Aplitude modulation radio broadcasting: Application of companding techniques to the radiated signal

A power-saving technique which may be applied to double-sideband amplitude modulation transmitters is described. The technique operates by imposing dynamic compression on the raidated signal, and relies on the action of receiver automatic-gain-control circuits to compensate for this compression at the receiver. It is suggested that use of the proposed technique could result in considerable power saving with minimal effect on the quality of reproduced programs. An extended field trial should be conducted using a representative high-power transmitter, to prove the system fully before an extensive introduction in service is put into effect.