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4.5.4 Amplitude Offset and Compensation Tables (when fitted)
enables the amplitude scaling to be offset to match external attenuation or gain, or
to add frequency dependent amplitude compensation tables to match transducers or
antennae. These functions are only available when the upgrade option U01 is fitted
- see section 6. Creates a set of bottom-row function keys as follows:
cancels any offset or compensations that have been set and returns the amplitude
scaling to normal.
opens a control menu that enables compensation for a 75 Ohm source impedance,
a fixed attenuation or gain, or a frequency dependent compensation table to be
used. The functions can be used individually or together.
The three keys on the upper line select which function
is to be controlled.
For 75 Ohm source, the options are only on or off.
For Fixed Offset, the Set Offset key creates a
dialogue box by which an offset can be set between
-50.0dB and +50.0dB. The set figure is added to the
displayed reference level and to the graticule values
and marker readout.
For Compensation Table, the Select Table key opens a file list of stored compensation tables
that can be loaded. See section 7.5.2 for a full explanation.
Whenever offsets or compensations are active, a warning message is displayed at the top right
of the graticule. See section 7.5.1 for safety warnings on the use of these function.
4.5.5 Amplitude Limits (when fitted)
sets one or two horizontal lines or a complex patterns that can be compared with the
sweep. This function is only available when the upgrade option U01 is fitted - see
section 6. Creates a set of bottom-row function keys as follows:
creates a control screen that enables the selection of lines and patterns, or allows
existing ones to be turned on or off. When Set Line is pressed, the value can be
entered numerically in dBm or dBuV. When Select Pattern is pressed, a Recall File
screen is opened enabling a pattern to be loaded from a file. See section 7.6.1.
creates a pop-up menu that selects the criteria upon which a limit condition is
created. The options are None, Above, Below, Outside or Inside.
creates a pop-up menu that selects an action that will be performed when the limit
condition occurs. The options are None, Beep, Pulse Out, Beep + Pulse Out or
Message (Pass/Fail).
Note that other actions (sweep triggering or log file entry) can also be created from the limits
condition. Further information on the Limits function is given in section 7.6.
creates a control screen from which a limit can be offset from its initial values. This
is particularly useful for limit patterns which would otherwise have to be recreated.
allows a limit pattern, once loaded, to be fixed relative to the screen enabling it to be
used for any centre frequency rather than just the one for which it was created.
Offset/
Tables
Clear
All
Set
Limits
Limit
Conditio
n
Limit
Action
Set
Limits
Limit
Condition
Limit
Action
Limit
Offset
Limit
Fix/Unfix