This circuit uses an 18 MHz crystal to generate 36 MHz signals. We found it in an 80's documentation. The circuit has an input for frequency modulation.
This circuit, which in our times would be called a shield, can also be used with other loads. The...
This circuit is from an old American documentation from the 70s. Transistor 2N3904 can be replaced by...
This application of the 555 was found in the November 1992 Radio Electronics magazine. The...