CRYSTAL REFERENCE SYSTEM (CRS) TEST. - TM-11-5820-401-34-30177

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

3-15. CRYSTAL REFERENCE SYSTEM (CRS) TEST.

PURPOSE. This test is performed to make sure that the local oscillator will not be pulled off frequen-

cy by a malfunctioning CRS. Steps 1 through 8 involve a quick check to determine whether the CRS is

putting out an incorrect error signal causing improper local oscillator frequency and loss of audio

tone. The remaining steps are done with the local oscillator disconnected from the CRS in order to

check CRS performance in response to a nonfluctuating 42.00-MHz signal generator output. If the

CRS passes the second part of the test, it will be able to correct normal fluctuation in Iocal oscillator

frequency.

TEST EQUIPMENT AND MATERIALS

T-Connector UG-274/U

Signal Generator AN/URM-103

Loudspeaker LS-454/U

Frequency Counter AN/USM-207

Multimeter ME-26(*)/U

Power Supply PP-1 104 (*)/G

Amphenol Adapter M-39012/16

Maintenance Kit MK-1978/VRC

Matching Unit CN-901/U

TEST SETUP. Connect the equipment as shown in test setup diagram

. Remove R-442/ VRC top

and bottom covers. (See paragraph 2-7.)

INITIAL EQUIPMENT CONTROL SETTINGS. Set equipment controls as indicated in the following

table. If using alternate equipment, inject 100-v rf at 30 MHz, 1-kHz modulation, and 8-kHz

deviation.

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