1940s commercial receiver (T1618E)

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

Darlington Conventional 6N13 (CB1557E)
In the figure we have the configuration of the circuit as a conventional Darlington. In this...
Low Power CMOS Alarm (CB4779E)
We found this circuit in a 90's Radio Electronics. The low power circuit activates a 12 V relay...
10 W-Transistor Amplifier II (CB998E)
We found this amplifier in a 1990 documentation. The transistors are common, having been made...