Abstract: A radio receiver (102) receives on a selected one of a plurality of channels, one of which is a control channel. A continuous signal is transmitted on the control channel. A frequency synthesizer (122) includes a voltage controlled oscillator (VCO 124) and a plurality of phase lock circuits (126), such as a phase detector (130), a reference oscillator (134), a programmable divider (128) and a loop filter (132). The input of the VCO can be switched between the phase lock circuits and an automatic frequency control circuit (AFC 114), which is connected to the radio receiver. When the radio receiver is receiving a quality control channel signal, the switch is positioned to select the AFC circuit and, consequently, the VCO is frequency locked to the control channel signal. Whenever the VCO is locked to the control channel signal, one or more of the phase lock circuits are deactivated, thereby reducing power consumption.