Abstract: The present invention relates to a device for simulating the locating signals of an I L S beacon, said device comprising on the one hand two chains in parallel respectively intended for generating sinusoidal modulation I L S signals, each comprising a digital generator for one of said signals and a digital analog converter provided with an input for controlling the reference amplitude of its output voltage and, on the other hand, an at least partially digital arrangement for producing reference voltages for said inputs for controlling the digital/analog converters. The invention is applicable for testing apparatus on board an aircraft.