This bench circuit was found in Radio Electronics magazine from June 1958. The circuit does not have an external power supply. The circuit generates signals from 12 Hz to 180 kHz in 4 bands.
This 1970s RCA circuit can be triggered by light or dark, depending on how the LDR is connected....
This circuit has more historical value than practical, unless the reader find all the components...
This circuit makes use of an old Texas Instruments component. The buzzer is also from the era. The...