This circuit was found in a 1981 documentation. The circuit produces intermittent beeps serving two oscillators, one of which is used to determine the tone of the beeps in which the C1 capacitor is responsible for the effect obtained, and a lower frequency oscillator than determines the intervals between the beeps. In this, the component responsible for the effect is C2. The circuit is powered by a voltage of 6 V that can be obtained from 4 common batteries connected in series. The two oscillators have controls that allow you to change the tone of the sound over a wide range, and the beep intervals. These components are potentiometers R2 and R3. The author originally used transistors of type 2SB77 that are PNP of germanium and PE107 that are NPN of silicon in its assembly.
