HP 8590 E-Series User Manual page 253

integrates the power of the displayed spectrum and puts markers at the
OCCUPIED
frequencies containing a selected percent of the power. The measurement
BANDWDTH
defaults to 99% of the occupied bandwidth power. The power-bandwidth
routine first computes the combined power of all signal responses contained
in the trace. For 99% occupied power bandwidth, it then puts markers at
the frequencies at which 0.5% of the power lies to the right of the right
marker and to the left of the left marker. Thus 99% of the power lies between
the markers. The difference of the marker frequencies is the 99% power
bandwidth and is the value displayed.
The OCC BW % POWER softkey can be used to change the measured power
value from 1% to 99.99% of the total displayed power. The occupied
bandwidth function also indicates the value of the measured power in the
occupied bandwidth, and the difference between the spectrum analyzer
center frequency and the center frequency of the occupied bandwidth. The
measurement can be made on a single sweep or to continuously update at the
end of each sweep. The center frequency, reference level, and channel spacing
must be set by the user. Press PARAM AUTO MAN so that AUTO is underlined
and other spectrum analyzer settings will be set automatically set to make
a valid measurement. Set PARAM AUTO MAN to (MAN) to manually control
all settings. The measurement function stops and the spectrum analyzer is
returned to its prior state when other functions are activated.
Front-Panel Key Access: (MEAS/USER)
WINDOWS (ON) HP 85913, HP 85933, HP 8594E, HP 85953, or HP 8596E only.
activates the windows display mode and accesses the menu of window zone
functions. The windows display function splits the screen into two separate
displays. Only one of these displays is active at a time. The currently active
window will have a solid line around the graticule rather than a broken
line. The WINDOWS (NEXT) key will switch the active display between the
upper and lower windows. The instrument state of the active window can
be changed without affecting the state of the inactive window. The complete
annotation is not displayed for each window because of space limitations.
When the windows display mode is first turned on, the top window will
contain an inactive copy of the previous full display. The lower window will
be active and will display a subset of the frequency span of the upper window.
The displayed span, or zone, of the lower window will be indicated on the
upper window by two vertical lines called zone markers. The zone can be
moved and changed using the zone keys which are accessed by pressing the
WINDOWS loN) key. Changing the span or center frequency of the lower
window will change the corresponding zone markers on the upper window.
Most functions can be used from within the windows display mode. Some
functions, like editing limit lines and showing the options, require a full-sized
display. They will temporarily exit the windows display format. When the
function is finished the instrument will return to a windows display. Other
functions will permanently exit the windows display and it will be necessary to
restart the windows display mode by pressing WINDOWS m (see Table 7-9).
Limit lines can be displayed and tested within the windows display mode.
Viewing and testing must be turned on independently in each window. The
current limit lines will be common to both windows.