Section IV. EMERGENCY OPERATION PROCEDURES

TM 11-5895-833-12/NAVELEX 0967-LP-550-1010/TO 31R5-2TSC54-91

Section IV. EMERGENCY OPERATION PROCEDURES

The C-field and 1 pps of the cesium beam

3-13. Operation with Down-Converter

frequency standard should not be adjusted except

Failure

by direction from NAVOBSY. Instruc-tions and

If a down-converter carrying high-priority traffic fails, an

procedures for the operation and reporting of data

unused down-converter or a down-converter carrying

is contained in NAVOBSY TS/PTTI- O1M.

low-priority traffic may be substituted for the defective

unit as follows:

3-15. Operation with Cesium Beam Frequency

a. Patch substitute down-converter output to output

Standard Failure

line normally used by defective unit.

b. Check to see that proper filter is connected

All communications channel frequency synthesizers are

between connector J2 on rf input stripline assembly and

normally slaved to the 5-MHz standard frequency from

connector J1 on rf conversion stripline assembly (para 3-

the cesium beam frequency standard, providing coherent

9b).

operation. The tracking receiver frequency synthesizer

c. On substitute down-converter front panel, set

1A5 and the test translator are normally driven by their

RECEIVE FREQUENCY SELECTOR MHz and MODE

internal 5-MHz signal sources, providing noncoherent

SELECTOR switches to the same frequency and mode

operation. If the cesium beam frequency standard fails,

settings as on the defective unit.

and coherent operation of the communications channel

d. Perform the procedures outlined in paragraph 3-

frequency synthesizers must be maintained, perform the

9b(4) through (9).

patching operations de-scribed in a below. If the cesium

beam frequency standard fails and noncoherent

operation of the com-munications channel frequency

3-14. Operation with Up-Converter Failure

synthesizers is permitted, perform the patching

operations described in b be-low.

If an up-converter carrying high-priority traffic fails, an

unused up-converter or an up-converter carrying low-

a. Coherent Operation Patching.

priority traffic may be substituted for the defective unit as

(1) Disconnect coaxial looping plug connected

follows:

between 2A9 jack J17 and 2A6 jack J18 (fig 3-8)

(2) Disconnect 50-ohm coaxial termination from

a. Set both up-converter RF OUTPUT switches to

1A5 jack J1 (fig. 3-3).

OFF-LINE.

(3) Connect patch cord between lA5 jack J1 ((2)

b. Patch substitute up-converter input to input line

above) and 2A6 jack ((1) above) J18.

normally used by defective unit.

b. Noncoherent Operation Patching.

c. Set TRANSMIT FREQUENCY SELECTOR MHz

(1) Disconnect jumper cable from frequency

and MODE SELECTOR switches on substitute up-con-

synthesizer EXT STD OUT connector J3.

verter to the same frequency and mode settings as on

(2) Connect open end of the jumper cable ((1)

the defective unit.

above) to INT STD OUT connector J1.

d. Perform the procedures outlined in paragraph 3-

9a(4) through (10).

NOTE

3-21