1940s commercial receiver (T1618E)

This receiver was found in a Radio Electronics from 1949. It is a superheterodyne of the time using 6 tubes.

Dual Voltage Reference LT1112 (CB4924E)
We found this circuit in an American 80's documentation. The resistors must be of high precision...
Static switch (CB7294E)
This circuit was suggested by General Electric in documentation from the 80s. SCRs are common...
Colpitts Oscillator (CB4735E)
This is a possible setting for a Colpitts oscillator operating in the audio track. The shunt coil...