The -hp- Model 3561A is a single channel Fast Fourier Transform (FFT) signal analyzer covering the frequency range to 100 kHz. The -hp-3561A measurement capabilities include magnitude, phase, and time displays in a narrow band, 1 / 3 oc-tave, or full octave format. Narrow band data can be captured and stored in the time buffer for processing with alternate setups without acquiring new data. Resolution in the narrow band mode is 250 Hz for a full 100 kHz display span and 25.6 pHz for the 0.01 Hz display span. The -hp-3561A measures input signals from +27 dBV (22.39 Vrms) down to —51 dBV ( + 2.82 mVrms). The 80 dB dynamic range of the -hp-3561A allows measurement of signals where the signal of interest exists in the presence of large unwanted signals.