Found in a 1967 Electronics World, this oscillator changes its tone when objects move in their environment. The output is made on a low impedance phone.
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...