WM-F20

The WM-F20 was a compact expandable radio Walkman introduced in 1983, closely following the sliding cassette-case design of the WM-20 while adding FM and TV audio bands through an integrated tuner section. The expandable body kept the player unusually compact when closed, while reinforced hinges and a slide mechanism were adapted to support the added radio hardware. Users could switch between tape and broadcast listening without needing a second device, extending the appeal of the format without fundamentally changing how it worked.

It was less a headline model than an intelligent extension of an idea Sony already knew had appeal. Once the expandable format had proven itself, it made sense to carry it into the radio-equipped side of the range for users who wanted the same practical pocketability without giving up broadcast listening. Models like this are a useful reminder that much of the Walkman story was built not only on breakthroughs, but on careful, logical variations.