FM TRANSMISSION CHARACTERISTIC MEASURING INSTRUMENT

摘要

PURPOSE:To measure simply the FM transmission characteristic in a short time by applying sweeping by a sweep start signal by a prescribed time after a timing signal applied after a program search signal changes suddenly synchronously each intermittent signal. CONSTITUTION:A measuring object 11 gives a reproducing signal to a spectrum analyzer (SA) 10 via a branching filter 21 and also the signal to an envelope detector 22 and a mark detector 23. The envelope signal from the detector 22 and a program search signal from a detector 24 is inputted to a sweep control circuit 24 as a measuring start signal. The sweep start signal is generated after a prescribed time from the leading of the envelope signal from the circuit 24 after the measuring start signal is applied thereto and the signal is fed to a sweep voltage generator 19. The sweep voltage generator 19 generates a sweep signal and the result of measurement is displayed on a cathode ray tube 17. The sweep voltage generating circuit 19 uses the sweep start signal given after one sweep and a blanking time end to start the next sweep. The processing above is repeated to display a reproducing FM signal inputted to the SA 10 continuously.