Triggering System; Check Vertical Chopped Mode; Check Trigger Source Operation - Tektronix 7603 Instruction Manual

Calibration-7603/R7603 Service
20 . Check Vertical Chopped Mode Operation
a . Connect the 10X probe to the external trigger input
of the 7B53A .
b . Connect the probe tip to TP67 (see Fig . 3-4) .
c . Position the trace several divisions above the center
line with the Position control .
d . Set the VERT MODE switch to CHOP .
e . Set the 7B53A for auto, external triggering at a sweep
rate of 0.2 microsecond/division .
f . CHECK-CRT display for chopped waveform display
with duration of the time segment from each channel,
including the blanked portion, between two and three
divisions. Also, check that the unblanked (visible) portion
of the time segment from each channel consists of at least
75% of the duration of the total channel segment .
g . Disconnect the probe and remove all plug-in units .
TRIGGERING SYSTEM
Equipment Required
1 . Mainframe standardizer calibration fixture
3- 1 2
2 . 7B53A plug-in unit
3 . 7A15A plug-in unit
4 . BNC to pin-jack cable
Fig . 3-4 . Location of TP67 on Logic board (shown with power unit
removed) .
Control Settings
Set the controls as given under Preliminary Control
Settings .
21 . Check Trigger Source Operation
a . Install the mainframe standardizer calibration fixture
in the right vertical compartment and the 7A15A in the left
vertical compartment .
b . Install the 7B53A in the horizontal compartment .
c . Set the 7B53A for auto, internal triggering at a sweep
rate of 0 .5 millisecond/division .
d . Set the 7A15A for a deflection factor of 0 .2
volt/division .
e . Connect the 0 .4 V Calibrator pin-jack to the input of
the 7A15A with the BNC to pin-jack cable .
f . Position the Calibrator waveform display in the upper
half of the graticule area with the 7A15A Position control .
g . Set the VERT MODE switch to RIGHT .
h . Set the calibration fixture Test switch to Vert or
Horiz +Step Resp, Rep Rate switch to 250 Hz, and adjust
the Amplitude control for a two-division display . Position
the display in the lower half of the graticule area .
i . Set the VERT MODE switch to ALT .
j . CHECK-CRT display ; both square-wave displays are
stable .
k . Set the TR IG SOURCE switch to LEFT .
I . CHECK-CRT display ; Calibrator display only is
stable .
m . Set the TRIG SOURCE switch to RIGHT .
n . CHECK-CRT display ; calibration fixture display
only is stable .
o . Disconnect the BNC to pin-jack cable and remove the
plug-in units .