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.
The circuit presented generates pulses at regular intervals with the duration controlled by a...
Found in Electronics Now, this circuit generates signals for testing like a signal injector. The...
This simple expandable circuit was obtained from a Popular Electronics from the 80's. The supply...