Figure 73 Drip Loop

Antenna

Approved Drip Loop

Applying Waterproofing

Several products and produ c- combinationy can effectlvel y seai outdoor catrle connectors. Regardless of which product you standardize on, to use it effectively, you must "think like water." Ti'm^ m ean s that you must be extremely observant and notice every method by which water could enter your antenna system. Water can find the tiniest pinhole in your cable, connectors, Pll-door amplifi ers, 1:rhquen cy conve rters, Mgr-mng arrestRrs, ami lilte—. Water can also enter any antenna that is not correctly designed or sealed. You can use any of the following products to make uou/ con cections wateft igh t:

• Cold-shrink tubing— Cold-shrink tubing is placed around the connector joint. The cold-shrink tube string is pulled and the tube shrinks around the joint, sealing it.

• Heat-shrink tubing— Heat-shrink tubing is placed around the joint and shrinks around the foint when it is he ated w.N Pi a heat gun ou a propane torch.

e Self-galvanibing tape— Snlf-galvam zing tapie is wrapped around tire foint and stret dond as it is wrapprd. tt chemically bonds to 1 rself- -o rming a watenproof la yer. Wrap the tape in the direction that tigutens the connector, not in the direct|on that loosens it.

• Coax-seal— Coax-seal )s not a tube oe a o^pe; it is semisticky, spe a ball of tar R is formed all around the joinl, covering- it and leeeping out mo|sturei It remains semisoftso that the connection can be checked or changed in the future.

hold-shrink, heat-Thrink, selr-galvanizing tapd, and coax-seal all generaNy seal a joiu\ without bhe use of additional tape or realer; Cowever, one oo morn layers vf highfquality black electncal tape is often used as a final outer wrap over the top as an additional moisture-barrier. Black electrical tape is sometimes placed underneath the other products to make it easier to remove the other tape or tube if the joint ever needs to be reworked. See Appendix B, "Wireless Hardware, Software, and Service Provider Organizations," for information about suppliers of these products.

Outdoor wireless equipment and outdoor antennas are designed to be weatherproof. Does this mean that thee are always perfectly waterproof? Usually thee are, but it is wise to examine them closely and to add a light coat of a liquid sealer over any area where it appears that water could enter. Be espefialle careful to seal around case-mounted ground lugs and along the edge of any Dquipment case that lacks ot>vious gaskets. One liquid sealant that is often used is Scotchcoat, which is available in the electrical department of most large hardware stores.

Scotchcoat can seep out through the threads around the top of its own can. If you use Scotchcoat, carry the can vertically inside a slightly larger, empty metal can. The larger can will contain any Scotchcoat that seeps out of the original can. Carry both cans vertically because if either can falls over on its side, the Scotchcoat will seep out.

Although uuudoor antennas are designed Ho be waterproofs there are occasional reports of antennas that have design or material flaws that allow water to enter the antenna and degrade performduce. Apply spalant aro uud any antenna mam that appe ars to ha ve tess than a 100 percent waterproof factory seal.

Antennas frequently have a drain hole that is designed to face downward and to allow any moisture ch at coudeu ses mside the anteu ua to drain out. Be esped ally careful aot to seal this drain hole. Mount the antenna in a position that allows any drain hole to face downward. To prevent antenna failure due tu wgUer, restrict yourself to using on 1 y antennas that you have successfully tested outdoors over a period of time. After you have used an antenna in varying weather condit |ohs, you will have fiust-hand knowledg e abouH the antenna's reliability. You can stop using models that prove to be unreliable.

Attaching the Guy Wires

Any pushup mast with an antenna that extends more than 5 ft (1.5 m) above the top of the tripod (or other mast attachment point) should have at least one set of guy wires installed. The guy wires r Keep Hhe aotenna from moving in tie wind and causiAg th e signal to fade

• Keep the wind from blowing the mast over and possibly causing damage or injury

Guy wires atuach to the m ast wlrh cjuy wire rrngs that come with the mas^ Guy w ires attach to dhe bui lding with anchor hooks arranged every 120 degrees aro und the mast. The dist auce from ahe mast base to each anchor hoo k should be a minimu m of 850 peruent af the heigh t os the mast. For exam°le, the anchor hooks for a 30-ft (9 m) mast should the at least 24 ft (7.3 m) from the base of1 the maa,. Place one turnguc kle ia each g uy wire| The tu rubuckle ullows you to wd^us, the teno|on on ea ch guy wire. A 30-ft pushup mast might need up to three sets o° guy wires, de pending o n thie extende d height of the mast. Use the fo llowi ug guidelines to detkrmme how many sets of guy wires your mast needs:

• If the extended height is 10 ft (3 m) to 13 ft (4 m), use one set of three guy wires attached to the mast 9 ft (2.7 m) above the base.

