An apparatus for repeating signals, the apparatus comprising: a receive antenna configured to capture a receive signal; processing circuitry (40; 70) configured to process the receive signal to form a repeated signal; a transmit antenna configured to transmit the repeated signal; wherein the receive signal includes both an input signal to be amplified and re-transmitted and a feedback signal that is fed back from the transmit antenna; the processing circuitry including: decorrelation circuitry (44; 80) configured to modify the repeated signal and including frequency shifting circuitry operable to create a frequency shift in the repeated signal with respect to the receive signal to form a repeated signal that is frequency shifted and decorrelated from the receive signal; gain margin circuitry configured to constantly measure a gain margin for the apparatus utilizing the decorrelated receive and repeated signals (38; 37), wherein the gain margin comprises a difference between an isolation of the antennas (32; 36) and a gain of the apparatus, wherein the gain margin circuitry is configured to determine a ratio of a relative level of the input signal in the receive signal compared to a relative level of the feedback signal in the receive signal; gain circuitry (42; 78) configured to automatically adjust gain in the decorrelated receive and repeated signals (38; 37) based on the gain margin to compensate for variation in gain margin. a receive antenna configured to capture a receive signal; processing circuitry (40; 70) configured to process the receive signal to form a repeated signal; a transmit antenna configured to transmit the repeated signal; wherein the receive signal includes both an input signal to be amplified and re-transmitted and a feedback signal that is fed back from the transmit antenna; the processing circuitry including: decorrelation circuitry (44; 80) configured to modify the repeated signal and including frequency shifting circuitry operable to create a frequency shift in the repeated signal with respect to the receive signal to form a repeated signal that is frequency shifted and decorrelated from the receive signal; gain margin circuitry configured to constantly measure a gain margin for the apparatus utilizing the decorrelated receive and repeated signals (38; 37), wherein the gain margin comprises a difference between an isolation of the antennas (32; 36) and a gain of the apparatus, wherein the gain margin circuitry is configured to determine a ratio of a relative level of the input signal in the receive signal compared to a relative level of the feedback signal in the receive signal; gain circuitry (42; 78) configured to automatically adjust gain in the decorrelated receive and repeated signals (38; 37) based on the gain margin to compensate for variation in gain margin. decorrelation circuitry (44; 80) configured to modify the repeated signal and including frequency shifting circuitry operable to create a frequency shift in the repeated signal with respect to the receive signal to form a repeated signal that is frequency shifted and decorrelated from the receive signal; gain margin circuitry configured to constantly measure a gain margin for the apparatus utilizing the decorrelated receive and repeated signals (38; 37), wherein the gain margin comprises a difference between an isolation of the antennas (32; 36) and a gain of the apparatus, wherein the gain margin circuitry is configured to determine a ratio of a relative level of the input signal in the receive signal compared to a relative level of the feedback signal in the receive signal; gain circuitry (42; 78) configured to automatically adjust gain in the decorrelated receive and repeated signals (38; 37) based on the gain margin to compensate for variation in gain margin.