Abstract: A frequency scan radar system is provided which scans in groups of nine contemporaneous beams which partially overlap in angular coverage in the plane of scan, such that any given target is illuminated by at least two of the beams. Receiving means separates echoes according to frequency (which relates to angle) in nine corresponding channels. Logic circuitry is employed to determine presence of signal in one or more channels. Bona fide echo signals occur in not less than two adjacent channels, whereas limited spectrum interference or jamming signals occur in only one channel. Video blanking means are controlled to blank out video corresponding to such single beam reception.