Sigmon developed a specialized radio receiver and reel-to-reel tape recorder. When the receiver picked up a particular tone, it would record the subsequent bulletin. At the time, the device cost about $600 (equivalent to $5,600 in 2018). The LAPD's chief, William H. Parker, was interested, though skeptical, warning the inventor, "We're going to name this damn thing Sigalert." More practically, he refused to use it unless the receivers were made available to all Los Angeles radio stations—it could not be a KMPC monopoly.