Signal Attenuator

From HFUnderground

A Signal Attenuator is a setting on many shortwave radios, often labeled as a "DX/Local" switch. Many radios cannot handle extremely strong signals, as they are designed to work well with the weak signals that are typical of many distant, or "DX" shortwave stations. Stations that are close, or "local", can overwhelm the radio's circuitry, distorting the audio, and even making the station unlistenable. The signal attenuator circuit reduces the intensity of the signal to a level that the radio can handle.