Magnify
The magnify softkey allows you to zoom in on a portion of the FFT record.
Use off to view the entire FFT spectrum, and use on to view a portion of the
spectrum.
The magnify softkey affects which two keys are displayed below it. When
magnify is off, the Span and Resolution softkeys are displayed. When
Magnify is on, the Magnify span and Center freq softkeys are displayed. The
Magnify span and Center freq softkeys use software expansion to rescale the
FFT.
Span
The Span softkey sets the maximum frequency of the FFT function. Span is
the sample frequency divided by two (Nyquist frequency). Changing the
span setting also changes the time base settings. You may notice that the
current sample rate is displayed below the span frequency selection. In the
equivalent-time mode, the effective sample rate is displayed. It is equal to
one divided by the time between points, and this number can be much larger
than the oscilloscope’s maximum sample rate.
You can only change the span for channel operands in the real-time
acquisition mode.
Because the keypad does not have keys for entering kHz or MHz, use the
enter exponent key (Eex). For example, to set the span frequency to 125
kHz, press the following keys: 1, 2, 5, Eex, 3, Enter.
Resolution
The Resolution softkey sets the frequency resolution of the FFT record
(number of points). Resolution is the sample rate divided by the record
length. Because resolution is a function of record length, changing the
resolution changes the record length. You may notice that the number of
points used for the FFT computation is displayed below the resolution
frequency selection.
FFT Menu
FFT Scaling
21–5
Содержание 54710A
Страница 7: ...vi ...
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Страница 16: ...Glossary Index Contents Contents 7 ...
Страница 17: ...Contents 8 ...
Страница 65: ...2 16 ...
Страница 72: ...Interpolation turned off Interpolation turned on Figure 3 2 Figure 3 3 Acquisition Menu Interpolate 3 7 ...
Страница 86: ...4 Applications ...
Страница 96: ...6 Display 6 4 Scale 6 5 Offset 6 6 Input 6 6 Probe 6 7 Calibrate 6 10 Channel Menu ...
Страница 98: ...Channel menu and menu map for the HP 54712A plug in Figure 6 1 Channel Menu 6 3 ...
Страница 110: ...7 Thresholds 7 4 Top Base 7 6 Define time 7 8 Statistics 7 9 Define Measure Menu ...
Страница 112: ...Define measure menu and menu map Figure 7 2 Define Measure Menu 7 3 ...
Страница 143: ...8 22 ...
Страница 144: ...9 Persistence 9 3 Color Grade 9 5 Draw waveform 9 6 Graticule 9 10 Label 9 14 Color 9 17 Display Menu ...
Страница 163: ...9 20 ...
Страница 164: ...10 Messages ...
Страница 170: ...11 Off 11 3 Manual 11 3 Waveform 11 5 Measurement 11 7 Marker Hints 11 8 Histogram 11 8 Marker Menu ...
Страница 178: ...12 Function 12 3 Define Function 12 4 Display 12 7 Math Menu ...
Страница 186: ...13 Measurements ...
Страница 199: ...Waveform definitions used to make voltage measurements Figure 13 10 Measurements Voltage Measurements 13 14 ...
Страница 239: ...Response of a Gaussian Filter Versus Frequency Figure 13 26 Measurements Time interval measurements 13 54 ...
Страница 245: ...13 60 ...
Страница 246: ...14 Setup Memory 14 3 Save 14 3 Recall 14 4 Default Setups 14 4 Setup Menu ...
Страница 261: ...15 10 ...
Страница 274: ...17 Scale 17 3 Position 17 3 Reference 17 4 Windowing 17 5 Time Base Menu ...
Страница 282: ...Trigger menu and menu map Figure 18 1 Trigger Menu 18 3 ...
Страница 319: ...19 18 ...
Страница 322: ...20 Waveform 20 3 Pixel 20 6 Waveform Menu ...
Страница 328: ...21 Display 21 3 Source 21 3 Window 21 3 FFT Scaling 21 4 FFTs and Automatic Measurements 21 8 FFT Basics 21 10 FFT Menu ...
Страница 346: ...Limit test menu and menu map Figure 22 2 Limit Test Menu 22 3 ...
Страница 357: ...22 14 ...
Страница 360: ...Mask menu map Figure 23 1 Mask Menu 23 3 ...
Страница 370: ...Figure 23 3 Figure 23 4 Mask Menu Edit Mask 23 13 ...
Страница 407: ...Index 10 ...
Страница 409: ......