Tektronix TDS5054, Руководство пользователя

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Creating and Using Math Waveforms
3- 178
TDS5000 Series User Manual
Overview Control elements and resources To define a spectral math waveform
Set the
magnitude
scale
8. Select the Mag tab.
9. To select the vertical scale factor, click Scale:
H
dB to display magnitude using the log scale,
expressed in dB relative to the reference level
offset.
H
Linear to display magnitude using units equal to the
source units.
H
dBm to set the reference level offset to predefined
values for dBm; see next step.
Tip. You can adjust the scale and position by clicking
the waveform handle and using the multipurpose knobs.
10. To set the reference level, click Reference Level and use
the multipurpose knobs or pop-up keypad to set the
reference level.
Tip. Reference level is the value at the top of the display
screen. It only applies to magnitude waveforms.
Adjusting the reference level positions the waveform
with respect to the top of the display, but does not
change the position of the waveform with respect to its
ground reference.
11. To set the reference level offset, click Reference Level
Offset, and use the multipurpose knobs or pop-up
keypad to set the offset.
Tip. Offset determines where zero dB is in the output
waveform. Changing offset moves the waveform with
respect to its ground reference. When the input is equal
to the offset, it will display as zero dB in the output.