This 5.1 MHz circuit was found in a 1980s documentation. The frequency is given by the crystal and general purpose transistors can be used.
The setting of this power supply is only 0.1%. We found it in a 1969 US documentation. Transistors...
We found this interesting transistor generator in European documentation from the 1980s. The...
The circuit shown in the figure uses two of the four operational amplifiers found on the LM324...