TM
11-5985-284-15
and tighten the cover down with the six
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.
a. Removal and replacement of A1 chassis and
a. Removal. For removal of the loop antenna
left side only (antenna coaxial arm assembly, item
b. Removal and
replacement of
loop antenna
4), omit the procedures in (5) below. All proce-
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-
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,
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.