Generally speaking, methods and apparatuses which correct errors related to phase and gain imbalances in quadrature tuners are disclosed. The quadrature tuner may be online and operating, receiving data. An embodiment may generate a squared signal from the IF frequency signal of the tuner. In generating the squared signal, the embodiment may enable the extraction of phase error and gain error information of the IF signal. The embodiment may determine a phase error component, a gain error component, or both, by frequency translation. The frequency translation may involve down-converting the signal associated with the error component to direct current (DC) signals and enable the determination of the associated phase error and/or gain error. The embodiments may generate an adjusted signal via the IF signal by applying a phase correction signal or gain correction signal to components used to correct the IF signal.