This is a 1960s amplifier setup found in a period publication. The circuit uses a special driver transformer that inverts the phases of the signal to excite the output transistors.
In the figure we have the traditional configuration of a phase shift oscillator that produces a...
This circuit produces an intermittent sound in a ceramic piezoelectric transducer, for example, a simple...
If you have a common analog multimeter, you can increase its input resistance in the measurement of...