The setting of this power supply is only 0.1%. We found it in a 1969 US documentation. Transistors may be current equivalents. Note the use of symmetrical power supply.
We found this circuit in a 2003 documentation. The purpose is to make the player choose one or two...
This circuit allows the frequency generated by an oscillator with the 4069 to be divided by two,...
This commercial transistor radio was manufactured by RCA in the 1960s. The circuit has only 4...