1940s commercial receiver (T1618E)

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

Contactless inition (CB6386E)
This circuit is from an ancient American documentation. The transistors are of the time and the...
LC Oscillator Using the 40106 (CIR092E)
A high-frequency square wave oscillator using an LC-tuned circuit is shown here. The upper...
Protection for operational amplifier (CB6976E)
This circuit protects an operational amplifier with respect to both current and voltage. The...