| 摘要 |
A radio wave receiving apparatus is provided with a tuning circuit for bringing a receiving frequency of an antenna tuned in to a frequency of a desired wave, a frequency converting circuit for mixing a local oscillation signal with the signal received through the antenna, thereby converting the received signal into an intermediate frequency signal, a feed back loop including at least a portion of the tuning circuit for feeding back the received signal, a controller for detecting a level of the intermediate frequency signal to change a frequency characteristic of the tuning circuit, thereby obtaining a tuning point corresponding to the desired wave, wherein, the controller brings the feed back loop in operation, thereby changing the frequency characteristic of the tuning circuit, and when two peaks of a level of the received signal are detected while the frequency characteristic of the tuning circuit is changed, the controller selects as a tuning point corresponding to the desired wave a tuning point at which one of the two peaks of the level of the received signal corresponding to a high-low relationship between the predetermined frequency of the local oscillation signal and the frequency of the desired wave is detected.
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