LOC DDM performance test failure.

TM 11-6625-2976-40

2-7. TROUBLESHOOTING TABLE. (CONT)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Check circuit card assembly A6 alinement.

Step 3.

Adjust appropriate (LOC or GS) section of circuit card assembly A6

(para 2-9 or 2-10). If unable to adjust, or if test set fails perfor-

mance test after adjustment, replace circuit card assembly A6.

7. LOC DDM performance test failure.

Check setting of A6R30 (FO-4).

Step 1.

Connect voltmeter to A6J2. Adjust A6R30 for minimum indication on

If performance test indicates fault still exists, follow troubleshooting procedures

Step 2.

under MALFUNCTION item 6.

8. Glide slope DDM performance test failure.

Step 1.

Check setting of A6R37 (FO-4).

Connect voltmeter to A6J1. Adjust A6R37 for minimum indication on

Step 2.

If performance test indicates fault still exists, follow troubleshooting procedures

under MALFUNCTION item 6.

9. Marker beacon performance test failure.

Step 1.

Check setting ofA6R110 (FO-4).

Connect modulation analyzer, INPUT to test set and modulation analyzer

OUTPUT to frequency counter. Press and hold yellow (1300 Hz) push-

button, while adjusting A6R110 until frequency counter display is as

close as possible to 1300 Hz.

Step 2.

Check setting ofA6R119 (FO-4).

With equipment connected as indicated in step 1 and yellow pushbutton

depressed, adjust A6R119 until modulation analyzer indicates 95/0

amplitude modulation.

If necessary, repeat procedure with other MKR BCN pushbutton

depressed.

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