This circuit is from a 1924 book by Gernsback. The receiver uses two tubes and listens to headphones. Power is supplied by battery with the indicated voltages.
This micro FM transmitter or wireless FM microphone makes use of a ceramic capsule as a microphone or...
The voltage of 30 V indicated in this project, shown in the figure depends on the diac used. It...
This circuit is intended to drive bistable relays and can be used as a shield for...