Tektronix 7B53A, Инструкция по эксплуатации

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7B53A/7B53AN OPTION 5
CALIBRATION PROCEDURE
Optional Test Equipment
067-0601-00 Calibration Fixture (Television Test Signal
Generator)
Plug-In Cards for 067-0601-00 Generator
067-5001-00 System A 405/50
067-5002-00 System M
525/60
067-5003-00 System B 625/50
067-5004-00
System E 819/50
067-5005-00 System F 819/50
067-5006-00
EIA Standard 729/60
067-5007-00 EIA Standard
875/60
067-5008-00
EIA Standard 945/60
067-5009-00 EIA Standard
1029/60
067-5010-00 EIA Standard 1201/60
CHECK/ADJUST PROCEDURE
1. Check TP900 Waveform
a. Connect a composite video signal to the vertical
plug-in unit.
b. Set the 7B53A/7B53AN OPTION 5 controls as
follows:
Main Triggering Amplifier
SLOPE
MODE
COUPLING
SOURCE
MAIN TIME
BASE
AUTO
DC
TV FIELD
NOTE
If the trigger pick-off circuit is overdriven or the
piug-in Vertical Position control is rotated to its fully
clockwise or counterclockwise position, the wave­
form may become distorted. If so, the sync separator
will not function properly unless the display ampli­
tude is 2 major divisions as described in part c of this
step and the Vertical Position control is moved away
from its extreme position.
2. Check TP926 Waveform and Adjust R914
a. Connect the 10X probe to TP926. Set the test
oscilloscope controls to obtain a stable display.
b. Adjust the Clipping Level control R914 by rotating
the control fully clockwise. Then, rotate the control
counterclockwise until one or more negative-going pulses in
a group are displayed on the test oscilloscope during the
vertical sync pulse interval. The exact number of pulses is
dependent on the television standard of the composite
video signal being applied to the vertical plug-in unit. Fig. 1
shows a normal display obtained for the 525/60 television
standard. The pulse amplitude is approximately 4 volts
negative below the H pulses. If R914 is improperly
adjusted, the H rate trigger will not be normal during the
vertical sync pulse interval.
3. Check TP932 Waveform
a. Connect the 10X probe to TP932.
MAG X1
TIME/DIV 2 ms
c. Adjust the vertical deflection factor of the oscillo­
scope to obtain a 2 major division display. Adjust the
7B53A/7B53AN OPTION 5 Main Triggering Amplifier
LEVEL control to obtain a triggered display.
d. Connect a 10X probe from the test oscilloscope to
TP900 on the TV Sync Separator board. Connect a field
drive signal from the signal generator to the test oscillo­
scope Ext Trig Input connector for use as an external
trigger source.
e. Check for a normal video signal display on the test
oscilloscope (same as signal from generator). Amplitude of
the signal will vary with changes of input signal level.
Fig. 1. Normal 525/60 waveform at TP926. Vertical deflection
factor is 2 V/div; time/div is 50 µs.
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