TB 9-4931-504-40
(7) Adjust R232 until first dot is on rise of pulse and level with top lead corner of display.
(8) Repeat (1) above for channel 2.
(9) Adjust R330 (fig. 2) for no vertical shift while simultaneously adjusting R331
(fig. 2) back and forth between fully ccw and 90 degree position. Readjust R331 fully ccw.
(10) Repeat technique of (3) and (4) above for CH2, except adjust R344 (fig. 2).
(11) Repeat technique of (5) and (6) above for CH2.
(12) Adjust R331 until first dot is on rise of pulse and level with top lead corner of display.
22. Low Frequency Comparator
a. Performance Check
(1) Set VOLTS/DIV switch to 10 mV and DELAYED SWEEP SEC/DIV and
DELAYING SWEEP switches to 1 S.
(2) Connect oscilloscope calibrator SOURCE/MEASURE CHAN 1 to CH1 and
CH2 INPUTS.
(3) Adjust oscilloscope calibrator square wave output frequency for 100 kHz and
amplitude for 4 divisions of display. If oscilloscope does not display square wave with flat
top and level within 0.2 divisions, perform b below.
(4) Press CH1 and release CH2 pushbuttons.
(5) Repeat technique of (3) above for channel 1.
b. Adjustments. Adjust channel 2, R30 (channel 1, R30) (fig. 2) for optimum square
wave display.
23. Power Supply
NOTE
Do not perform power supply check if all other parameters are
within tolerance.
a. Performance
(1) Connect multimeter to +30 V test point (fig. 1) and chassis ground. Multimeter
will indicate between +29.1 and +30.9 V dc.
(2) Repeat technique of (1) above for test points and multimeter indications listed in
table 5. Multimeter will indicate within limits specified.
Table 5. Power Supply Check
Test instrument
Multimeter indications
test points
(V dc)
Min
Max
+15
+14.55
+15.45
-30
-29.10
-30.90
-15
-14.55
-15.45
-5
-4.85
-5.15
+5
+4.85
+5.15
