This circuit is from old documentation, but it can be implemented with modern transistors such as 2N2222 for bipolar and BF124 for FET. The crystal determines the operating frequency.
This powerful amplifier with 2N3055 transistors at the output provides a few tens of watts rms on a...
With this circuit it is possible to receive and send audio signals simultaneously over the same...
This circuit generates 100 MHz signals from a 20 kHz crystal. The circuit is from an 80's...