This crystal oscillator generates a 20 MHz signal. Equivalent transistors such as BF494 and 2N2222 can be used. The stabilizing diodes can be 1N4148.
We found this sensitive moisture detector in an old documentation. The circuit uses a common JFET,...
This simple 2-transistor radio is from Radio Electronics in October 1952. The circuit outputs a...
This circuit was obtained in an American documentation of 1964. The transistors are of the time....