TM 11-5840-217-34-1
e. Place X-Y-RHO switch S803 to the CAL position.
f. Connect a jumper across RHO IN TP8II and GRD TP813.
g. Loosen the locknut of RHO BAL pot R977 and adjust for a null of not more than 7 VAC peak-to-peak.
h. Lock the pot and recheck the null.
i. Return S803 to the OPR position; remove the oscilloscope leads and jumper.
7-4. X SERVOAMPLIFIER GAIN AND BALANCE ADJUSTMENTS
a. Connect the oscilloscope to X MOTOR TP804 and GRD TP813.
b. Loosen the locknut of X GAIN pot R833 and turn R833 to its maximum cw position.
c. Turn pot R833 ccw until the X counter oscillations stop. Do not adjust beyond this point.
d. Rotate the RANGE and AZIMUTH handwheels throughout their ranges, stopping each handwheel several times to
observe for signs of oscillations on the oscilloscope or X counter. (If the plotting board is used, declutch the azimuth
coupling. ) If oscillations occur at any range or azimuth, reduce the gain slightly and recheck entire range of controls. Lock
pot R833 in position.
e. Set the X-Y-RHO switch S803 to the CAL position.
f. Connect a jumper across X IN TP803 and GRD TP813.
j. Loosen the locknut of X BAL pot R852 and adjust for a null of less than 7 VAC peak-to-peak.
h. Lock the pot and recheck the null.
i. Return S803 to the OPR position; remove the oscilloscope leads and jumper.
7-5. Y SERVOAMPLIFIER GAIN AND BALANCE ADJUSTMENTS
a. Connect the oscilloscope to Y MOTOR TP810 and GRD TP813.
b. Loosen the locknut of Y GAIN pot R918 and turn R918 to its maximum cw position.
c. Turn pot R918 ccw until the Y counter oscillations stop. Do not adjust beyond this point.
d. Rotate the RANGE and AZIMUTH handwheels throughout their ranges, stopping each handwheel several times to
observe for signs of oscillations on the oscilloscope or Y counter. (If the plotting board is used, declutch the azimuth
coupling. ) If oscillations occur at any range or azimuth, reduce the gain slightly and recheck entire range of controls. Lock
pot R918 in position.
e. Place the X-Y-RHO switch in the CAL position.
f. Connect a jumper across Y IN TP809 and GRD TP813.
g. Loosen the locknut of Y BAL pot R936 and adjust R936 for a null of less than 7 VAC peak-to-peak.
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