Like the previous circuits, this one uses a small speaker as a microphone and has two amplification stages with 600-ohm output.
This circuit was found in a 1987 magazine. It generates signals in a range from 100 kHz to 10 MHz,...
This circuit was obtained from an Electronic Design from 1964. Transistors admit modern...
This circuit can generate audio signals at frequencies ranging from 0.01 Hz to approximately 20...