Sony Tektronix WFM 1125, User Manual

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Reference
3-2
WFM 1125 Option 0A/0B/0C/0D User Manual
Shifted null point
Figure 3-2: Bowtie waveform showing a timing error in CH 3
Although you can use Waveform or Lightning displays to determine channel
timing with most test signals, the Bowtie method provides better resolution of
channel timing and is the easiest to use when the Bowtie test signal is available.
The bowtie measurement also provides a method to determine whether the
relative channel gain is correct. If the gains are not equal, the center null point
will not be a complete null. Figure 3–3 shows a Bowtie display with an incom-
plete null in the right waveform. If the gain error is in CH 1, neither waveform
has a complete null. If CH 2 gain is off, the left waveform will not null
completely, but the right one will. If the gain is off for CH 3, as in Figure 3–3,
the left waveform will be normal and the right one will not reach a complete null.
Incomplete null
Figure 3-3: Bowtie waveform showing gain error in CH 3
Relative Gain Check