TB 11-6625-821-35
front panel rear, behind SIGNAL GENERATOR rf connector. Connection may be made at
either end of the short wires, whichever is most practical.
(2) Connect the equipment, as shown in figure 8, with the hot lead from signal
generator AN/URM-25 connected to the green lead of resolver B1 and the negative lead to
the yellow wire on B1. Connect the hot lead from the oscilloscope to the blue wire on
resolver B1 and the negative lead to the orange wire.
(3) Set the POWER switch of signal generator to ON, and allow 15 minutes for
equipment to warm up and stabilize.
(4) Adjust the output of signal generator to 100 kc at 0.1 volt, unmodulated.
(5) Set the LOOP SIMULATOR needle to E.
(6) Rotate the LOOP SIMULATOR toward N while observing voltmeter indication.
(7) Voltmeter will indicate a null when the LOOP SIMULATOR is set to N.
(8) Rotate the LOOP SIMULATOR 5 degrees clockwise from N. Center the pattern
on oscilloscope.
(9) A 1-to-1 Lissajous pattern will appear on oscilloscope with the top of the pattern
tilted into the upper right-hand quadrant.
(10) If the LOOP SIMULATOR performs properly, disconnect the equipment and
replace the LOOP SIMULATOR. If it does not meet specifications, leave the equipment
connected and proceed with the adjustment procedures.
b. Adjustment Procedure
(1) Set the LOOP SIMULATOR needle to N.
(2) Loosen the three resolver clamps holding resolver B1 to the resolver housing.
(3) Rotate the entire resolver until a null is indicated on voltmeter.
(4) A 360-degree rotation of resolver B1 will produce two nulls 180 degrees from
each other. To determine which is the correct null, perform the following procedure:
(a) As viewed from the rear of the LOOP SIMULATOR, rotate resolver B1
approximately 5 degrees clockwise from the null position.
(b) Disconnect the horizontal lead from oscilloscope and adjust the vertical gain
for a 4-centimeter vertical trace, centered on the vertical axis.
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