Tektronix P6042 PROBE, Instruction Manual

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Calibration —Type P6042
Fig. 6-4. Test setup for step 4.
d. Vary the autotransformer voltage from 104 to 126 volts
(208 to 252 volts) and check for no trace shift. Return to 115
volts (230 volts).
3. Adjust —16 Volts (R1 80) Check
Regulation
a. Connect the 1x probe to the —16 volt test point.
Switch Vc Range to —11.
b. Adjust R180 to position the trace on the center graticule
line.
c. Vary the autotransformer voltage form 104 to 126 volts
(208 to 252 volts) and check for no trace shift. Return to 115
volts (230 volts).
d. Disconnect the probe from the —16 volt test point and
remove the differential comparator plug-in unit from the
storage oscilloscope.
4. Adjust Ripple Null (R1 57)
a. Place the selectable bandwidth plug-in unit in the
storage oscilloscope and set the controls as follows:
Volts/cm 500 µV
Low Freq 3 dB Point DC
High Freq 3 dB Point 300 Hz
DC Offset
Off
4- Input Coupling AC
— Input Coupling Gnd
Position trace centered
Set the storage oscilloscope Time/cm to 5 ms.
b. Connect the 1x probe from the 4- Input to the +16
volt test point. See Fig. 6-4.
c. Adjust R157 for minimum ripple. Fig. 6-5 shows a
typical ripple display at 500 µV/cm.
d. Check ripple for ≤2 mV peak to peak (≤ 4 cm at 500
µV/cm).
e. Connect the 1 X probe to the —16 volt test point and
check ripple for <2 mV peak to peak.
f. Remove the probe from the test point.
5. Adjust Attenuator Balance (R84)
a. Remove the connection from J80, on the amplifier cir­
cuit board. See Fig. 6-3 for location of J80.
b. Change Time/cm to 50 µs, and switch input coupling
to Gnd. Position the trace on the center graticule line and
switch input to DC.
6-6