HP 8590 E-Series User Manual page 255

lets the user choose between automatically or manually setting the parameters
AUTO MAN
used for the measurement functions under the
Parameters such as span, resolution bandwidth, video bandwidth, center
frequency step size, detector mode, and sweep time are coupled so that they
are automatically updated. With AUTO underlined when channel bandwidth
or channel spacing are changed, the coupled parameters will be updated and
another sweep will be taken and measured. If MAN is underlined the user
must set all of the parameters correctlv.
Front-Panel Key Access: (MEAS/USER) *
PEAK
sets the minimum amplitude variation of signals that the marker can identify
EXCURSM
as a peak. If a value of 10 dB is selected, the marker moves only to peaks that
rise and fall more than 10 dB above the threshold line (or the noise floor of the
display). Pressing Ii%'?'E) or turning on power resets the excursion to 6 dB,
and the threshold to 70 dB below the reference level.
Note
When a peak has a lump on its skirt that is the peak-excursion value above the
threshold, the lump is considered a peak in its own right only if it has a peak
excursion drop on both sides. Two peaks that are so close that only a valley
divides them are not differentiated if the valley is not the peak-excursion value
deep.
When the peak excursion value is less than 6 dB, the marker-peaking functions
may not recognize signals less than 6 dB above the noise floor. To correct
this, when measuring signals near the noise floor, the excursion value can be
reduced even further. To prevent the marker from identifying noise as signals,
reduce the noise floor variance to a value less than the peak-excursion value
by reducing the video bandwidth or by using video averaging.
Front-Panel Key Access:
accesses the same softkeys that are available when
Peak
Menu
See the key description for
new peak search.
Front-Panel Key Access: CMKR-t]
automatically places a marker on the highest amplitude of a trace, displays the
marker's amplitude and frequency. It also accesses the menus of marker peak
functions including the peak table functions.
7-62 Key Descriptions
allows you to use the peak-search functions without initiating a
Power Menu
is pressed.
Peak
Pressing Menu instead of