A system and method for transmitting data communications through air using a radio. The invention allows the user to select from a number of predetermined output transmission powers. When a lower output transmission power is selected the current drain to the associated amplifier is decreased thereby conserving battery power of the radio. In addition, a detector diode circuit combined with an adjustable gain amplifier combine to provide a feedback mechanism whereby the output transmission power of the radio is held substantially constant over a broad range of temperatures.