Element Fabrication The PVC is then placed so that the aluminum extends 1 inch past the bottom of the PVC. Place the U-Clamps in the hinge 2 x 4 in the holes previously drilled, and use the end piece (flat metal with the 2 holes) on the opposite side such that when the pole is mounted and the U-Clamp tightened, the 2 x 4 is held in compression. Place the aluminum and PVC into the U-Clamps and tighten down, with the PVC secured at the bottom of the 2 x 4, and the aluminum extending an inch further out of the PVC. Tighten down all clamps so that the aluminum will be secured by the clamps. The element consists of a length of 2 inch outside diameter 6061 T6 thick walled aluminum tubing (used in antenna boom material) or Schedule 40 Aluminum tubing, 20 feet in length. A 5 foot length of 2 inch schedule 80 PVC surrounds the bottom of this mast, and the fiberglass telescoping pole (available from Spiderbeam - http://www.spiderbeam.net/sb/home/index.php Spiderbeam HD 12m fiberglass pole MF120001) which is also sold by Wireman (http://thewireman.com/products.html ). |
| The fiberglass pole is extended to full length, and at each telescoping segment, duck tape is wrapped to secure the joint and ensure the joint does not fail. At the bottom of the pole, I placed a 2 ½ - 1 ¾ inch hose clamp to ensure that the bottom of the fiberglass does not split, when this fiberglass is placed over the top of the aluminum pole. At the top of the aluminum pole, I wrapped several layers of duck tape to also ensure that the inside diameter of the fiberglass pole (slightly larger than 2 inches) has a snug fit to the aluminum. The fiberglass pole is then placed over the top 12 inches of the aluminum pole, and secured with the hose clamp, and a second hose clamp around the 2 inch aluminum pole ensures the fiberglass will not slip down the aluminum. |
The PVC is then placed so that the aluminum extends 1 inch past the bottom of the PVC. Place the U-Clamps in the hinge 2 x 4 in the holes previously drilled, and use the end piece (flat metal with the 2 holes) on the opposite side such that when the pole is mounted and the U-Clamp tightened, the 2 x 4 is held in compression. Place the aluminum and PVC into the U-Clamps and tighten down, with the PVC secured at the bottom of the 2 x 4, and the aluminum extending an inch further out of the PVC. Tighten down all clamps so that the aluminum will be secured by the clamps Place the coil centered on a point 17 feet from the bottom of the telescoping fiberglass and secure the coil in place, using the brass strip and 8 x 32 by 1 ½ inch machine screw and nut. Do not over tighten the clamp as it may damage the fiberglass. The shorter wires are placed on the bottom of the coil mount, and the longer wires are placed on the top of the coil mount. Dress the bottom wire evenly around the fiberglass and wrap with duck tape to hold in place. Continue dressing the 3 wires so that they remain evenly spaced around the fiberglass. At each telescoping section, secure the wires to the fiberglass using duck tape. At the aluminum pole end, strip back 1 inch of insulation from the 14 AWG solid wire, and place this wire under a 1 ¾ to 2 ¼ inch stainless steel hose clamp. Place a thin layer of Nolox conductive grease under the hose clamp before placing the wire. Tighten the holes clamp such that the wire makes a solid connection. Do not over tighten as it can strip the thread from the hose clamp. Wrap the entire connection with duck tape. Dress the top wires above the coil as per the lower wiring. When you reach the very top of the fiberglass, wrap all 3 wires together, and continue to wrap for 1 additional foot making an extension above the fiberglass. Then strip back the insulation from each end, twist the bare copper, and solder. Do not cover this end with tape as it can add additional weight to the end. . |