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How to Build Your Own Beam Antenna

Beam antennas, also known as Yagi antennas, are commonly used in ham radio operation. Beam antennas use a series of elements to send and receive transmissions in a focused direction, rather than 360 degrees as in omnidirectional designs. They can be as large or as small as needed. A simple version is something even the novice hobbyist can attempt. Once completed, you can send and receive transmissions surprisingly well, given the low cost and simple nature of the design and materials.

Things You'll Need

Measuring tape
2-by-2 inch, 12-inch long plastic decking rail
Fine-tip marker
6 feet of 1/8-inch copper pipe
Drill
1/8 inch drill bit
Rubber mallet
Soldering iron
Lead-free solder
BNC-terminated RG-58 coaxial cable
Coaxial cutters
Coaxial strippers
Electrical tape

Instructions

- 1
  Measure out five locations on the plastic decking rail starting at two inches from the top. Mark a second six inches below the first, and other six inches below that. Mark two more locations three inches apart, adding another mark a half of an inch below the lowest one.
- 2
  Drill out holes at the marked locations, completely penetrating the rail. Do not drill completely through the last hole at the very bottom.
- 3
  Measure out five lengths of copper pipe. Your measurements are 11 3/4, 12 1/4, 12 1/2, 13 1/2 and 20 inches. Bend the copper pipe repeatedly, or cut it, at these measured points to break the sections off cleanly.
- 4
  Bend the 20-inch-long section into a "J" shape by wrapping it around the handle of a hammer. The long section of the "J" is 13 inches, with the hook of the "J" remaining at seven inches.
- 5
  Slide the copper pipe lengths through the holes in the plastic decking. Push the element rods in order of ascending length from top to bottom, centering each. Tap the rods through the rail with a rubber mallet if that is necessary to achieve insertion.
- 6
  Orient the short end of the bent "J" pipe so the short end of the "J" fits into the lowest hole on the rail, with the longer end penetrating the rail.
- 7
  Tap flat each exposed end of each pipe to reduce wind load. This reduces stress on the antenna and/or mounting apparatus as wind gusts blow across the array.
- 8
  Cut the RG-58 coaxial cable to the desired length, leaving one of the pre-terminated BNC connectors intact at one end.
- 9
  Strip two inches from the snipped end of the coaxial cable. Twist the braided copper or foil shield into a pigtail. Separate the center conductor and pigtail by hand.
- 10
  Solder the center conductor in the coaxial cable to the short section of the "J" element at the bottom of the array.
- 11
  Solder the shield pigtail to the longer end. Both solder connections are made on the same side of the deck railing.
- 12
  Wrap the exposed solder joints with electrical tape to insulate them. Apply another two to three passes of tape to the coaxial cable down to the beam for strain relief on the solder connections.

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