Found in an American 1980s documentation, this circuit compares signals from two TTL sources, providing an output that depends on the frequency difference. The circuit can be used as a shield.
This circuit was published in the January 1975 issue of Radio Electronics magazine. An article showed...
This two-component circuit was suggested by Radio Electronics magazine in its August 1977 issue. The...
The traditional circuit was taken from a French magazine Radio Plans that no longer exists but can...