Found in documentation from the 1980s, this highly sensitive circuit is based on the conduction by the presence of gas from an ionization chamber. The components are from the time.
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...