted from an input connector 46 and is applied on a BS converter 2 via a coaxial cable 3 by turning on the switch 44, however, by turning off the switch 44, no DC voltage is outputted to the cable 3. Therefore, a power source can be supplied from the tuner 6 to the adaptor, and also, respond to individual reception, etc.