HP 54600A - Reducing Waveform Noise

Figure 22
3 dB down point
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Operating Your Oscilloscope
To reduce tU ra1do• 1olse 01 a tlgtal
To reduce the random noise on a signal
If the signal you are applying to the oscilloscope is noisy (figure 24),
you can set up the oscilloscope to reduce the noise on the waveform
(figure 25). First, you stabilize the displayed waveform by removing the
noise from the trigger path. Second, you reduce the noise on the
displayed waveform.
1 Connect a signal to the oscilloscope and obtain a stable display.
2 Remove
the noise from the trigger path by turning on either
high frequency reject or noise reject.
High frequency reject (HF reject) adds a low pass filter with the 3 dB
point at 50 kHz (see figure 22). You use HF reject to remove high
frequency noise such as AM or FM broadcast stations from the trigger
path.
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Pass
Band
HF reject
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