This circuit was obtained in a QST magazine from the 90s. The circuit makes use of components that are uncommon today. The circuit includes a gain selection switch.
This circuit was found in an English publication from 1989. The integrated circuit is an...
This circuit was obtained from a 1964 magazine and has some interesting features such as the input...
Using a general-purpose transistor this AC amplifier was found in the November 1993 issue of...