, a capture effect
is a phenomenon, associated with FM reception, in which only the stronger of two signals at or near the same frequency
will be demodulated.
Note 1: The complete suppression of the weaker signal occurs at the receiver limiter, where it is treated as noise and rejected.
Note 2: When both signals are nearly equal in strength, or are fading independently, the receiver may switch from one to the other. Synonym FM capture effect.
Source: from Federal Standard 1037C and from MIL-STD-188