1730–Series Checks and Adjustments
5–19
j. CHECK – that the amplitude of the color bar is within 0.95 to 1.05 V
from sync tip to the 100% peak white bar, as displayed on the test
oscilloscope. Turn OFF the 1730–Series LINE SELECT.
k. Disconnect all signal cables from the 1730–Series Waveform Monitor.
12. Check DC Restorer Operation
REQUIREMENT – Attenuation of 60 Hz input signal 20% or less. Blanking
level shift with APL change, less than 1 IRE (7 mV). Blanking level shift with
presence or absence of burst, less than 1 IRE (7 mV).
a. Connect a modulated 5–step linearity signal (with AC Bounce on) to the
CH–B INPUT, and teminate in 75Ω.. Display the signal with the 2H
SWEEP. Turn ON FAST DC REST. Position the blanking level of the
signal to the 0 IRE (0 V) line.
b. CHECK – that the blanking level does not move when the VARIABLE
gain is rotated.
c. CHECK – that the blanking level moves when the DC REST is turned
off. Leave DC REST OFF. Turn off variable gain.
d. Connect the black burst signal to the EXT REF and terminate the
remaining side of the loop–through input.
e. Connect the function generator output through a X10 (75W) Attenuator
to the CH–A INPUT.
f. Select CH–A and EXT REF.
g. Set the function generator frequency to a 60 Hz (50 Hz PAL) sine wave.
Set the amplitude for a 100 IRE (700 mV PAL) 1730–Series display.
h. Turn ON SLOW DC REST.
i. CHECK – that the display amplitude is 80 IRE (560 mV PAL) or
greater.
j. Turn ON FAST DC REST.
k. CHECK – that the display amplitude is 10 IRE (70 mV PAL) or less.
l. Remove the function generator output and replace it with the linearity
signal and terminate the remaining side of the loop–through input.
m. Select 2LINE SWEEP.
n. Turn ON SLOW DC REST.
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