Eighty years ago this month, the nation’s radio retailers were headed into the summer months, which had previously been known as the summer slump. But the April 1940 issue of Radio Retailing magazine noted that the portable set, really only two years old, had been responsible for the virtual elimination of the 1939 summer slump.

The magazine gave a number of pointers to promote the sets, which it pointed out could be marketed to those traveling by trailer, by plane, by boat (as shown below), or, as shown on the cover, by train.