Iwatsu DS-8814, Operation Manual

Page: 123 / 141

F-10
To appropriately perform a FFT, a window suitable for the data to be measured must be
selected.
(4) While the Display menu is being displayed, the
FFT menu will be displayed if the FUNCTION
knob is turned counter clockwise.
From the F Window menu, select a window
function (Hanning, Flat Top, Rectangular).
For the analysis of a repeating waveform, use
Hanning or Flat Top. Here, Hanning, which is
suitable for frequency analysis, is selected.
(Refer to the previous page and page F-18.)
To verify frequency and/or dBm values, use cursor measurement.
(5) Press the
∆
V/
∆
t/
∆
V&
∆
t/V at t/OFF button,
and select dBm at f.
Turn the FUNCTION knob and move the
cursor to the portion desired to be measured.
The frequency and dBm value at the point of
intersection with the cursor are displayed.
To verify details of the FFT waveform, adjust the OFFSET and DELAY knobs to move
the portion to be enlarged to the screen center. Then, adjust the VOLTS/DIV and
TIME/DIV knobs to enlarge or reduce the vertical or horizontal directions (based on the
screen center).