Tektronix TDS 600B Graphics Tablet User Manual


 
Using Features for Advanced Applications
3–196
TDS 500C, TDS 600B, & TDS 700C User Manual
Figure 3–94: FFT Math Waveform in Math1
Once you have displayed an FFT math waveform, use cursors to measure its
frequency amplitude or phase angle.
1. Be sure MORE is selected in the channel selection buttons and that the FFT
math waveform is selected in the More main menu.
2. Press CURSOR Mode (main) Independent (side) Func-
tion (main) H Bars (side).
3. Use the general purpose knob to align the selected cursor (solid line) to the
top (or to any amplitude on the waveform you choose).
4. Press SELECT to select the other cursor. Use the general purpose knob to
align the selected cursor to the bottom (or to any amplitude on the waveform
you choose).
5. Read the amplitude between the two cursors from the D: readout. Read the
amplitude of the selected cursor relative to either 1 V
RMS
(0 dB), ground
(0 volts), or the zero phase level
(0 degrees or 0 radians) from the @:
readout. (The waveform reference indicator at the left side of the graticule
indicates the level where phase is zero for phase FFTs.)
To Take Cursor
Measurements of an FFT