Abstract: A system for testing protection against spurious response interference in a radio receiver by imposing wide band interference signals. An interference generator (210) produces a wideband interference signal (220). This interference signal (220) is combined with a test signal (215) generated by a channel generator (205). This combined signal is received by the unit under test (235). The unit under test (235) is insensitive to the interference signal (220) and receives the result signal (240). The result signal (240) is compared to the test signal (215) to check for reception errors. If errors are detected, the wideband interference signal (220) is subdivided and retested in an iterative manner until the band is small enough to perform single frequency tests to locate the frequency causing the error.