Apparatus and methods degarble a received broadband radio signal using spatial filtering. The apparatus and methods use various garbled versions of the signal delivered by parallel processing chains assumed to have the same transfer function. Automatic equalization (4d), at the level of the outputs of the processing chains (2a to 2g), is performed before the spatial filtering (3). The automatic equalization reduces disparities, innate or originate from drifts over time, between processing chains (2a to 2g), and uses a local test signal generator (5).