LOCAL OSCILLATOR A1500 ALINEMENT. - TM-11-5820-401-34-30180

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

3-15.

CRYSTAL REFERENCE SYSTEM (CRS) TEST. (CONT)

9. Set R-442/VRC MC-TUNE-KC control to 30.50 MHz.

10. Remove rf cable and matching unit from AN/URM-103 LO-RF jack an insert in HI-RF jack.

11. Remove P1004 from J1004 on A1000 tray. (See test setup diagram

12. Remove rf cable from ANT jack on the R-442/VRC.

13. Using Amphenol Adapter M-39012/16, connect rf cable to P1004.

14. Connect AN/USM-207 frequency counter to T-connector.

15. Set AN/URM-103 signal generator RF OUTPUT control to 125 KUV.

16. Adjust AN/URM-103 RF TUNING control for 42.00-MHz output. Verify frequency on frequency

counter.

17. Set Multimeter ME-26(*)/U to 3-vdc scale and turn ZERO ADJ for midscale reading.

18. Connect ME-26(*)/U positive lead to TP3001 (3) and negative lead to ground.

19. Check reading on ME-26 (*)/U. Meter should read zero vdc (midscale), with slight

fluctuation.

NOTE

If ME-26(*)/U reads greater than +0.32 vdc or less than -0.32 vdc, the CRS is defec-

tive. See the troubleshooting section.

In steps 20 and 21, ME-26(*)/U should vary smoothly at least +0.5 vdc and then at least

-0.5 vdc. If not, the CRS is defective. See the troubleshooting section.

20.

Slowly turn AN/URM-103 RF TUNING control to increase output frequency to 42.25 MHz. Note

change in reading on ME-26(*)/U.

21. Slowly turn AN/URM-103 RF TUNING control to decrease output frequency to 41.75 MHz. Note

change in reading on ME-26 (*)/U.

22. Proceed to paragraph 3-16, Local Oscillator A1500 Alinement.

3-16.

LOCAL OSCILLATOR A1500 ALINEMENT.

PURPOSE. If the local oscillator is operating at the correct frequency, the CRS will not output a dc

error signal. This procedure alines the oscillator by tuning its circuits to bring the CRS error signal as

close to zero as possible. The Crystal Reference System Test (paragraph 3-15) must be done prior to

performing this alinement.

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