Tektronix 784A Graphics Tablet User Manual


 
Performance Tests
4–66
TDS 684A, TDS 744A, & TDS 784A Service Manual
g. Press the main-menu Bandwidth.
h. Select 250 MHz from the side menu.
i. Press the main-menu Fine Scale.
j. Use the keypad to set the fine scale to 282mV (press 282, SHIFT, m,
then ENTER).
k. Press HORIZONTAL MENU.
l. Press the main-menu Horiz Scale.
m. Use the keypad to set the horizontal scale to 200 ns (press 200, SHIFT,
n, then ENTER).
3. Check Jitter vs. Signal Amplitude
a. Set up equipment for Jitter Test. See Figure 4–25.
H Connect one of the rear panel composite outputs marked COMPST
on the TSG121 through a 75 W cable and a 75 W terminator to the
CH1 input of the TDS.
H Press the 100% FIELD control (the fourth TSG121 front-panel
button from the left) of the PAL signal source.
PAL Signal
Source
Digitizing Oscilloscope
75 W Cable
75 W
Terminator
COMPST
Figure 4–25: Jitter Test Hookup
b. CHECK that the oscilloscope lights up its front panel TRIG’D LED and
it displays the waveform on screen. See Figure 4–26.