Fascinating Look Back at Credit Card-Sized Radios, Like the Casio RD-10, from the 1980s

Card radios, like the Casio RD-10, are basically compact, portable radio receivers designed to be roughly the size of a credit card or a small stack of cards, making them highly convenient for on-the-go use. These devices emerged during a time when miniaturization was a big trend in consumer electronics, particularly in the 1980s and 1990s, as companies pushed the boundaries of making gadgets smaller as well as more portable.

The 1.9mm thick RD-10 didn’t have an external telescopic antenna or a built-in one within its body, which would’ve bulked it up. Instead, the wire of the earphones doubled as the FM antenna, a common trick in compact radios of the time. Casio built upon its success with models like the RD-20, an AM-only version that was slightly thicker but still credit-card-sized, designed for those who preferred talk radio or AM broadcasts over FM music stations.

Beyond Casio, other brands dipped into the card radio craze. Citizen, a competitor known for watches, released its own FM Card Radio around the same time. It was slightly chunkier than the RD-10 but still pocket-friendly, weighing about 21 grams with its lithium battery. It shared a similar minimalist design ethos, though it didn’t quite match the RD-10’s “world’s thinnest” claim.
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