PURPOSE: To obtain a coupling circuit reduced at its loss by penetrating plural primary windings of which one end is used as input terminals and a secondary winding of which one end is used as an output terminal into a penetration hole of a ferrite core, and earthing the other ends of the primary and secondary windings.

CONSTITUTION: When a receiving signal from an exclusive television antenna is passed through filters 2a∼2c; only the signals of 8, 10 and 12 channels e.g. are inputted. Respective primary windings 3a∼3c are connected to the input terminals 1a∼1c. The primary windings 3a∼3c are bound together with the secondary winding 5 connected to the output terminal 4 and inserted into the penetration hole 6a drilled into the cylindrical ferrite core 6 and its leading end is earthed. In such a constitution, a coupling type transformer 7 is formed by the core 6, the primary windings 3a∼ 3c and the secondary winding 5 and respective 8, 10 and 12-channel television signals inputted from the terminals 1a∼1c are mixed and sent from the output terminal 4.