PURPOSE: To improve reception status, by controlling a reception circuit for remote control, and a display circuit which displays the desired channel of a reception television and a desired channel to be transmitted to a room, etc.
CONSTITUTION: When a user uses a portable television, the transmission channel of a booster is designated in advance, and when the user watches the television, reception is performed by fitting the reception channel of the portable television to the transmission channel. Therefore, since a selection TV channel desired by the user is frequency-converted to a vacant channel by a tuner 105, and an RF converter 106, no influence of an existing wave and wave interference is given. Also, by using a rod antenna as a transmission antenna 108 for customer, the length of the antenna can be adjusted corresponding to the wave of a transmission frequency, thereby, directivity, etc., can be also adjusted, and the appropriate setting of the booster based on an arranging position in a residence can be realized. In such a way, it is possible to perform gain control only for a desired channel, and to improve picture quality.