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.
Suggested by Siliconix in documentation from the 90's, this circuit supports current equivalent...
This circuit decodes a 1800 Hz tone used in communications. The circuit is from an American...
This circuit was obtained in 1981 documentation. It is an FM transmitter that can serve to emit...