Instructions

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4.5 Level/Limits
4.5.1 Level/Limits > Units/Graticule
Enables the level to be shown in either dBm or in dB microvolts. It also enables the
brightness of the graticule to be controlled.
dBm selects level measurement in dBm (decibels relative to 1mW into 50
Ohms). dBuV selects level measurement in dB micro volts.
Note that the measurement unit applies to both the graticule values and
to the marker level readout.
Graticule creates a pop-up menu enabling the graticule to be dimmed or turned off
completely.
4.5.2 Level/Limits > Reference Level
Enables the reference measurement level to be changed by turning the Attenuator
on or off. The marking of the keys changes depending upon the measurement units
that have been chosen.
0dBm or 107dBuV turns the attenuator On and sets to level at the top of
the graticule to either 0dBm or 107dBuV. -20dBm or 87dBuV turns the
attenuator Off and sets to level at the top of the graticule to either
-20dBm or 87dBuV.
4.5.3 Maximum Signal Levels
Signals that exceed the reference level may result in measurement errors even where the
excess signal is outside of the current span.
The maximum allowable input is +20dBm or +127dBuV of RF power (approximately 2.2 volts
RMS), or 50V DC. Applying a signal above these levels could damage the unit and such
damage would not be covered by the product warranty.
4.5.4 Level/Limits > Scale/Shift
Enables the scaling of the graticule to be changed from 10dB/div (the default) down
to 1dB/div. For scales of 5dB/div or less, it becomes necessary to move the
graticule window up and down to view different areas of the trace. Shift keys are
provided to do this.
Scale brings up a pop-up menu from which 10, 5, 2 or 1dB/div can be selected.
Shift Up/Down moves the graticule window up or down in one division
steps.
4.5.5 Level/Limits > Offset/Tables
Amplitude Offsets and Compensation Tables are only available when Option U01 is
installed.
Clear All turns off any offsets and any compensation tables that were set to on.
Set opens a new control menu with keys as described below.
75 Ohm adds a fixed offset to compensate for signals coming from a 75 Ohm source.
Fixed Offset enables an offset between -50.0 and +50.0dB to be added to the reference level.
Take care not to overload the input.
Comp. Table enables a file to be loaded that compensates for frequency dependent external devices
such as antennae.
Units/
Graticule
dBm
dBuV
Graticule
Ref
Level
0dBm
-20dBm
Scale/
Shift
Scale
Shift
Down
Shift
Down
Offset/
Tables
Clear
All
Set