Found in a Philips publication from the 1970s, this circuit uses a DO040, which is difficult to obtain today. The circuit is powered by 12 V on pins indicated in the diagram.
This is the traditional unijunction transistor relaxation oscillator circuit for the audio band. The...
This is half of a 4-channel amplifier from a system published in the October 1971 issue of Radio...
This circuit works both as a grid-dip (transistorized) and as an oscillator. The circuit is from a...