This circuit was found in documentation from the 1970s. However, it can be implemented with modern transistors such as 2N2222 for Q1 and BF494 for Q2. The crystal depends on the desired frequency.
This circuit was found in an Electronics World magazine from 1990. The circuit can be mounted...
In the figure, from a documentation from the 70s, we have a few-watt amplifier for general use....
This circuit is from 1968 and consists of an amplifier for turntable of the time. The CA3020 was...