Micro metronome (CB20743E)

This simple CMOS metronome circuit can be mounted in a small box, providing both sound and light sources.

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....