Rapid tuning radio or TV receiver - has comparator comparing adjustable frequency divider's output with reference frequency and time constant circuit (NL 28.12.77)

摘要

The radio or t.v. receiver has a comparator to compare the adjustable frequency dividers output with a reference frequency. A time constant circuit has its time constant altered by a given circuit so that tuning takes place more rapidly than it would if the receiver were already tuned to the wanted frequency. The v.c.o's control circuit is able to respond relatively quickly to time the receiver to the wanted station and there after relatively slowly to keep it tuned.