The 3581A Wave Analyzer separates and measures the amplitude and frequency of spectral components. Features 5-digit digital readout of tuned frequency and an analog meter which provides two scales for linear voltage readings and two log scales. Frequency range is from 15Hz to 50kHz and accuracy of ?3% and a resolution on 1Hz. The instrument has a linear amplitude range of 30 V to 100 nV full scale and a LOG range from +30 dBm or dBV to -150 dBm or dBV. Other features include a sweep error light, external triggering, and restored output, X-Y recorder output, and penlift output.