This is another of the Star Trek red alert circuit that you can find on this site. We took this version from an English publication from the 80s.
In the figure we have the typical configuration of a sinusoidal audio oscillator with twin-T. The...
This timer was found in English documentation from the 80's. The integrated circuit is common...
This circuit for monitoring telegraphy transmissions was found in a 1975 CQ magazine. Transistors may be...