Asymmetric-Sideband Broadcasting

There is described a method of radio transmission designed to economize frequency space in broadcasting, wherein one sideband and the carrier are transmitted, together with the lower audio-frequency components of the other sideband. By retaining the lower frequencies of the second sideband there is minimized the distortion to which pure single sideband gives rise in the types of broadcast receivers now generally used. Instead of first setting up the usual double-sideband transmission and then filtering out the undesired high-frequency components of one sideband, the asymmetrical spectrum is produced by combining a double-sideband modulation of the lower frequencies only with a single sideband of the upper range of frequencies. Details of an experimental application of the method are given.