Abstract: A class 1 cellular mobile telephone apparatus has an LCD display and keypad provided in a transceiver main unit, which can be installed directly in a passenger compartment of a motor vehicle. The handset unit contains only a speaker and a microphone, eliminating the need for a microprocessor and associated supporting circuitry. The additional space within the handset is utilized for placement of a battery pack power supply for transportable operation of the apparatus. The apparatus is smaller, simpler and lighter in weight than conventional class 1 cellular apparatus.

Abstract: A system for controlling the power level of RF signals output by a portable radio transmitter having a first voltage supply, a first amplifier stage and a microcomputer coupled to the first amplifier stage for selecting one of a set of power levels. An indicator signals when the radio transmitter is coupled to a vehicular voltage supply and, in response, the microcomputer generates a control signal representative of a desired power level. A second amplifier stage is coupled to the first amplifier stage and receives RF signals at the selected power level. A constant gain control circuit coupled to the second amplifier stage receives the control signal and responds by setting the gain of the second amplifier stage at one of at least two constant gain values so that the output RF signals are provided with the desired power level.