Satellite broadcast television receiver tuner circuit

摘要

PURPOSE:To simplify the adjustment by patterning an inductor of a pre-selector circuit onto a printed circuit board and providing a wire for coupling and adjustment of input/output of a signal to inter-stage. CONSTITUTION:A pre-selector circuit 6 of a tuner circuit is formed by patterning directly a primary inductor 21, a secondary inductor 25, an image trapping inductor 28, and an inductor 50 to input a local oscillation signal directly onto the printed circuit board. In the circuit 6 as above, the frequency of an image wave depends on the inductance of the inductor 28 and the capacitance between the inductors 21 and 28. Then in the mixer circuit 7 also, inductors 30, 43, 44 are formed by being pattern directly onto the printed circuit board. In the circuits 6, 7 of the constitution above, wires 47, 48 are provided for coupling adjustment of input/output of a signal to/from inter-stage. Thus, the coupling between the primary and secondary sides require no adjustment and the coupling adjustment of the input/output of the signal to/from the inter-stage is implemented by having only to move the wires 47, 48.