Adjustment Procedures
1780R-Series Service Manual 5–15
Figure 5–7: Adjustment and test point locations on the Waveform HV Supply circuit
board (Assembly 16.)
NOTE. The +5 V supply is the reference supply for the instrument. If it is
adjusted, the entire instrument will need to be recalibrated. Do not adjust the
+5 V supply if it is within listed tolerance.
The +5 V supply affects both the + and –15 V supplies. The +5 V supply can be
set anywhere within its tolerance to ensure that the other supplies are within
specification.
b. Disconnect the DMM (DM501A) leads from the instrument.
c. Select WFM HORIZONTAL-TWO-LINE on the 1780R-Series right
front panel.
d. Adjust Ripple Null (A16R135) for minimum Z-Axis intensity modula-
tion of the color bar display on the Waveform CRT.
3. Set Software Options (see Note)
NOTE. This step is not required unless calibration data becomes lost or invalid.
Some examples of this are: Non-volatile memory is reset, or the MPU board is
replaced.
a. Enter the CONFIGURE menu and go to page 3 of the menu.
b. Touch <VERSION> on the screen, then immediately press the front-pan-
el REFERENCE SET button. The menu screen now provides two
settings: HORIZ POS POT and TC ON VC IN LS (Time Cursors on
Voltage Cursors in Line Select).
c. Select the menu settings that are appropriate for the instrument: