Seventy-five years ago this month, the September 1947 issue of Radio Retailing carried this ad for an interesting AM-FM receiver. The set, a mostly normal AM-FM superhet, wasn’t for sale to the public. It was instead billed as an instrument for use by the dealer to stimulate sales. The compact receiver could be taken to the prospect’s home to demonstrate how well FM signals could be received.

It had a signal-strength meter with two adjustable ranges, as well as a means for switching between the built-in telescoping antenna, and an outdoor antenna. Therefore, it was possible to tell whether an antenna would be necessary, and the best spot in the house to mount the set.