| 摘要 |
PURPOSE:To use an amplifier of a comparatively low frequency narrow band, by amplifying a mixed output of an intermediate frequency signal obtained by dividing the frequency to 1/N and a sweep local oscillating output, and thereafter, multiplying it to N times, and obtaining a tracking output. CONSTITUTION:In case of executing a spectrum analysis, an input signal is mixed with an output from a sweep local oscillator 20 by a frequency converter 16, and thereafter, is supplied to a cathode-ray tube 32 through a band-pass filter 24, a frequency converter 18, a band-pass filter 25, an amplifier 27, a detector 29 and a logarithmic amplifier 28. On the other hand, in case of measuring a frequency characteristic, an output of a local oscillator 22 of frequency being equal to the second intermediate frequency is mixed with an output of a local oscillator 21 by a frequency converter 9, it is inputted to an object to be measured 11 through a variable tuning band-pass filter 37 whose tuning frequency is set in accordance with a filter 26, a 1/N frequency divider 35, a frequency converter 40, a wide band amplifier 38, a frequency multiplier 36 and sweep voltage, and an amplitude characteristic for frequency of the object to be measured 11 is displayed. |
