We found these circuits in a 90s Radio Electronics. In them, we have the way to turn a load on and off using pressure switches. The circuit can be used with other types of direct current load.
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...