This circuit was found in a 1967 Electronics World. Transistor Q1 can be a TIP321 and Q2 can be a BC558. The indicator lamp is optional.
This circuit allows the measurement of very weak currents indicated on an analog instrument or...
Found in National Semionductor documentation this circuit combines a tone control with an...
Found in a 73 magazine from the 1980s, this circuit generates signals from 3.2 to 22 MHz. FETs can be...