Eighty years ago this month, the June 1939 issue of Radio Retailing carried this ad reminding dealers that they should stock up on portables for campers, collegiate-ers, picnic-ers, and swingsters.
The set shown is the Model 590-1. The superheterodyne set featued a tube lineup of 1A7G, 1N5G, 1H5G, and 1A5G, with a 35Z5GT rectifier for use at home. The set switched automatically from household current to battery by removing the line cord.