HP 8590 E-Series User Manual page 352

video filter
A post-detection, low-pass filter that determines the bandwidth of the video amplifier. It is
used to average or smooth a trace. Refer also to video bandwidth.
windows display mode
A display mode of the HP 8590 Series Spectrum Analyzers where the screen area is
split into two separate displays. This allows two different frequency spans to be viewed
simultaneously. The analyzer state of the two displays can be set independently.
zero span
The case in which a spectrum analyzer's local oscillator remains fixed at a given frequency
so that the analyzer becomes a fixed-tuned receiver. In this state, the bandwidth is equal
to the resolution bandwidth. Signal amplitude variations are displayed as a function of
time. To avoid loss of signal information, the resolution bandwidth must be as wide as the
signal bandwidth. To avoid any smoothing, the video bandwidth must be set wider than the
resolution bandwidth.
zoom
A term referring to the process of looking at something more closely. This may require
narrowing the resolution bandwidth or span to view a signal more closely. Or, it may mean
increasing the size of the spectrum analyzer display from a partial screen to the full screen.
Glossary-l 8