THIS WAS AN INTERESTING ARTICLE FROM
eHow
How to Build a Dipole Antenna
A dipole antenna offers a new ham operator or shortwave listener a simple,
economical means of getting on the air quickly
Adding an antenna tuner allows operation on several frequencies
Constructing and Erecting the Antenna
Instructions
STEP 1: Plan the layout for the dipole. Stretch each dipole leg about 65 feet in a straight line if possible.
STEP 2: Determine what support you'll use for the center insulator. A 30-foot TV mast fixed to house eaves serves nicely.
STEP 3: Attach a small pulley to the mast top.
STEP 4: Run a light rope through the pulley.
STEP 5: Erect the mast.
STEP 6: Obtain 135 feet of wire - 14-gauge should suffice. Scrap wire, either bare or insulated, will work fine.
STEP 7: Obtain the center insulator and leg-end insulators.
STEP 8: Cut the wire in half and then trim each each leg to a resonate at a specific frequency if you like.
STEP 9: Attach one end of each leg to the center insulator, coating the connection with silicone sealant.
STEP 10: Attach the other end of each leg to an end insulator.
STEP 11: Attach coaxial feed line to the center insulator and carry the other end to the point at which it will enter your house.
STEP 12: Use cable ties to secure the coax to the house between the mast and the entrance point.
STEP 13: Attach the center insulator to a rope end and pull it to the top of the mast.
STEP 14: Tie the rope to secure it to the support mast.
STEP 15: Select end supports such as trees, fence posts, garage eaves or an existing TV mast.
STEP 16: Stretch out each leg of wire to its end support.
STEP 17: Thread light rope through the opposite side of the end insulators.
STEP 18: Tie the end insulators to the end supports.
Tips and Warnings
STEP 1: Scrape insulation and corrosion from the wire end at the point it attaches to the center insulator.
STEP 2: Dipole legs don't need to be perfectly straight or horizontal, but you should raise them as high as possible.
STEP 3: Plan on using an antenna tuner so there will be no need to shorten or lengthen antenna legs.
STEP 4: If you trim each leg to 66 feet, 10 inches, the dipole will be resonate at 3.5 mHz. An antenna tuner will allow you to use the dipole and get acceptable performance on frequencies up to 28 mHz.
STEP 5: Do not put any part of the antenna system over, across or near electric lines.
STEP 6: Keep the ends of the antenna at least 8 feet above ground to prevent it from being a hazard to those walking by.
STEP 7: Make sure the antenna mast is mounted directly to the ground; if it isn't, place the ground rod as close to the mast as possible and run a grounding strap to the mast.
Bringing the Feed Line Into the Radio Room
STEP 1: Make certain you have enough coaxial cable to reach the radio room.
STEP 2: Wind up any extra cable and secure it under your radio desk. Extra cable might be necessary if you choose to move the radio.
STEP 3: Find a means of entering the dwelling, such as through a crawl space or gable vent.
STEP 4: Feed the cable from the antenna support mast to the point nearest the radio room.
STEP 5: Drill an adequate hole in the floor or wall.
STEP 6: Feed the cable through the opening.
STEP 7: Attach to the antenna tuner.
STEP 8: Run a separate ground wire (8- or 10-gauge) from the antenna tuner to the ground rod.
STEP 9: Attach the tuner to the radio with a short piece of coax cable.
Tips and Warnings
STEP 1: Type RG-8X coax is a good choice as it's relatively narrow in diameter and has a low loss factor.
STEP 2: Coax cable can be purchased in specific lengths with connectors attached.
STEP 3: Exercise care when drilling through wall panels or flooring.
STEP 4:The ground rod and shunt provide a ground for radio frequencies only. The system is not adequate protection against lightning strikes.
STEP 5: Always disconnect the antenna system during electrical storms
Starting Lengths
The round-a-bout starting lengths for dipoles could be...
160 meter.. Total length 246ft.. Each leg 123ft
80 meter.. Total length 120ft.. Each leg 60ft
40 meter.. Total length 65ft.. Each leg 32.5ft
20 meter.. Total length 32ft.. Each leg 16ft
These lengths are figured by dividing 468 by your frequency. Ex.(468/3.90=120ft)
10, 12 and 15 meter, you'll probably want to use a vertical antenna.
Copyright (c) 2007 David Guy
Page 8
Callsign Lookup Courtesy of QRZ.COM