With this circuit of a Popular Electronics from the 90's it is possible to test a diode with the oscilloscope visualizing its characteristic curve. The transformer can have currents starting from 100 mA.
This fuzz distortion circuit was found in old RCA documentation. Equivalent transistors may be...
This circuit with transistors of the time was found in the magazine Radio Electroinics of June of...
Several versions of this circuit can be found on this website. This makes use of FETs that can...