Why A noise blanker samples the incoming signal in a wide bandwidth, detects short, high-amplitude spikes, and mutes (gates off) the receiver for the few microseconds each spike lasts. That works only if the interference is brief compared to the desired signal, which is the signature of impulse noise like ignition pulses, electric fences, or arcing power line hardware. Because the blanker has nothing to trigger on during continuous noise, it can only help with pulse-type interference.
Watch out Broadband white noise and 60 Hz hum or buzz are continuous, so there is no quiet interval to gate into; those are jobs for DSP noise reduction, a noise-reduction filter, or fixing the noise source, not a blanker.
Blanker = blanks out blips. Pulses only; steady hiss and hum need DSP noise reduction.