These gentlemen 75 years ago were purchasing their power lunch from a coin-operated vending machine capable of dispensing hot dogs, hamburgers, or grilled cheese sandwiches. The picture appeared in the March 1946 issue of Radio Craft, which points out that the machine was only slightly larger than the usual soft drink or cigarette machine, and operated from a standard 117 volt outlet.

The food was heated by radio waves, from “two specially developed high-frequency power oscillator tubes.” In other words, the machine was an early version of the microwave oven. THe engineers toiled long and hard to develop the machine. In particular, the choice of frequency was problematic. Some frequencies would heat the roll but not the frankfurter. Other frequencies would heat the frankfurter but burn the bun. Finally, however, a frequency that was just right was found, and the machine was put into production.

While we recognize this dialectric high frequency heating to be the principle employed by the modern microwave oven, the magazine cautioned that home ovens were not just right around the corner:

It should not be construed from this development that the electronic stove is just around the corner, electronic engineers hasten to explain. The canteen grill and the electronic stove present two different kinds of problems and the accomplishments in the development of the former should not be interpreted as solving the problems yet to be overcome in the field of electronic cooking.

The two in the picture are identified by the magazine as Messrs. Baker and Leverone, first names not given. They are associated with General Electric and Automatic Canteen, the companies responsible for the new machine.  Leverone is probably Nathaniel Leverone, the founder of the vending machine company.