TM 11-5985-357-13procedure of figur

TM 11-5985-357-13
procedure of figure 6-7 if required reading is not obtained.
6-4. Feedcone Disassembly and Assembly Procedures
a. Removal of Balun Housing Assembly.
(1) Remove the four screws that hold the balun
housing to the feedcone subassembly (fig. 6–2).
(2) Separate the balun housing from the feedcone
assembly exposing the black and white wire
leads connecting the balun to the feedcone subassembly
(fig. 6-3).
(3) Remove the two screws that secure the #4
(white) and #6 (black) wire lead terminal to the feedcone
structure (fig. 6-3). The balun assembly is now
detached from the feedcone subassembly.
b. Assembling the Balun Housing Assembly.
(1) Align balun gasket to the feedcone subassembly
(fig. 6-3).
(2) Align the balun assembly with the feedcone
subassembly (fig. 6-3).
(3) Screw the two screws that secure the #4
(white) and #6 (black) wire lead terminals to the feedcone
structure (fig. 6–3).
(4) Insert the four screws through the holes in
the balun housing and screw into the feedcone subassembly
(fig. 6-2).
6-5. Balun Disassembly and Assembly Procedures
a. Disassembly (fig. 6-4 and 6-5)
(1) Unsolder the white lead from the center pin
of the UG—680/U connector and the black lead from
the connector ground lug.
(2) Remove the balun subassembly from the
balun housing.
(3) Remove the connector retaining nut using a
socket or end wrench.
(4) Repair or replace defective parts.
b. Assembly (fig. 6-4, 6-5 and 6-6).
(1) Assemble the UG-680/U connector to the
balun housing with the connector protection bracket
assembly, gasket connector, washer, lockwasher and
ground lug (fig. 6-6).
(2) Insert balun subassembly (fig. 6-5) and
resolder white lead to the center pin of the
UG–680/U connector and the black lead to the connector
ground (fig. 6-4),
6-6. Final Assembly Inspection
The electrical troubles that occur in the AS-
3166/GRC are open circuits, short circuits, and poor
connections. These troubles can be isolated by making
continuity checks, using Multimeter TS–352B/U.
The procedures are listed below.
a. Place the antenna base on an insulated surface.
b. Check the continuity between the radial element
sockets and the UG-680/U connector pin on the feedcone
assembly (fig. 6-2) using a low resistance range
on the ohmmeter. The resistance should be near zero.
c. Check the continuity between the UG–680/U
connector center pin and outer conductor using a low
resistance range on the ohmmeter. The resistance
should be zero.
d. Units that pass inspection may now be placed in
service.
Figure 6-4. Unsoldering wire leads.
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