This two-tone decoder has a bandwidth of 24%. The circuit is from a 1994 Electronics Now. The components without the value determine the recognized frequency.
This configuration is from a 1964 US documentation valid for any FET. The range of power voltages...
Only the right combination of the positions of the 6 rotary switches of 1 pole x 10 positions of...
Another of the many anti-bounce circuits that we have in this section of our website. This one...