Base Assembly
but do not tension them because the clips will be loosened for azimuth adjustments.
Hold-down Wheels: When the hold-down clips are loosened for azimuth adjustments, the antenna leans forward and raises the support ring assembly at the rear of the antenna. To prevent this, four of the hold-down clips are replaced by 4" (102 mm) diameter hold-down wheel assemblies (see Figure 2). The wheels rest on the support ring channel flange as shown in Figure 3.
Make sure all hold-down clips are tight before replacing clips with wheel assembly. When all the wheel assemblies are firmly in place, the remaining hold-down clips should be loosened for azimuth adjustment.
Attach each hold-down wheel to a wheel brack assembly with a 7/8" x 4-1/2" (114 mm) bolt, flat washers, spacer, and nut. Tighten the bolt with the wheel positioned as low as possible. Attach the wheel assembly to the base with 5/8" x 2" (15.9 mm) bolts and nuts (A-325 hardware). Tighten the bolts, but do not tension them.
Turnbuckle Parts: Attach the azimuth ratchet turnbuckle from the base assembly to the support ring assembly as shown in Figure 4. First attach the turnbuckle beam to the
to base Assembly
base assembly with 5/8" x 2" (15.9 mm) bolts and nuts (A-325 hardware). Tighten the bolts, but do not tension them. Attach the azimuth ratchet turnbuckle to the beam with a clevis pin and cotter pins.
Attach the turnbuckle clamp across the upper flange of the support ring assembly as shown in Figure 4. Locate the clamp to allow connection of the free end of the turnbuckle. Secure the clamp by tightening the nut on the 7/8" x 2-3/4" (70 mm) bolt (A-325 hardware) against the welded plate, but do not tension it. Attach the turnbuckle to the clamp with a clevis pin and cotter pins.
Attach the turnbuckle bracket to the inside near surface of the support ring assembly with two 5/8" x 2" (51 mm) bolts, lock washers, and nuts (A-325 hardware). See Figure 5. Tighten bolts, but do not tension them. The elevation turnbuckle is attached when the antenna is placed in the mount as shown in Figure 7.
Anetnna unloading and hoisting instructions are given in Bulletin 237092. Carefully rest the antenna trunnions on the pivot brackets of the mount support ring. Maintain tension on the hoist line until the antenna is secured to avoid possible damage.
Attach the antenna trunnions to the pivot brackets with 1/2" U-bolts, nuts, and Palnuts as shown in Figure 6.