Removal and Replacement of Chassis and Components

11-5985-284-15

and tighten the cover down with the six

4-9. Repairs

captive screws.

Most of the parts in Antenna AT-1082/PRC can

4-11. Replacement of Loop Antenna Arms

be reached easily without special procedures. The

repair duties of a direct support maintenance re-

To replace loop antenna arms, follow the pro-

pairman are limited to the repair procedures listed

cedures outlined in a and b below. For item num-

below.

bers given in a and b below, refer to figure 4-6.

a. Removal and replacement of A1 chassis and

a. Removal. For removal of the loop antenna

components (para 4-10) .

left side only (antenna coaxial arm assembly, item

b. Removal and replacement of loop antenna

4), omit the procedures in (5) below. All proce-

arms (para 4-11).

dures listed are required for removal of both loop

antenna sides (items 3 and 4). Item 3 (antenna

Caution: Be careful when handling inductors

arm assembly) is the loop antenna right side.

and rotor assemblies. Do not bend these parts.

(1) If possible, set the loop antenna into its

4-10. Removal and Replacement of Chassis

operating position.

(2) Unscrew the six cover screws, and re-

and Components

move the cover (1) from the case (2).

a. Removal (figs. 4-5 and 4-6).

(3) On the side of the loop antenna to be

(1) Remove the six captive cover screws hold-

removed, antenna arm assembly (3) and/

ing the cover to the case.

or antenna coaxial arm assembly (4), pull

(2) Loosen the three retaining screws on the

the E-ring (5) from its mounting.

three knobs; remove the knobs.

(4) Unscrew the coupling cap (6), and slide

(3) Unsolder the wire from connector J1 to

it to the sense whip antenna as far as

the ATTENUATOR switch.

possible.

(4) Remove the three hex nuts holding the

(5) For removal of antenna coaxial arm as-

control shafts in position.

sembly (4), remove the leaf springs (7

(5) Lift the chassis up and out of the case.

and 8) that are mounted on the case.

(6) For the removal of switch assembly A1S1

(6) Unsolder the tinned copper wire (9)

or A2S1, capacitor C1, or connector J1,

from the contact plug (10). When heat-

unsolder the connections, unscrew the as-

ing contact plug (10), hold the soldering

sociated shaft nut, and lift the released

iron there and push the top portion of

item up from the chassis.

the antenna arm assembly (3 or 4) to be

b. Replacement.

removed while having an assistant repair-

(1) Mount connector J1 to the case, and solder

man press the contact point of that assem-

its ground connection.

bly from the case (2).

Mount the switch assembly (A1S1 and/or

Caution: Once the tinned copper

A2S1) and capacitor C1 on the chassis,

wire (9) has been removed from the

and screw on the associated shaft nut.

contact plug (10), remove the solder-

Place the chassis back in the case, and

tighten the three hex nuts on the control

ing iron. This will prevent damage to

either antenna arm assembly side (3

shafts of A1S1, A2S1, and C1. Then,

or 4) of the loop antenna.

attach the switch knobs.

Install the six mounting screws for hold-

(7) After the desired antenna arm assembly

ing tile chassis to the case.

(3 or 4) has been dismounted, remove

Solder the connections of the replaced

O-rings (11) and spring washer (12) as

items, and solder in capacitors C2 and C3,

required. If antenna coaxial arm assem-

if required.

bly (4) has been dismounted, remove the

(6) Solder the wire from ATTENUATOR

nut from the contact plug (10), lock-

switch A2S1 connector to J1.

washer (13), cent act plug (10), cap

(7) Place the cover on the case, making sure

bearing (14), and coupling cap (6), as

that the rubber gasket is seated properly,

required.

4-10