CONTROL AND SWITCH SETTINGS - TM-11-5820-670-300131

TM 11-5820-670-30

2-19. HOMING SENSITIVITY TEST. (CONT)

CONTROL AND SWITCH SETTINGS

POSITION/SETTING

CONTROL OR SWITCH

EQUIPMENT

HOME

TS-2575/ARC-131

MODE SWITCH

CARR

SQUELCH

31.00 MHz

FREQ sel

LEFT and RIGHT HOMER ATTEN

Adjust to 31.00 MHz.

BAND SWITCH and RF TUNING control

AN/URM-103

MOD OFF

FUNCTION switch

LO 0-10 KUV

RF OUTPUT switch

LO-HI RF SET to LINE control and

Adjust as required in

LO RF UV

procedure.

TEST PROCEDURE

1. Increase AN/URM-103 output by adjusting LO RF UV control until flags on homing Indicator

lD-48A/ARN disappear.

2. Divide by two the AN/URM-103 dial indication observed in step 1.

STANDARD. 1.2 microvolt maximum

3. If quotient is more than 1.2 microvolt, see troubleshooting chart 2-22.

4. Repeat steps 1 through 3 adjusting test set for frequencies of 50.50 MHz and

68.95 MHz.

5. Set test set LEFT HOMER ATTEN control to 3 db and RIGHT HOMER ATTEN to 6 db.

6. Adjust AN/URM-103 Attenuator control for a 12 microvolt output signal.

7. Set frequency selectors to 31.00 MHz and tune AN/URM-103 to receiver frequency. Ob-

serve and record deflection of lD-48/ARN vertical needle.

STANDARD. Left length of wing minimum

8. If deflection of vertical needle does not meet requirement of the standard, see trouble-

shooting chart 2-23.

9. Reverse db settings of RIGHT and LEFT HOMER ATTEN. Record needle deflection.

STANDARD. Right length of wing minimum

10. If deflection of needle does not meet requirement of the standard, see troubleshooting

chart 2-23.

11. Repeat steps 5 through 10 adjusting frequency selectors of test set for frequencies of

50.50 MHz and 68.95 MHz.

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