Section II. CALIBRATION PROCEDURES AND DEPOT INSPECTION STANDARDS

TM 11-6625-924-14

Section II. CALIBRATION PROCEDURES AND DEPOT INSPECTION STANDARDS

6-7. Test Equipment Required for Calibra-

6-10. Synchro Transmitter Control Adjust-

ment

tion

Adjust each synchro transmitter control to zero, at the

a. Test Set, meter TS-682A/GSM-l.

electrical zero of transmitted synchro B1, by perform-

b. 1,000-ohm resistor, 0.1 percent.

ing the following

c. 10 K-ohm resistor, 0.1 percent.

a. Set the ON-OFF switch (fig. FO-l) to OFF.

6-8. Meter Calibration

b. Connect the alligator clips at the end of the power

a. Place the BRIDGE SEL switch in the FLAG RES

cable to the power source.

position.

c. Connect a jumper lead from the blue wire of the

b. Connect the TS-682A/GSM-l across test jacks

rotor to the black wire of the stator of the synchro

TJ3 and TJ4 located under the top cover.

transmitted control.

c. Apply +50 microampere from the TS-

d. Set the multimeter up for operation on the 3-volt

682A/GSM-l.

ac range.

NOTE

e. Connect the COMMON lead of the multimeter to

If the readings in d and e below are not ob-

the synchro transmitter control black stator wire and

tained, the meter must be replaced.

the AC multimeter lead to the yellow synchro

d. Press the MTR CAL switch located under the top

transmitter control wire.

panel. The test panel meter should indicate +50

f. Set the POINTER NO. l-NO. 2-B306 control to

microampere 2 percent.

NO. 1.

e. Repeat c and d above except apply 30 and 20

g. Set the synchro transmitter control to 0.

microampere from the TS-682A/GSM-l. Meter indica-

h. Turn on the power source and set the ON-OFF

tion should be 30 and 20 microampere respectively2

switch on the test panel to ON.

percent of full scale.

i. Using the vernier knob on the synchro transmitter

f. Place BRIDGE SEL switch to FLAG CUR posi-

control, position the transmitter synchro control for a

tion.

minimum indication on the multimeter (approximately

g. A p p l y + 5 0 0 m i c r o a m p e r e s f r o m t h e

10 millivolts). Set the multimeter to the l-volt range to

TS-682A/GSM-l.

accurately check the minimum indication.

h. Press MTR CAL switch; test panel meter should

j. If the minimum indication is a 0 on the synchro

indicate +500 microampere 2 percent (scale read-

transmitter control, the control is correctly adjusted. If

ing X10). If the proper current cannot be obtained, ad-

the minimum indication is not at O, perform the follow-

just variable resistor R?, located under the top cover.

ing

i. A p p l y - 5 0 0 m i c r o a m p e r e f r o m t h e

(1) Set the synchro transmitter control to 0.

TS-682A/GSM-l.

(2) Open the cover of the test panel (fig. FO-2) and

j. Press MTR CAL switch; test panel meter should

loosen the clamps holding synchro transmitter control

indicate -500 microampere 2 percent (scale reading

housing (not shown).

Xl0).

(3) Holding the synchro transmitter control at O,

k. Disconnect the TS-682A/GSM-l.

turn synchro transmitter control housing until a

6-9. Bridge Calibration

minimum indication is obtained on the multimeter.

NOTE

(4) Tighten the clamps holding the synchro

If the readings in this procedure cannot be ob-

transmitter control housing.

tained, troubleshooting is required.

k. Repeat the procedures in i above to check the ad-

a. Rotate BRIDGE SEL switch to FLAG RES posi-

justment. If the minimum indication on the multimeter

tion and energize test panel.

is still not at 0 on the synchro transmitter control,

b. Connect the 1,000-ohm resistor across test jacks

check to be sure the control is tight on the shaft of the

TJ1 and TJ2 located under the top panel.

synchro transmitter control. Readjust the synchro

c. Press the PRESS to READ switch.

transmitter control if required (j above).

d. Rotate the OHMS control for a null on the meter;

l. Set the test panel ON-OFF switch to OFF and turn

the OHMS dial should indicate 100 1 percent.

off the power source.

e. Replace the 1,000-ohm resistor with the 10 K-ohm

m. Disconnect the multimeter and jumper lead from

resistor.

the synchro transmitter control.

f. Rotate BRIDGE SEL switch to the ANNU RES

position.

6-11. Depot Inspection Standard

g. Press the PRESS TO READ switch.

The depot inspection standard consists of performing

h. Rotate the OHMS control for a null on the meter;

the synchro transmitter tests and test panel resistance

the OHMS dial should indicate 100 1 percent.

measurements (para 6-3, 6-4, and 6-5).

6-3