| 摘要 |
PURPOSE:To lessen the leakage of a local oscillation signal from an antenna terminal by making use of reverse attenuation, by providing the input circuit of the tuner of a TV receiver with an isolator. CONSTITUTION:The 1st and 2nd input terminals 1 and 2 receiving high frequency signals are provided and high frequency signals supplied to input terminals 1 and 2 are selected through the operation of switch circuit 16 and supplied to a VHF tuner part of UHF tuner part by way of branching filter 3. When a signal from a cable TV circuit is received at this input terminal 2, terminal 2 is provided with isolator 15 or a broad-band amplifier and the reverse attenuation of this isolator 15 or the broad-band amplifier is utilized to prevent the oscillation output of local oscillator 13 from leaking from input terminal 2. |
