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Operating Instructions—7623A/R7623A Operators
DISPLAY FOCUS
8. Adjust the FOCUS adjustment for a sharp, well-defined display over the entire trace length. If a
properly focused display cannot be obtained with the FOCUS adjustment, the internal Astigmatism adjust-
ment must be reset; see the Calibration section of the Service manual.
TRACE ALIGNMENT
9. Position the trace with the left vertical unit position control! so it coincides with the center hori-
zontal line of the graticule. If the trace is not parallel to the center horizontal line of the graticule, see
Trace Rotation adjustment procedure in Calibration section.
10. Connect the 4 V calibration pin-jack to the input of the left vertical unit with a BNC to pin-jack
cable (supplied accessory) and adjust the time-base unit for a stable display.
GRATICULE ILLUMINATION
11. Rotate the GRATICULE ILLUM control throughout its range and notice that the illumination of
the graticule lines increases as the control is turned clockwise (most obvious with tinted filter installed). Set
the control so the graticule lines are illuminated as desired.
VERTICAL DEFLECTION SYSTEM
12. Set both vertical units for a deflection factor of one volt/division. The display amplitude should
be four divisions. Note the exact display amplitude for step 15.
13. Notice that the position control of only the left vertical unit has an effect on the position of the
display. Position the display to the upper half of the graticule.
14. Press the RIGHT button of the VERT MODE switch. Removethe calibrator signal from the left
vertical and connectit to the right vertical. The display amplitude should be four divisions within 0.12 div-
ision. Note the exact display amplitude for the next step.
15. Acorrect display in both steps 12 and 14 indicates that the 7623A Vertical Deflection System and
the vertical plug-in units are calibrated. If the displays noted previously are both outside the given tolerance
in the samedirection (i.e., high or low), the Vertical Gain or 4 Volts calibrator adjustment may need re-
adjustment. Otherwise, check the calibration of the vertical plug-in units.
16. Notice that the position control of only the right vertical unit has an effect on the position of
the display. Position the display to the lower half of the graticule. Set both vertical units for a deflection
factor of two volts/division. Connect the calibrator signal to both vertical units by using a dual input coup-
ler ora BNC T connector.
17. Press the ALT pushbutton of the VERT MODE switch. Notice that two traces are displayed on
the crt. The top trace is produced bythe left vertical unit and the bottom trace is produced by the right
vertical unit. Set the sweep rate to 50 milliseconds/division. Notice that the display alternates between
the left and right vertical units after each sweep. Turn the sweep rate switch throughout its range. Notice
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