Abstract: A multi-superheterodyne receiver having a first local oscillator for generating a first local frequency signal, a first frequency converter for converting to a first intermediate frequency signal a received signal in response to the first local frequency signal, a second local oscillator for generating a second local frequency signal, a second frequency converter for converting to a second intermediate frequency signal the first intermediate frequency signal in response to the second local frequency signal, includes judging circuitry for judging if a residual spurious component is generated when harmonic waves of at least one of the local frequency signals are at certain frequencies.