Note: If the null cannot be obtained without rotating the resolver more than 45" in either direction, check the
mechanical alinement of AZ RSVR B1302 to AZIMUTH counter M1301.
g. Tighten the four resolver mounting screws.
h. After obtaining the null point, rotate the AZIMUTH handwheel to further reduce the null. The null should not exceed
100 millivolts peak-to-peak, with an AZIMUTH counter reading of 1,600 mils + one-fourth mil.
i. If the counter does not read 1,600 mils + one-fourth mil, repeat the step in e, f, g, and h above.
Note: Use only the 400-hertz component of the waveform when observing the null.
7-13. AZIMUTH RESOLVER AMPLIFIER ALINEMENT
a. With the ELEVATION, RANGE, and AZIMUTH handwheels, set the ELEVATION counter to 0, the RANGE
counter to 14, 000 meters, and the AZIMUTH counter to 1, 600 mils.
b. Set the following switches to CAL:
(1) X-Y-RHO switch S803.
(2) AZ RSVR switch S1603.
c. Connect the oscilloscope input to X IN TP803 and GRD TP813.
d. Loosen the locknuts on R1132 and R1151.
e. Alternately adjust R1132 and R1151 until a null of less than 25 millivolts peak-to-peak is observed on the
f, Tighten the locknuts on R11 32 and R1151 and recheck the null.
g. Return switches S1603 and S803 to the OPR position.
7-14. X AND Y COUNTERS ALINEMENT
Check to see that the zero readings on the X and Y digital counters are properly oriented with the AZIMUTH and
ELEVATION digital counters; reset X and Y counters if they are incorrect. Set the MAP SCALE switch to the 1:25K
position, the ELEVATION counter to 0, the AZIMUTH counter to 800 mils, and the RANGE counter to 18, 000 meters.
Check to see that both the X and Y counters read PLUS 12,728 meters + 140 meters; if not, adjust the counters as follows:
a. Set the ELEVATION counter to 0, the MAP SCALE switch to the 1:25K position, and the RANGE counter to 14,
b. Set the AZIMUTH counter to 0. Loosen the locknut and adjust the Y + CAL (R1552) control to PLUS 14, 000
meters on the Y counter; tighten the locknut.
c. Set the AZIMUTH counter to 3, 200 mils. Loosen the locknut and adjust the Y - CAL (R1554) control for MINUS
14,000 meters on the Y counter; tighten the locknut.