Multipurpose temperature control (CB21368E)

This circuit was found in a 1967 RCA SCR manual. It uses period components that can be replaced with modern equivalents.

Oscillator for the medium wave range (CB21140E)
This ground-based circuit was found in 1990s American documentation. The transistor can be any...
Automotive Immobilizer (CB24479E)
We found this circuit in a Radio Electronics issue from November 1976. The circuit is for vehicles of...
AM Modulator 78xx (CB15167E)
With this circuit it is possible to obtain a voltage modulated in amplitude with a maximum current of...