This simple general-purpose transistor mixer was taken from an article in Electronics Now magazine in March 1994. You can choose a low-noise transistor such as the BC549.
Found in a Popular Electronics from the 90s, this circuit uses components that are still current....
This circuit uses an operational that is not currently common. We found it in an old American...
This circuit was obtained from an Electronics World of 1968. The transistor may be general purpose and...