Pye Band III converter, type F124, made by Pye Limited, East Anglia, England, 1955-1960.
Until 1955 the BBC transmitted the only television service in the UK, transmitted on Band I. However, in 1955 the commercial channel ITV launched, transmitting on Band III. Many people already owned televisions that were only designed to receive the BBC’s Band I service. Conversion boxes, like this example, allowed those users watch the new channel on their old television. Convertors were not perfect and the picture could be affected by unwanted patterns interference from electrical signals.