This circuit is intended for underwater communications. Of course, the critical point is the shielding to avoid water. The circuit is from an Electronic Hobbysts Handbook from the 90s.
Found in documentation from ON Semiconductor, this circuit provides a rectangular output signal with...
We found this circuit in 1964 General Electric documentation. The circuit works with mechanical...
This very low frequency circuit was found in a 1964 Electronic Design. Transistors may be modern...