6-1. Scope of Direct Support Mainte

6-1. Scope of Direct Support Maintenance
Direct support maintenance includes those in a and b
below in addition to the duties prescribed for
organizational maintenance (chap 4). Repair parts are
listed in TM 11–5985–357-23P.
a. Repair of the feedcone assembly including
replacement of the feedcone subassembly or
UG-680/U and the repair of broken lead wires.
b. Repair of Cable Assembly, Radio Frequency
CG-1889C/U (fig. 6-7).
6-2. Tools, Test Equipment, and Materials Required
a. Tools. Tool Kit,
100/G.
b. Test Equipment.
c. Materials. See
materials.
Electronic Equipment TK–
Multimeter TS–352B/U.
appendix E for available
6-3. Direct Support Troubleshooting
a. Feedcone Subassembly (fig. 6-2 and 6–3).
(1) Visual inspection.
(a) Inspect the six radiating element female
sockets for evidence of an interference fit when mated
with an MS-116A antenna element.
(b) Inspect the Lexan insulator assembly and
adhesive joint for cracks or evidence of deterioration.
(c) Inspect the four helical coils on the Lexan
insulator for stripping or physical deterioration.
(d) Inspect the three helical coils on the upper
and lower cone castings for stripping or physical
deterioration.
(e) Clean out the weep holes (fig. 6–2).
(2) Continuity check. Place the feedcone subassembly
on an insulated surface. Check the continuity
between the radial element sockets and the
associated #4 or #6 terminal using a low resistance
range on the ohmmeter (fig. 6–3). The resistance
should be near zero.
Figure 6-