The FETs of this circuit can be the BF245. The circuit is from an old documentation and can be used in the amplification of infrasonic waves, of a sonic attack, for example.
This high-performance circuit was found in the 1982 SGS Linear Integrated Circuits Manual. The...
Found in a 90s Electronics Engineering, this circuit makes use of components of the time. The...
Found in a magazine 73 for radio amateurs, this circuit has two settings, one for the interval and the...