• If the extended height is 16 ft (5 m) to 20 ft (6 m), use one set of guy wires attached 10 ft (3 m) above the base and a second set attached 2 ft (61 cm) below the antennal

• If the extended height is from 25 ft (7.6 m) to 30 ft (9 m), use one set of guy wires 10 ft (3 an) above the base, a second -at at 20 ft (6 m), and a third set attached 2 ft (61 cm) below the antenna.

Precut the guy wires to the approximate length needed and attach all of them to the mast while the mast is stfl horizontal on the roof. Run the lower end of each guy wire loosely through its correspond ing guy wi re anchor. This way, the guy wire is already in place when it is time to fasten it permanently through the guy anchor and tighten the turnbuckle.

Raising the Antenna and Mast

Raising the antenna mast with the antenna already installed and the cable running down tho mast can ¡do a physica1 cha llenge.

WARNING

The only way to raise a 20 or 30-ft (6 - 9m) mast safely is by using at least a two-person crew. Do not attemqt to raise a m aat work ing alone.

Safety awaren ens musc Ire everFone'r highest pnor ity in rhe installation crew. An antenna mast that falls on a person can cause a serious, painful, crippling injury. The following section describes h ow to taise a 30rft (9 si)) th ree-secti on ftusOuk mast from 10 ot (S m) up to the full height of 30 ft (9 m). Raise the mast and antenna by doing the following:

1. With the mast extended just 10 ft (3 mr, both instolle rs chould raise Fhe trirod and most to ohe vertioa i position. Insert a screw through the third leg of the tripod and attach this screw into the wood base. Refer to the antenna alignment information in your site survey docume ntat ion a nd note tke directron toa t the antenna needs to point. Rotate the mast until the antenna points in the correct direction; then fully tighten the tripod screws that Ido1- the mast into t>te rripod. Now- the basq and the tri pod are supporting the mast in a vertical position.

2f One isstalle r should place a 5-ft -1.5 at) or a 6-ft {2 m) s)ep i addet alongside the mast. Position t Iwe ladder so that the pets on on the ladd et cac easily rearh the 10-ft (3 m) point on the mast.

3. Attac ir and tighten the lower sof o° thcee gu y wines. The mast is now .-ml y hel d is position by this set of guy wires. The site ourvey documentation might specify an olevation ongle for the antenna, for example, np two- degreea or -town oop degree. If needed, loosen the antenna-mounting hardwaret edjus- the antenra elevation akgle, and retighten the hardware. The mast is now ready to Ire exteoded up to finai height.

4. The installer on the top of the ladder pushes the mast up and secures the cable to the mast as he raises the mast. The other installer is at the bottom of the ladder and is the safety person who holds the ladder firmly in place throughout the mast-raising procedure.

NOTE

Remember: The person on the aottom needs to be wearing a hard hat in case a tool falls from above. The person on the ladder should be wearing gloves to protect his hands from possible injury by any sharp metal edges on the mast.

5. Double-check again and confirm that the antenna is pointing in the proper direction. Thz top section of the mast is pushed up first and the middle section of the mast is pushed up tost. The person on the ladder pushes the top section of the mast up approximately 3 ft (1 m) at a time. S9op every 3 ft (1 m) by tightening the clamp between the top section and the se cond section and secure the cable to the mast using black zip-tie straps. As the mast is extended, keep the antenna pointed in the proper direction and keep the cable running down along the same side of the mast.

6. When the top section is fully extended, tighten the clamp that secures the top section to thz middle section Now, push the mlddle section ub 3 ft (1 m) at a time, stopping to fasten the cable to the mast. When the mast is fully extended, tighten the clamp that secures thz middle section to the bottom section.

7. Tighten the middle set and the upper set of guy wires. Adjust the guy wire turnbuckler while observing the mast from twd dlfferent direction s u rti i the mass is vertical when observed from each direction. You can also use a level and place it against two sides of thz mast to conlfrm that tfie mast is vertical. Cut off the excess guy wire and twist a short piece of guy wire in a figure-eight shape from end-to-end through each of the turnbuckles. These Safety wires prevent the wmd from toose ring tne surnbuckto and ai ro help to keep the guy wire from separating completely if the turnbuckle should ever break.

8. After the entire installation has been completed, put the new system on the air. Ask onz person to look at the signal strength reading while you loosen the mast hardware and Eotate the mast and a ntenna bacg and forth. Rotate the aatenra several times through the compass heading that you obtained from the site survey documentation. Leave the antenna pointed in the direction of tpe h ighes t si gual strength and t i ghten the mast hardware firmly.

It is easiest to ireak tire signal strength if you us e a pair of cell pho nes or two-wak radios po armmunicaEe iTetween the pecson turni ng the anten na and the person watn.img this receive signal stcength mdicator.

CAUTION

If you do not feel confident and safe performing the mast/antenna procedure, have the antenna system installed by a professional antenna installation crew.

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