Brownie crystal radio receiver and pair of Lisen headphones, mid 1920s.

For many early radio listeners, purchasing a receiver which came with a loudspeaker was prohibitively expensive. Instead, they would listen to programmes through headphones. A crystal radio sets was a simple and cheap option. It consisted basically of a tuned circuit and a crystal detector, and had no batteries, the power delivered to its headphones all coming from the transmitter. This radio was manufactured by the Brownie Wireles Co of Great Britain Ltd.