How to Build an HDTV Antennaby Nichole Liandi
With the growth of local television stations offering over-the-air high definition television (HDTV) broadcasts, many viewers now enjoy watching HDTV broadcast without having to pay a cable or satellite provider for an HD programming package. The performance of some commercially available antennas has proven disappointing, particularly antennas that were designed with more forgiving analog signals in mind. And with the switch to digital broadcasts, those who relied on over-the-air transmissions many have found their reception compromised by their antenna. This inexpensive and simple antenna is a directional "bowtie" array that has proven effective at receiving HDTV broadcasts.
Take the coat hangers, cut off the "head" of each, and cut them in two so that you have eight V-shaped pieces. Sand each piece with sandpaper at the apex of the V to remove any paint or other coating from the metal.
Cut a 48-inch long piece of 2- by 4-inch board with a saw. Start 6 inches from one end, on the narrow side of the board, and screw in two wood screws and washers next to each other every 6 inches, until you have put screwed in four pairs. Add a final pair of washers and screws halfway between the second and third pairs, for a total of five pairs of washers and screws.
Slide the V-shaped wire elements underneath the washers and tighten the screws to hold them in place. The open end of the V's will be facing away from the board. Leave the middle set of screws and washers open. When you're finished you'll have four pairs of V-shaped wire elements mounted on the board.
Cut four 9-inch long pieces of heavy wire, 12- or14-gauge is appropriate. Scrap electrical wire works well for this. Connect two pieces to each of the washers and screws in the center -- the ones you haven't used yet. Then run each individual wire along the length of the board, attaching it to the screws holding the V-shaped wire elements you've already mounted. Cross the wires before attaching to the last element of the antenna, and make sure that the wires are insulated -- A piece of tape will work fine for this -- where they cross. See the diagram for the wiring.
Attach the terminals of a 300-ohm transformer to the center set of washers and screws. Loosen the screws and slide the terminals underneath, then tighten the screws.
Cut a 30- by 24-inch piece of heavy cardboard with scissors. Cover one side with aluminum foil held on with tape.
Take a staple gun and attach the aluminum foil-covered cardboard to the side of the 2 by 4, opposite the V-shaped elements, with the foil side of the cardboard facing the elements. This piece of cardboard acts as a reflector for the antenna.
To use the antenna, plug your antenna line into the transformer, set the antenna up vertically so that the wire elements are one above the other and point it in the direction of the transmitter of the television station that you want to receive.
- For a more durable antenna, make the reflector out of light wood, covered in metalized duct tape.
Items you will need
- Four metal coat hangers
- Wire cutters
- Tape measure
- 2- by 4-inch piece of lumber
- Wood screws
- 12- or 14-gauge wire
- 300- to 75-ohm transformer
- Cardboard (30 by 24 inches)
- Aluminum foil
- ARRL Antenna Handbook; ARRL; 2006
- HDTV For Dummies; Danny Briere and Pat Hurley; 2007