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 1960 Sylvania manual, this circuit can be implemented with a modern equivalent...
This configuration, already presented in other points of this section and website, is of a...
We found this precise crystal oscillator for the 144 MHz band, depending on the crystal used. The...