HP ESA-L1500A User's And Calibration Manual page 99

Front-Panel Key Reference
Search
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. Key Access:
sets a lower boundary to the active trace. The threshold line "clips"
Pk Threshold
signals that appear below the line when this function is on. The
boundary is defined in amplitude units that correspond to its vertical
position when compared to the reference level. In other words, if the
reference level is -10 dBm, and the threshold is set to 75 dBm, the
threshold will remain 65 dB below the reference level as the reference
level is changed.
The value of the threshold appears in the active-function block and on
the lower- left side of the display. The threshold level does not influence
the trace memory or marker position. The peaks found by the markers
must be at least the peak- excursion value above the threshold level.
The value of the threshold level can be changed using the step keys, the
knob, or the numeric keypad. Pressing any digit, 0 through 9, on the
numeric keypad brings up the selected terminator menu. The threshold
value affects peak searching functions (except for
when the
finds and displays the frequency and amplitude differences between the
Pk-Pk Search
highest and lowest trace points. Pressing
routine similar to pressing the following keys:
Mkr
moves the active marker to the minimum detected amplitude value.
Min Search
Key Access:
changes the start frequency so that it is equal to the frequency of the
Mkr Start
active marker. This moves the active marker to the left edge of the
display. Key Access:
changes the stop frequency so that it is equal to the frequency of the
Mkr Stop
active marker. This moves the active marker to the right edge of the
display. Key Access:
changes the center-frequency step size to match the value of the active
Mkr CF Step
marker. Press
marker delta is active, the step size will be set to the frequency
difference between the markers. Key Access:
sets the start and stop frequencies to the values of the delta markers.
Mkr Span
The start and stop frequencies will not be set if the delta marker is off.
Key Access:
98
function is set to
Pk Threshold
. Key Access:
Min Search, More
Search, More
Search, More
Search
then
Frequency
,
Search More
. Key Access:
On
Pk-Pk Search
Peak Search
,
More
CF Step Auto Man
Search
Search
) even
Peak Search
,
Search More
performs the
, , and
Mkr
to view the step size. If
,
More
Chapter 4