DC to 10 MHz with advanced, optimized time-gated spectrum analysis. For burst or time-varying signal only a selected part of a waveform may need to be analyzed. Time-selective spectrum analysis takes specific portions of the time-domain signal for analysis. Flexible triggering from internal source, external source, HP-IB or band-limited IF. 1.0 Hz to 10 MHz frequency span, resolution b/w 312.5 µHz to 3 MHz. Color CRT, DOS/LIF floppy disk, HP-IB. 89440A extends coverage to 1.8 GHz using the 89430A RF Section. 89441A extends coverage to 2.65 GHz using the 89431A RF Section. The 89410A covers a frequency range of dc to 10 MHz and offers an optional second channel. The second channel makes it possible to measure frequency response or perform vector network analysis, and the built-in math functions facilitate measurement calibration and correction. Two-channel statistical measurements such as cross-correlation and coherence can also be made. The 89410A provides a flexible source for circuit stimulation. Sinewaves, periodic chirps (sinewave sweeps), and pseudo-random noise are available, along with user-definable arbitrary waveforms. The arbitrary waveforms operate on a block of up to 4096 complex points. Any of these signals can be used as a stimulus while spectrum measurements are made elsewhere in the circuit. Source level and dc offset of the pattern are all controllable by the user.