The Hewlett Packard 333A Distortion Analyzer measures total
distortion down to 0.1% between 5 Hz and 600 kHz; harmonics up to 3 MHz.
Measures noise as low as -50 V, voltage from -300 V to 300 V full scale.
Automatic nulling mode and high-pass filter: 3 dB point at 400 Hz with 18 dB
per octave roll off; 60 Hz rejection: 40 dB.