The HP Agilent 11729B Carrier Noise Test Set, combined with an HP 8662A synthesized signal generator and a baseband spectrum analyzer, form a complete broadband measurement system for phase noise and AM noise testing of microwave oscillators, 5 MHz to 18 GHz. With one versatile measurement system, direct AM noise measurements and two methods of phase noise measurements can be made, at offsets from the carrier of < 1 Hz to 10 MHz. These three operating modes allow a wide variety of sources, from low noise stabilized sources to free-running sources with high drift to be measured.