This receiver was found in a Radio Electronics from 1949. It is a superheterodyne of the time using 6 tubes.
This circuit uses two Raytheon RC4558 operational amplifiers that are similar to the 741. The...
This circuit works with only one battery, providing a range of a few tens of meters. We found it...
This circuit from the 40's is a conventional analog multimeter with several scales. Its accuracy will...