Operating instructions

LOCAL OPERATION
3-29
As the Spectrum Analyzer uses the same IF filters, the optimum filtering can be selected by
examining the signal using the Spectrum Analyzer.
Pressing the [Return] key will display the top level Tx TEST mode screen.
If the operating mode of the Service Monitor is changed from Tx TEST mode with the harmonic
analysis function selected, the harmonic analysis screen will be displayed again when Tx TEST
mode is next selected.
RF transient power analysis
This facility is used to capture, display and record changes to power levels of RF signals. The
TRANSIENT ANALYSIS screen, used to control and display this function, is accessed from the
Tx TEST mode by the key sequence [Tx Power], [Trans Analys]. See Fig. 3-7, Power Transient
Analysis screen.
1 Ref Level 5 Display Centre-line
2 Trigger Level 6 Marker Datum
3 Trigger Datum 7 Marker Point
4 Trigger Point 8 Time/Div Adjustment
Fig. 3-7 Power Transient Analysis screen
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 Service Monitor armed to trigger when a specific RF level is
passed through.
The Service Monitor 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.