1955 One-Tube Reflex Radio

Despite its nondescript looks, this one-tube broadcast receiver from 70 years ago was a good performer. It was designed to be small and efficient. It consumed about the same amount of power as an electric clock, meaning that it could be run constantly. And because of the low power consumption, it put out little heat and could be mounted in a wall or a piece of furniture, without having to worry about ventilation. It was said to put out enough volume to fill the room, but not enough to bother the neighbors.

When tested 100 miles from Chicago, it pulled in all of the major Chicago stations during the day with just a 12 inch antenna. This was accomplished by reflexing the 6AU6 to serve as both RF and AF amplifier. A diode was used as detector, and the rectifier was selenium.  It appeared in the November 1955 issue of Popular Electronics.