This circuit is from a 90s Radio Electronics. The resistors must be precision types and the transistor is a general-purpose type. The operational admits equivalent.
Found in a 1969 documentation, this circuit consists of a multi-oscillator with neon lamps....
This high-performance circuit was found in the 1982 SGS Linear Integrated Circuits Manual. The...
We have in the diagram another way to make the null adjustment of an operational amplifier. In...