Tensioning Step | Andrew 3.7-Meter Earth Station Antenna manual

A-325 Tensioning

Step 1

Step 2

Step 3

Step 4

Step 5

Step 6

During the installation process, there are several references to the A-325 hardware ten- sioning procedure. The A-325 hardware must be properly tensioned to avoid slippage between bolted surfaces under high loads. Slippage can cause the corresponding assembly to move, causing antenna misalignment. When designated, the A-325 hard- ware should be tightened according to the following tensioning procedure.

NOTE: Tensioned bolts are for final connections only and should not be loosened for reuse.

Lubricate the bolt threads with the provided stick wax to reduce friction.

Insert the bolt, and add a flat washer—if required. Do not allow wax under the flat washer.

Add the nut, and finger tighten.

After the connections are complete, tighten the bolts until the surfaces are joined and the nuts are snug (for example, full effort of a person using an ordinary spud wrench). Do not proceed with Steps 5 and 6, unless the connection is final and is not intended to be loosened again.

Note: If the bolts are loosened after Steps 5 and 6, discard and replace with new hard- ware.

Using a felt-tip marker, mark the nuts and the ends of the bolts with a straight line as shown in Figure 3-1a and Figure 3-1b.

Tighten the nuts further with an extra long wrench until the nuts are moved 1/3 turn (120 degrees) as shown in Figure 3-1a for bolt lengths less than four diameters and 1/2 turn (180 degrees) as shown in Figure 3-1b for bolt lengths over four diameters.

Use Felt Marker

Before After

Tensioning Tensioning

Figure 3-1a: A-325 Tensioning Procedure For bolts less than 4 diameters