This high gain circuit is from 1969 General Electric documentation. The transistors are of the time, but equivalent types can be tested.
Other operational ampliers series, such as MC34072, MC34074, MC35071, MC35072, MC35074 d MC33071 can...
This circuit is from a NEC megaphone made in Japan in the 60s. The circuit has 4 W of power and...
This benchtop AC and DC power source was published in the December 1957 Radio Electronics...