Operating instructions
LOCAL OPERATION
3-28 46882-311D
To observe the power level profile of an RF signal during a level transition, the signal is applied
to the RF input of the monitor and the instrument armed to trigger when a specific RF level is
passed through.
The instrument then displays an RF Power Level vs Time graph, showing the transition.
Bandwidth
The IF filter selected on the Tx TEST screen remains selected when the
TRANSIENT ANALYSIS
function is selected.
Ref level
The graticule of the transient analysis screen is calibrated in 10 dB/division vertically with the top
of the display as the reference level.
To set the reference level, press the [Ref Level] key to highlight the
Ref Level legend. The
required reference level can then be set, either by entering a new value using the data entry keys,
or by adjusting the variable control. The reference level should be set so that the expected
maximum and minimum levels will be visible on the display.
The reference level setting is common with the SPEC ANA mode reference level; a value set
on one, will be found set on the other, when next accessed.
Marker
A variable marker can be displayed, indicated by a fine dotted vertical line, with a read-out of the
marker values displayed at the bottom of the screen. The marker reading provides two values.
The absolute RF power level at the marker position. (Not the level relative to the
Ref
Level
).
A time difference of the position of the marker relative to the trigger point.
If the marker, the
Mkr legend and the relevant readings are not displayed, press the [Marker] key.
They will appear at the bottom of the screen with the
Mkr legend highlighted. The position of the
marker along the time axis of the display can be adjusted using the variable control.
When the marker is displayed and the
Mkr legend highlighted, pressing either the
[Ref Level] key or the [Trig Level] key will highlight the appropriate legend and
transfer the variable control operation from the marker to the highlighted function.
When the marker is displayed and the
Mkr legend highlighted, pressing the [Marker] key
will remove the marker and its readings from the display.
When the marker is displayed but the
Mkr legend is not highlighted, pressing the
[Marker] key will transfer the variable control operation to the marker, and highlight
the
Mkr legend.
Trigger level
The transient capture operation is started by the signal level passing through the set Trigger
Level. The set Trigger Level is relative to the Ref Level (top of display). This is set by pressing
the [Trig Level] key to highlight the Trigger Level legend, then either entering a new value using
the data input keys or by using the variable control. The Trigger Level can be set to any point
within the dynamic range of the current display.
Positive or negative triggering
The transient capture operation can be initiated by either a rising or falling signal. Repeated
presses of the [+/- Trig] key alternates the selection. The state of the current setting is shown as
either +ve edge or -ve edge.
Pre-trigger display
The user can select the proportion of the display given to pre-trigger activity. Repeated presses of
the [Pre Trig] key will step through
0 %
,
25 %
,
50 %
,
75 %
and
100 %
values.
0 %
will cause
the display to commence (on the left of the screen) at the time of trigger,
50 %
will place the