Drop=out detector for FM carrier in video recorder - has demodulator with special characteristics to detect drop=outs irrespective of direction and frequency

摘要

The drop-out detector for a frequency modulated carrier wave detects in a simple way all drop-outs irrespective of their direction, frequency and the instantaneous amplitude of the video signal, and always produces a pulse when a drop-out occurs. It uses a demodulator whose demodulation characteristics are relatively flat inside the wanted frequency range (11) and relatively steep outside it. The characteristic curve passes through a maximum and is symmetric about the centre frequency of the wanted range. The ends of the wanted range have roughly the same amplitude.