This receiver was found in a 1924 book by Gernsback. The circuit uses three tubes and is powered by 3 batteries of different voltages, common at the time.
This circuit needs only 0.7 V at 40 uA to drive the relay. We found it in the November 1993...
This reflex receiver was obtained from a 1963 documentation. The transistors are germanium, and...
Obtained from an Electronic Engineering of the 90s, these circuits can be applied to almost any...