This circuit has its frequency controlled by a 1MHz crystal. The circuit must be powered by a voltage of 5V. The capacitors must be ceramic. The generated signal is rectangular.
Found elsewhere in this section, this circuit is from the April 1971 Radio Electronics magazine. Note...
With this circuit, a relay can be activated from an alternating signal with frequency up to a few...
The sound of this experimental musical instrument is produced by the movement of the hand in front...