TEST PROCEDURE - TM-11-5820-670-300136

TM 11-5820-670-30

2-21. SQUELCH SWITCH AND FREQUENCY SELECTION TEST. (CONT)

TEST PROCEDURE

1. Set control unit SQUELCH switch under test to CARR.

2. Rotate receiver-transmitter SQ ADJ control fully counterclockwise.

STANDARD. Presence of noise in speaker.

3. If no noise is present, see troubleshooting chart 2-24, item 5.

4. Rotate SQ ADJ fully clockwise.

STANDARD. Absence of noise in speaker.

5. If noise is present in speaker, see troubleshooting chart 2-24, item 5.

6. Set control unit SQUELCH switch under test to DIS.

STANDARD. Presence of noise in speaker.

7. If noise is not present, see troubleshooting chart 2-24, item 6.

8. Rotate SQ ADJ control fully counterclockwise.

STANDARD. Presence of noise in speaker.

9. If noise is not present, see troubleshooting chart 2-24, item 6.

10. Set control unit SQUELCH switch under test fully clockwise (TONE).

STANDARD. Absence of noise in speaker.

11. If noise is present in speaker, see troubleshooting chart 2-24, item 5.

NOTE

Reset SQ ADJ control by placing SQUELCH switch on the control unit to CARR and ro-

tating SQ ADJ clockwise from a fully counterclockwise position to a point just beyond the

point where squelch-break occurs.

12. Set control unit SQUELCH switch under test to DIS.

13. Decrease frequency setting of control unit from 30.95 MHz to 30.00 MHz in 0.05 MHz steps.

STANDARD. The kHz indicator on gearbox assembly should correspond to last two digits of selected

frequency. Antenna coupler simulator should not run.

2-44