A method and apparatus for self-testing a GSM/EDGE communications device. An embodiment provides a method of measuring transmit power. A receive phase locked loop (PLL) is inserted into a feedback receiver local oscillator mixer. The receive PLL is then tuned to a local oscillator frequency. Once the tuning is complete, an I and a Q signal are captured using a channel of the feedback receiver. After capture, a I2+Q2 sum is computed, measuring the transmit power. The feedback receiver automatic gain control (AGC) may be used to determine transmit power in place of I2+Q2. The apparatus includes: a modem assembly, a power control assembly, a power amplifier, a duplexer, a coupler and a switch. The power control assembly further includes a first PLL and first and second mixers. The second mixer is connected to a feedback low noise amplifier and receives input from a feedback receiver PLL.