This circuit from General Electric was found in a 1967 documentation. The SCR is of the time, as are the transistors, but equivalents can be used.
This circuit is from a manual of FETs of 1977. The FET can be the BF245 or MPF102 and the relay is of...
This high impedance step suggested by an English publication can operate up to 1 MHz with 1 V rms...
This circuit generates sine low-frequency signals. The frequency depends on the twin-T network....