MEASURING INSTRUMENT FOR INTERFERENCE SUPPRESSING RATIO ON ADJACENT CHANNEL AND CHANNEL ADJACENT TO THE ADJACENT CHANNEL

摘要

PURPOSE:To measure a ratio of suppressing disturbance with a high accuracy in a short time by using an electronic computer so as to correct residual noise and discriminating whether or not a curve is a monotonously decreasing curve. CONSTITUTION:The title instrument consists of FM signal generators 1, 2, a video signal generator 3, a sinusoidal wave generator 4, a switch 5, a fixed attenuator 6, a variable attenuator 7, a mixer 8, a branching filter 9, a satellite communication receiver 10, a spectrum analyzer 11, a band pass filter 12, a level meter 13 for video band, a monitor receiver 14, an amplifier 15 and an electronic computer 20. At the time of measuring an interference suppressing ratio on a channel adjacent to an adjacent channel, the electronic computer 20 corrects residual noise over a wider range irrespective of the level of an interference modulated wave to decide the presence of the occurrence of a different kind of cross modulation or the like. Thus, the interference suppressing ratio of an adjacent channel and a channel adjacent to the adjacent channel is measured with a wider range of interference modulated wave signal level with high accuracy in a short time.