Found in a 1980s American documentation, this crystal-controlled oscillator generates 100 MHz signals. The crystal used is 20 MHz. Modern equivalent transistors can be used.
This is the traditional configuration of an unregulated bridge rectified power source. The circuit...
The current accross the LED as function of the resistor value is given by the formulas. The...
This circuit for receiving or transmitting low power was found in old American documentation. It is...