The KH43101 pulse limiter is designed to prevent the input of the spectrum analyzer or receiver from being damaged by large transient shocks. When connecting the artificial power network for EMI testing, plugging and unplugging the 220V AC power supply can easily cause the input mixer of the receiver to burn out, and the limiter greatly attenuates the impact from the 220V, 50HZ current and its harmonics, avoiding damage to the mixer to protect the receiver or spectrum analyzer.