Albums: WA7DUH And WB7CNV Tower Construction
WA7DUH And WB7CNV Tower Construction
Photo essay of tower project at the station of Linda WB7CNV and Steve WA7DUH. They live just outside of the Richland and West Richland city limits in Benton County. Project is to initially erect a 65 ft guyed tower, but to design it for 75 ft or higher. Benton County has an ordinance controlling "communications facilities" (BCC 11.65) which includes "communication towers and antennas." Many of the requirements are exempted for amateur radio towers and antennas not exceeding 65 ft.P1020490.JPG
Rebar cage for guy station is lowered onto concrete blocks that elevate up off the bottom.
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It looks like coax in this picture, but it is Phillystran, a non-conductive arimid fiber guy wire. Good for about 4,000 lbs pull.
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After assembling 1 of the active elements on the grass by the tower in about 3 hours, assembly was moved into Steve & Linda's shop where an assembly line could be set up, as there are 6 of these to make. Time was reduced to about 1 hour per unit.
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Many parts to each unit..
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Boom joiner on the SteppIR Dream Beam DB18E). Colored dots on the pieces helps the assembler to find and line up the proper pieces.
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A view of the trench heading down to the ham shack. That white bottle in the picture is copper anti-seize/anti-corrosion goop that is used liberally on ALL copper-to-copper connections.
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Although not called for in the assembly manual, on recommendation from Brian W7BJN, a glue bead is placed at each nesting tube junction to prevent them from sliding back in over time. Constant movement in the wind at the top of a tower can cause them to work in according to Brian. Made sense to this crew.
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OK, how to these hollow fiberglass tubes go together??
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Time to pour concrete. The concrete truck can only reach one guy station, so a motorized wheel barrel is used to transport 8 yards of concrete into the main tower and guy station holes.
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One of three ground tower ground rods. The are each connected to a tower leg with both a #4 solid copper wire (per NEC) PLUS a 1 1/2 inch low RF impedance copper strap. Once connections are made, the ground rod is then driven down so it is at least 6 inches below grade.
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Coax switching unit. All three active elements may be driven.
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Left To right: Gary W7TYQ (Yreka CA), Dave W7DJE (Florence, OR) and Steve WA7DUH install the rollers on the hazer. Gary and Dave drove up to help Steve & Linda put this antenna up on the tower.
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Installing the driven element return fixture.
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Driving those ground rods down at least 6 inches below grade with a power hammer.
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Yea-- this is the way to handle concrete.
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A very thick polifin heat shrink tube locks each joint into place.
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Guys from Speedy Angeles Concrete, LLC out of Pasco WA do the work. They have the equipment and muscle, and did the job for a good price.
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Each of the 3 tower grounds are out abot 7 feet from each tower leg, with #4 solid copper and 1 1/2 inch copper strap back to the tower, over to the house electrical ground and down to the ham shack. Two inch rigid non-metal conduit is also buried in the trench to hold 4 runs of LMR-400 coax.
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WB7CNV (Linda) bows properly to the tower gods.