Abstract: A radio frequency amplifier module (500) has a voltage monitor (546) that monitors an input supply voltage of an input power supply (534) and an adjustable power supply (512) that accepts power from the input power supply (534) and produces an adjustable power supply output that has a controllable voltage. The radio frequency amplifier module (500) further has an amplifier (402) that is supplied by the adjustable power supply output and that amplifies a radio frequency signal. The radio frequency amplifier module (500) also has an output controller (546) that is communicatively coupled to the voltage monitor and the adjustable power supply (512). The output controller (546) controls, in response to the input source voltage, the controllable voltage of the adjustable power supply output.

Abstract: A method is provided for placing a call from a two-way radio subscriber unit operating within a two-way radio communication system (100). A user operates the subscriber unit in a call address search mode (310), and provides search criteria data that references a communication target (320). The search criteria data is transmitted in a query to system equipment which provides, in response, a list of matching identifiers and corresponding call addresses (330, 340). This list is presented to the user and a selection obtained (350, 360). A call address corresponding to the user selection is used to initiate the call to the communication target (370).