| 摘要 |
PURPOSE:To attain simple and stable measurement by changing sequentially and periodically a frequency of a local oscillation signal used for the frequency conversion in response to a broadcast channel until an output of a narrow band amplifier appears and discriminating a reception channel depending on the channel selection point when the output appears. CONSTITUTION:A distributor 8 is provided on the way of a cable 4 connecting a BS converter 3 and a BS tuner 5 in a satellite broadcast reception system provided with a BS antenna 2, the BS converter 3, the BS tuner 5 and a television receiver TV so as to extract an oscillation signal leaked from a local oscillator in the inside of the BS tuner 5. The signal is subject to amplification 9 and frequency conversion 10, then fed to a narrow band amplifier 17, and the frequency of the local oscillation signal (l) used for the frequency conversion 10 until the output of the narrow band amplifier 17 appears is changed sequentially periodically in response to the broadcast channel and the reception channel is discriminated depending on the channel selection point when the output appears. |
