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 consists of a test oscillator for medium and high power NPN transistors. For PNP,...
This is a complete version of the previous circuit, with several scales and two transistors, one...
Found in a 1965 Electronic Design, this circuit makes it possible to select signals with an...