Tektronix WFM 601A, Service Manual

Page: 78 / 368

Performance Verification
4–14
WFM 601A, WFM 601E, & WFM 601M Service Manual
f. Select the following on the 1780/81:
INPUT CH A
FILTER FLAT
REF EXT
RIGHT DISPLAY WFM+CAL
WFM HORIZONTAL TWO LINE
GAIN X1
g. Select the Configure Menu on the 1780/81. Set the FIXED CAL AMPL
to 700, then select page 2 and set the ABS UNITS to mV and set the
CAL to VAR.
h. Position the display so the Peak White and blanking level are visible on
the 1780/81.
i. Adjust the large knob on the 1780/81 until the Peak White and blanking
of the chopped display are matched. Use X5 Gain for better resolution.
j. CHECK – that the CAL read out on the 1780/81 is 693 mV to 707 mV.
k. Move the 75 ohm cable on the waveform monitor Y/G MON OUT
connector to the MON OUT P
b
/B connector.
l. Adjust the large knob on the 1780/81 until the Peak P
b
level and negative
going level of the chopped P
b
display are matched.
m. Adjust the vertical position to place the chopped display on the 0 IRE
(0 mV PAL) line on the 1780/81 R.
n. CHECK – that the CAL read out on the 1780/81 is 693 mV to 707 mV.
o. Move the 75 ohm cable from the P
b
/B MON OUT to the P
r
/R MON
OUT.
p. Adjust the vertical position to place the chopped display on the 0 IRE
(0 mV PAL) line on the 1780/81 R.
q. Adjust the large knob on the 1780/81 until the Peak P
r
level and negative
going level of the chopped P
r
display are matched.
r. CHECK – that the CAL read out on the 1780/81 is 693 mV to 707 mV.
s. Disconnect the cable from the MON OUT P
r
/R.