This circuit allows the detection of RF signals using the lowest range of direct currents of a common multimeter. Equivalent diodes such as 1N34 can be used. The circuit is assembled in a ballpoint tube.
Found in a 1968 American documentation, this circuit generates 1 kHz signals. The SCR used is not a...
This circuit with bass and treble control and 10 W of power per channel is from the SGS manual of...
More modern operational amplifiers can be used on this instrument to measure alternating voltages. The...