Replacement of Coaxial Isolation 1A1HY1

TM 11-5820-695-35

CAUTION

b. Replacement

Removal of rigid coaxial cables must

(1) Align the replacement Isolator assembly

be performed carefully to prevent

with the four screw holes In the 1 Al 1 Enclosure.

damage to the rigid coaxial cables.

Replace and tighten the four machine screws, securing

the Isolator assembly to the enclosure plate

(3) Disconnect rigid coaxial cables lW17 and

(2) Reconnect RF cable W1 to connection J1.

1W19 from coaxial circulator 1HY1 (TM 115820-695-

Reconnect RF cable W2 to connector J2

12).

(3) Reinstall assembly 1All on plate assembly

(4) Remove the four screws and washers

1A16

securing the dc monitor bracket, on which coaxial

(4) Set the POWER ON/OFF switch on Meter

circulator IHY1 is mounted, to plate assembly 1A16.

panel assembly 1 A1 5A8 to ON

The remove dc monitor bracket and coaxial circulator

IHY1 from plate assembly 1A16.

3-29. Replacement of Digital Data Modem Chassis

(5) Remove the three screws and washers

1A12A12

securing coaxial circulator 1HY1 to the dc monitor

(fig. 3-1 and 3-13)

bracket.

a. Removal.

b. Replacement.

(1) Mount replacement coaxial circulator

(1) Set the POWER ON/OFF switch on meter

1HY1 on the dc monitor bracket and align the three

panel assembly 1A15A8 to OFF.

mounting holes. Then secure coaxial circulator IHY1 to

(2) Disconnect coaxial cables 1A15W1,

dc monitor bracket, using the three screws and washers

1A15W2, 1A15W4, 1A15W7 and 1A15W10 from digital

removed in step a(5).

data modem 1A12.

(2) Place dc monitor bracket with coaxial

(3) Loosen the two assembly captive screws

circulator 1HY1 on plate assembly A16 and align the

securing digital data modem IA12 to electrical

four mounting holes. Then secure dc monitor bracket to

equipment cabinet lA15 by alternately turning each

plate assembly 1A16 using the four screws and washers

captive screw two turns at a time until the captive

removed in step a(4).

screws turn freely. Withdraw digital data modem 1A12

CAUTION

from electrical equipment cabinet 1A15.

Replacement of rigid coaxial cables

(4) Loosen the three cover captive screws

must be performed carefully to

securing the hinged front cover and lower cover.

prevent damage to the rigid coaxial

(5) Using a card extractor carefully remove

cables.

plug-in components 1A12A2 through 1A12A10 from

digital data modem chassis 1A12A12 (TM 11-5820-69-

(3) Connect rigid coaxial cables 1W17 and

12).

1W19 (TM 11-820-696-12).

(6) Loosen the two captive screws securing

(4) Connect coaxial cable IA16W18 to co

plug-in components lA12A1 and 1A12All to digital data

axial circulator 1HY1 connector DC MONITOR J3.

modem chassis 1A12A12.

(5) Set the POWER ON/OFF switch on meter

(7) Using the two loosened captive screws as

panel assembly 1A15AS to ON.

hand grips, slowly pull 1A12A1 and 1A12A11 from their

position in digital data modem chassis 1A12A12.

(6) Perform the T-1054/GRCJ144 frequency

multiplier metering circuit calibration procedure (para 3-

(8) Close and secure the hinged cover of

59).

defective digital data modem chassis 1A12A12 by

tightening the three cover captive screws.

3-28.1. Replacement of Coaxial Isolation 1A1HY1

(fig

3-3.1, 5-27.1)

b. Replacement.

a. Removal

(1) Loosen the three cover captive screws

(1) Set the POWER ON/OFF switch on meter

that secure the cover to the replacement digital data

panel assembly 1 A1 5A8 to OFF.

modem chassis 1A12A12, and lower the cover.

(2) Remove assembly 1 Al 1 from plate

(2) Carefully

insert

plug-in

assembly 1 A1 6.

components1A12A1 through 1A12Atl, removed in step

a(5) through

(3) Disconnect RF cables W1 and W2 from

J1 and J2 connectors on the isolator assembly.

(7) into their respective positions in 1A12A12

as indicated on the hinged cover of 1A12.

(4) Loosen and remove the four pan head

machine screws which secure the circulator 1 Al 1

enclosure. Remove the isolator assembly.

Change 5

3-50