This circuit takes advantage of the noise generated at the reverse biased junction of a germanium diode. Other types of diodes can be used. The signal is weak.
Found in a 90s Radio Electronics this circuit requires precision resistors in the dividing...
Mouser Electronics is already providing new MOSFETs EF SIHx28N60EF of Vishay series for voltages...
The LMV321 is a low voltage operational amplifier from ON Semiconductor. The following diagram,...