English: Farmer in 1923 listening to crop reports broadcast from Washington D.C. using a crystal radio. The early crystal radio had a "cat whisker detector" consisting of a fine wire on an adjustable arm that touched the surface of a crystal of the mineral galena, which had to be adjusted before each use. The user poked the "cat's whisker" wire around on the crystal surface until the device began working and the radio station was audible in the earphones. The information farmers heard through their earphones helped them decide what crops to raise and when to sell.