This configuration appears at several points in this section, obtained from different sources. This is from American documentation. The gain is 20 and the transistor can be a BC549.
Found in a 90s Popular Electronics, this circuit excites a 40 kHz ultrasonic transducer. The...
Found in Popular Electronics, this configuration can be powered by voltages from 6 to 12 V....
This circuit can be powered from 4 to 12 V sources. Pin 6 is the positive supply. See more about...