LT123 Low Voltage Linear Regulator (CB4399E)

The circuit presented is from the 1993 Linear Technology Applications. The components used were common at the time.

RF amplifier (CB20045E)
The transistors are 2N918, 2N3464 and other RF equivalents of the time for Q1. For Q2, 2N3399, 2N2894...
Sensitive triac controller (CB7864E)
This circuit, which can be used as a shield, was found in a 90s Electronic Design. The circuit...
Transistorized Push-Pull Intercom (CB11210E)
This interesting intercom circuit was obtained from an Argentine publication from the 1970s....