Tests Performed With Test Panel

TM 11-6625-924-14

3-2. Tests Performed With Test Panel

d. Set amplitude of AN/URM-127 output for 0.5 volt

as indicated on the ME-30A/U.

High potential (HIGH POT) test (para 3-4).

Lighting test (para 3-5).

e. Rotate the AN/URM-127 frequency dial for an in-

phase pattern on the AN/USM-81.

B306 rotor tuning test (para 3-6).

Pointer No. 1 test (para 3-7).

f. Frequency, as indicated by AN/USM-207 should

Pointer No. 2 test (para 3-8).

be 740 Hertz 10.

Heading dial test (para 3-9).

g. Set the ON-OFF switch to ON.

B306 calibration error test (para 3-10).

h. A Rotate the heading dial on the indicator through

B307 calibration error test (para 3-11).

360 degrees by rotating the synchro transmitter No. 2

B308 calibration error test (para 3-12).

control. Adjust the frequency dial on the AN/URM-127

B304 calibration error test (para 3-13).

to keep an inphase pattern on the AN/USM-281.

Flag test (para 3-14).

i. The frequency on the AN/USM-207 should be 740

Annunciator test (para 3-15).

Hertz 10.

j. Disconnect the test equipment from test panel.

3-3. Starting Procedure

3-7. Pointer No. 1 Test

a Set the ON-OFF switch to OFF.

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

a. Set switches on test panel as follows:

panel power cable to the 115 VAC, 400-Hertz power

(1) ADF-VOR-RMI switch to ADF.

source.

(2) POINTER NO. l-NO.2-B306 switch to NO. 1.

c. Connect the indicator to be tested to the test panel

(3) POINTERS 1 & 2-ALL OTHER TESTS switch

test cable.

to POINTERS 1 &2.

d. Place the indicator to be' tested in the indicator

b. Set ADF-VOR switch on indicator to ADF.

mount on top of the test panel.

c. Rotate the synchro transmitter No. 1 control in

e. Turn the power source on.

30-degree increments through 360 degrees.

d. Note error between pointer No. 1 on the indicator

NOTE

and the synchro transmitter No. 1 dial reading. The er-

In the following procedures, all controls, in-

dicators, binding posts, etc. are on test panel

ror should not exceed 1.5 degrees.

unless otherwise stated.

e. Set ADF-VOR-RMI switch to VOR.

f. Set the ADF-VOR switch on the indicator to VOR.

3-4. High Potential Test

g. Rotate the synchro transmitter No. 1 control in

a. Connect Ohmmeter ZM-21 (*)/U between the

60-degree increments through 360 degrees and note

HIGH POT binding posts.

the error between pointer No. 1 on the indicator and

b. Rotate the PIN SELECTOR control through each

the synchro transmitter No. 1 dial for each control posi-

of its positions, starting with its counterclockwise posi-

tion. The error should not exceed 1.5 degrees.

tion. The position numbers on the PIN SELECTOR

h. Operate the ADF-VOR-RMI switch to RMI.

control correspond to the pins being tested on the in-

i. Repeat step g above.

dicator receptacle.

3-8. Pointer No. 2 Test

c. The resistance at each switch position should be

a. Operate POINTER NO. l-NO. 2-B306 switch to

250,000 ohms or greater.

d. Disconnect the ohmmeter.

NO. 2.

b. Perform the steps in paragraph 3-7b through i,

3-5. Lighting Test

except substitute pointer No. 2 for pointer No. 1

a. Connect the 5-vdc power supply to the 5 VDC

wherever referenced.

binding posts. Connect the AN/USM-223 in series with

3-9. Heading Dial Test

one leg of the power supply (2.5 amp range).

a. Set the synchro transmitter No. 2 control to

b. Turn on and adjust the 5 vdc power supply for 5

volts 0.1.

ZERO.

C. The AN/USM-223 should indicate 1.08 amperes

b. Rotate the indicator SYNC knob until zero degree

0.12.

on its heading dial aligns with the major index within

0.5 degree.

d. Turn off and disconnect the 5-vdc power supply

and AN/USM-223.

c. Rotate the heading dial in 60-degree increments

with the synchro transmitter No. 2 control.

3-6. B306 Rotor Tuning Test

d. The error spread between the 60-degree incre-

a. Connect additional equipment (para 1-11) as

ment settings should not exceed 1.25 degrees.

shown in figure FO-3.

3-10. B306 Calibration Error Test

b. Place POINTER NO. l-NO.2-B306 switch at NO.

2 position.

a. Set the POINTER NO. l-NO.2-B306 switch to the

B306 position and the POINTERS 1 & 2-ALL OTHER

c. Connect ME-30A/U across VTVM binding posts.

3-2