| 摘要 |
A frequency modulating circuit comprising a circuit for separating a synchronizing signal from an input signal, a circuit for generating a sampling pulse in accordance with the synchronizing signal, a circuit for producing a frequency modulated signal out of the input signal, and a circuit for detecting the phase of the frequency modulated signal at the timing of the sampling pulse. The level of the input signal is corrected in accordance with the output of the detecting circuit, so that the phase of the frequency modulated signal is locked to a predetermined phase at the timing of the sampling pulse. Consequently, despite frequency modulation of the wide-band input signal, the invention is capable of preventing occurrence of any moire pattern that may otherwise be caused in displaying the demodulated signal.
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