Found in na 1969 Electronics World, this circuit makes use of transistors of the time. Equivalent transistors can be used. The diodes can be 1N4004.
This circuit was obtained from an American 80's documentation. The balanced mixer can be shown in...
Found in a 90s Electronic Design, this circuit generates harmonics from a sinusoidal input signal....
Published in an old Popular Electronics, this circuit makes use of components that are still...