SILICON VERSION A5200A SQUELCH AMPLIFIER ALINEMENT, OLD SQUELCH LEVEL.

TM 11-5820-401-34-3/0967-LP-432-3060

5-27. A5200 SQUELCH AMPLIFIER ALINEMENT, OLD SQUELCH LEVEL. (CONT)

9. Adjust AN/URM-103 DEVIATION control for 3-kHz reading on DEVIATION KHZ meter.

10. Adjust AN/URM-127 FREQ RANGE DIAL to vary frequency above and below 7.3 kHz while

observing ME-30(*)/U. Stop at frequency that gives highest possible ME-30(*)/U

reading. At same time, adjust AN/URM-103 DEVIATION control to keep ME-30(*)/U reading

between 2 and 4 vac. If adjustment of DEVIATION control is required, readjust AN/URM-127

frequency for peak ME-30(*)/U reading.

11.Adjust AN/URM-103 DEVIATION control for ME-30(*)/U reading 4 db less than reading

recorded in step 5.

12. Check R-442/VRC CALL light. If light is out, go to step 13. If light is on, go to step 14.

13. CALL LIGHT OUT. Turn R5216 (3) counterclockwise slowly and stop at point where light

just comes on.

14. CALL LIGHT ON. Turn R5216 (3) clockwise until light goes out, then perform step 13.

OLD SQUELCH Final Test

15. Adjust AN/URM-103 DEVIATION control for 8 kHz reading on DEVIATION KHZ meter.

16. Set AN/USM-127 FREQ RANGE MULTIPLIER to x10.

17. Set AN/USM-127 FREQ RANGE DIAL to 35 (350 Hz). R-442/VRC CALL light should be on.

NOTE

CALL light must stay on through range of 350 to 3500 Hz.

18.

Rotate FREQ RANGE DIAL fully clockwise to 2000 Hz. CALL light should stay on.

19.

Rotate FREQ RANGE DIAL fully counterclockwise.

20.

Set FREQ RANGE MULTIPLIER to x100.

21.

Rotate FREQ RANGE DIAL to 35 (3500 Hz). CALL light should stay on,

NOTE

If R-442/VRC fails the OLD SQUELCH Final Test, replace the A5300 module and repeat

the entire alinement procedure.

5-28. SILICON VERSION A5200A SQUELCH AMPLIFIER ALINEMENT, OLD SQUELCH LEVEL.

PURPOSE. This procedure adjusts the receiver sensitivity to the OLD SQUELCH signals which

include internal noise and the received carrier.

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