This interference rejection circuit for telegraphy was found in a 1980s documentation for radio amateurs. The integrated circuits used are common today.
Found in a 1967 American publication, this circuit with feedback for two transistors has a gain of...
This circuit was found in an Elektor from the 90s. Next to the circuit we have a table with the...
In the figure we have the way to implement the E (AND) function with two inputs, in the case of...