This paper will describe the electrical and physical features of the 55A radio receiver and certain associated apparatus, which were designed for use in BELLBOY personal signaling systems operating in the 150-mega-cycle common carrier band of frequencies. The receiver is pocket-sized and provides, in effect, an extension of the telephone bell to the customer's pocket so that he may be alerted while away from his office, home, or base location. Аn incoming signal, bearing the customer's specific code, triggers the receiver. The receiver then emits ^continuous tone, in response to which the customer calls his base telephone to receive his message, or responds in some other prearranged manner.