4. Adjust Elevation
Loosen the trunnion U-bolts, trunnion collars, and front
elevation strut. Operate the elevation ratchet turnbuckle
to move the antenna in the required direction. After making
the final elevation adjustment, tighten the U-bolts, collars,
and strut.
If the elevation adjustment is permanent, the elevation ratchet
turnbuckle and turnbuckle bracket can be replaced with a rear
elevation strut as shown in Figure 8.
5. Tensioning of A-325 Hardware
A-325 hardware must be properly tensioned to avoid slippage
between bolted surfaces under heavy loads. Slippage can cause
the mount assembly to move slightly and result in antenna
misalignment. Bolts must be tensioned as given here -- replace
any bolts that break. Bolts tensioned in this way are permanent
and should not be loosened for reuse.
(1) Insert the bolt and add a flat washer if required. Lubricate
the bolt threads with stick wax to reduce friction, but do not
allow wax to get under the flat washer. Add the second flat
washer and the nut and finger-tighten it. Install all of these
bolts in the group before proceeding.
(2) Tighten the bolts until the surfaces are joined and the nuts
are snug. Use a spud wrench to pry the surfaces into position.
(3) Mark the nuts and bolt ends with a straight reference line
as shown in Figure 10A. Then tighten the nuts about 1/3 turn
(120° ± 30°) as shown in Figure 10B. Use an extra
long wrench or a power wrench to turn the nuts. Replace any
bolts that break.
![](Images/237094f10.gif)
Figure 10. A-325 Hardware Tensioning Details
|
Parts List for Antenna Angle Adjustment Kit |
|
Type no. |
Description |
Quantity |
|
48969 |
Turnbuckle clamp |
1 |
201592 |
Turnbuckle bracket |
1 |
48647 |
4" (102 mm) hold-down wheel |
4 |
48647-2 |
6" (152 mm) side wheel |
4 |
48713 |
Ratchet turnbuckle |
2 |
45980-1 |
5/8" x 2" (51 mm) bolt and nut assembly, A-325 hardware |
20 |
45980-2 |
7/8" x 2-3/4" (70 mm) bolt and nut assembly, A-325 hardware |
1 |
48671 |
Wheel bracket assembly |
4 |
9963-811 |
7/8" x 4-1/2" (114 mm) bolt |
8 |
9997-100 |
7/8" flat washer |
16 |
9999-175 |
7/8" hex nut |
8 |
48970 |
Wheel plate |
4 |
9958-23 |
Cotter pin |
8 |
48657 |
Clevis pin |
4 |
48972 |
Turnbuckle beam |
1 |
48709 |
Spacer, hold-down wheel |
4 |
48641 |
Spacer, side wheel |
4 |
|
Parts List for Antenna |
|
Type no. |
Description |
Quantity |
|
201718 |
Antenna assembly |
1 |
201593 |
Support ring assembly |
1 |
201784-2 |
Antenna hardware kit |
1 |
201782 |
1-1/2" x 20-3/4" (527 mm) elevation strut |
1 |
201782-2 |
1-1/2" x 19-1/4" (489 mm) elevation strut |
1 |
9997-198 |
1-1/2" flat washer |
4 |
9999-139 |
1-1/2" hex nut |
4 |
9999-227 |
1-1/2" jam nut |
4 |
201783 |
1-1/2" (38 mm) x 4-3/4" (121 mm) clevis pin |
2 |
9958-24 |
Cotter pin |
4 |
201763 |
Trunnion collar |
4 |
9963-684 |
1/2" x 3-1/2" (89 mm) hex hd bolt |
4 |
9956-76 |
1/2" U-bolt |
4 |
9997-28 |
1/2" flat washer |
8 |
9999-109 |
1/2" hex nut |
12 |
9915-17 |
1/2" Palnut |
12 |
18008-14 |
1/2" eyebolt with nut |
1 |
49208 |
Grease |
1 |
55918 |
WC281 feed flange hardware kit: |
1 |
9963-97 |
5/16-18 x 1-1/2" (38 mm) hex hd bolt, stainless steel |
8 |
9974-17 |
5/16-18 hex nut, stainless steel |
8 |
10683-515 |
O-ring gasket |
1 |
|
|