This receiver is an unflown example of part of the V2's on-board guidance system. The A4 (V2) rocket, developed by Germany during the Second World War, is considered to have begun the era of ballisitic missiles used as a weapon. Some versions were controlled by radio signals from the ground during launch, to keep the rocket on course as it ascended through crosswinds. An on-board receiver, such as this one, took these signals, mixed them with information taken from on-board gyroscopes, and directed control signals to the vanes in the rocket exhaust to steer the rocket.
It was donated to the Smithsonian by Helmut Hoelzer, its inventor and one of the German engineers who worked on the V2.