| 摘要 |
PURPOSE:To accurately measure and analyze a mixed wave without being affected by a video signal component by employing fast Fourier transform spectrum analysis for an interference wave signal extracted by separating a TV signal into an upper and a lower band component. CONSTITUTION:A high-frequency input to be observed is inputted to a receiver 1 and an converted IF signal is passed through respective filters BPF3-BPF5 for picture quality monitoring, upper-band observation, and lower-band observation and becomes video signals V0-V2 in respective frequency bands through synchronization detectors 7-9. The signals V0-V2 are video-recorded temporarily on a VTR 18 by initiating interruption by sampling 10H and 11H, and 12H and 13H of the signals V1 and V2 by switches 11 and 12 in vertical blanking periods, e.g. 10H-13H of the signal V0. The video signals for observation which are video-recorded as mentioned above are A/D-converted in a 10H-13H period including an interference wave for measurement by an A/D converter 19 and a gate pulse generator 20 and transferred to a CPU 21, and an FFT board 22 takes a spectrum analysis to measure and analyze the interference wave.
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