Hollywood AM CARD credit card sized am radio, Am card receiver, earphone and battery included, 2.5mm plug, frequency 540-1600 KHz

Hollywood AM CARD credit card-sized am radio, AM card receiver, earphone, and battery included, 2.5mm plug, frequency 540-1600 KHz This credit-card-sized radio represents an important stage in Sony’s development of miniaturized audio equipment. Its predecessors included the first pocket radio, the TR-63, developed in 1957, and the Walkman, introduced in 1979.

The electronics are all incorporated into one chip, which takes up only a fraction of the space inside the plastic casing. Most of the space is devoted to batteries and to the component that controls the tuning, called a capacitor. The capacitor was itself replaced by an even smaller tuning component, a tiny diode, in later models. The small size of all the components allowed the designer great freedom to choose the shape of the final product, making it resemble another familiar product: a credit card.

• Brand: SONY
• Color: Black
• Material: Plastic
• Model: CR501
• Titles: Credit card radio