This is a really interesting product, but I must confess to having no understanding of how the Postcard Radio works. It is based on radios from the 1920s and looks just like a postcard, except slightly thicker.
According to Middlesex University who produce the radio ‘it works without batteries and is tuned by moving a small metal plate or coin over the front of it’. It would make a good gift for wannabe spies who like gadgets disguised as everyday objects. The version with a picture of Winston Churchill on it, adds to the wartime espionage image.
It is available to buy from the Middlesex University Teaching Resources website.