This circuit is from a manual from the 80's and the operational one used, uncommon nowadays, can be replaced by a modern equivalent. The power supply must be symmetrical.
The circuit is from Motorola's Linear Databook from 1990, but the configuration is current because...
In the figure we have the simplest way to implement a power supply for a tunnel diode. The...
This circuit was found in documentation from the 1980s. The circuit can be implemented with other...