scope:

The equipment specified herein is a solid state electronic modulator designed to modulate a CW RF carrier at 90 and 150 Hz sinusoidal rates to generate navigational signals for the localizer or glide slope portions of an Instrument Landing System (ILS). The modulator includes provisions for separating the modulated RF signal into a modulated carrier output and a sideband output (suppressed carrier) at the proper levels and phase relationships for distribution to a standard localizer or glide slope antenna system. Provisions are also included for varying the modulation level, amplitude and phase of the output signals to adjust and maintain the navigational system within prescribed performance standards and tolerances.