DISCRIMINATING METHOD OF PROFICIENCY OF RECORDING STATE OF VIDEO TAPE

摘要

PURPOSE:To achieve a simple discrimination without losing functions, by discriminating the proficiency of recording state depending on the presence or absence of an RF signal and a synchronizing signal in a signal FM-democulating a luminance signal. CONSTITUTION:An RF signal detecting circuit 6 detects the presence or absence of an RF amplifying signal from a preamplifier circuit 2. A synchronizing separation circuit 7 separates the synchronizing signal in an FM demodulation signal from an FM demodulation circuit 4, and a synchronizing signal detecting circuit 8 detects if the output of the circuit 7 includes the synchronizing signal. A discrimination circuit 9 discriminates it as failure if the synchronizing signal from the circuit 8 or the RF amplifying signal from an RF signal detecting circuit 6 is missing, to operate an alarm device 14.