Synthesizer Test Tray A3, Trouble Isolation Chart

TM 11-6625-847-12

Step

Control setting and

Performance standard and

No.

Operation of test

operation of equipment

reference

equipment

Connect AN/URM-145 to

Set tray A3 MC SYNTH OUT-

Observe that output increases as

tray A3 MC SYNTH

PUT AMPL switch to ON, and

adjustment is made clockwise

OUTPUT MC SYNTH

adjust MC SYNTH OUTPUT

(para 4-21, item No. 7).

connector.

VOLT ADJ control from fully

Caution: Adjust AN/

counterclockwise to fully clock-

URM-145 to scale above

wise. Return MC SYNTH

1 volt, and readjust ac-

OUTPUT VOLT ADJ control as/

cordingly to avoid damage

to midrange.

to instrument.

Disconnect AN/URM-145.

Reset all switches and controls

Test set and tray A3 POWER

to settings listed in paragraphs

indicators extinguish

3-10 and 3-13.

Remove RT-62/GRC

Remove tray A3 from test set

modules (1A2, 1A3, 1A4,

and return to case 2.

1A8, and 1A9) from

tray A3 and return

them to proper storage

place.

4-21.

Synthesizer Test Tray A3, Trouble Isolation Chart

Item

No.

Trouble symptom

Probable trouble

Checks and corrective measure

POWER indicator lamp

a. Defective external 27-volt de

a. Higher category repair re-

will not illuminate.

power supply.

quired.

b. Improper seating of input

b. Tighten power connector.

power connector.

c. Defective fuse ----------------------------------

c. Replace fuse (para 4-26a).

d. Defective lamp----------------------------------

d. Replace indicator lamp (para

4-26b).

e. Defective POWER switch -------------------

e. Higher category repair re-

quired.

Tray A3 POWER indicator

a. Improper seating of input

a. Tighten power connector.

lamp will not illuminate.

power connector.

b. Defective test set fuse ------------------------

b. Replace fuse (para 4-26a).

c. Defective indicator lamp ----------------------

c. Replace indicator lamp (para

4-26b).

When test set MC FREQ

a. Improper seating of input

a. Tighten power connector.

select switches 10MC and

power connector.

1MC are rotated in 1-mc

b. Defective motor positioner -------------------

b. Higher category repair re-

steps, module coupler

quired.

does not adjust to new

setting.

With AN/PSM-6 con-

a. Improper seating of input

a. Tighten power connector.

nected across POWER

power connector.

INPUTS (ground) test

b. Defective POWER switch -------------------

b. Higher category repair re-

connectors, adjust

quired.

POWER ADJ control

fully counterclockwise

to fully clockwise; volt-

age varies more or less

than limits of 0 to +26

volts dc

With AN/URM-1465 con-

Improper seating of power con-

Tighten power connector.

nected to 10&1KC

nector.

SYNTH OUTPUT 7.1

MC connector, indication

4-14