Remove the 115-volt a-c source from the rotor.
Remove the jumper from between R2 and S3 and connect the voltmeter across stator terminals
S1 and S3.
Reconnect the 115-volt a-c source to R1 and R2.
Carefully rotate the synchro transmitter to obtain minimum voltmeter indication and secure the
clamps loosened in step a without moving the synchro transmitter.
Remove the test connections and replace the original wiring.
When 115-volts AC is connected to the control transformer, it may overheat and cause permanent
damage if left connected over 2 minutes. If the zeroing procedure cannot be accomplished
within that time, use 78-volts AC.
Loosen the clamps holding the control transformer in place sufficiently to permit rotating the
transformer by hand with moderate force. Disconnect the external wiring to the stator terminals.
Connect a jumper between stator terminal S1 and rotor terminal R1.
Connect an a-c voltmeter across stator terminal S3 and rotor terminal R2. Set the voltmeter to
its 0- to 250-volt scale.
Apply 115-volt, 60-cycle a-c power from a local source to control stator terminals S1 and S3.
Carefully rotate the control transformer to obtain minimum voltmeter indication.
Remove the 115-volt a-c power source from the rotor.
Remove the jumper from between terminals R1 and S1 and connect between terminals S1 and