We found this power supply in the 1982 SGS Linear Integrated Circuits manual. The L296 is not common today, but if found it results in an excellent switching source with good stability.
The transistors are 2N918, 2N3464 and other RF equivalents of the time for Q1. For Q2, 2N3399, 2N2894...
This circuit, which can be used as a shield, was found in a 90s Electronic Design. The circuit...
This interesting intercom circuit was obtained from an Argentine publication from the 1970s....