Make a High Performance Indoor/Attic Dtv Antenna
If you don't have cable or satellite or if you just want a backup for when those services go out and you want to pick up local DTV stations you can build a Gray-Hoverman antenna.
Steps
- In the drawing, the green lines are guidelines and the red lines are the wires.
- Set up the guidelines:
- Establish the center of the board.
- Draw the center horizontal guideline.
- Draw the other 6 horizontal guidelines.
- Draw the center vertical guideline.
- Draw the other 6 vertical guidelines.
- Everywhere a wire and guideline crosses, center punch and drill a small hole (smaller than the screws) through the backboard.
- Put screws in the holes and use the resulting jig for bending the wires making sharp bends and keeping the wire as straight as possible between bends.
- Remove the screws from the backboard and set the wires aside.
- Drill the holes so the screws can pass through them.
- Drill/Cut a hole at the center of the backboard big enough for the BALUN to pass through.
- If the BALUN has screw terminals on the ends of its 300 Ohm wires, cut them off and solder 6” extensions made of stripped Cat 5 or phone wire to the 300 Ohm leads.. Set the modified BALUN aside.
- Glue (3M Spray works well) the foil to the backboard starting at the outer edges. A 20mm gap in the center is OK
- Find the centers of the dowels and drill pilot holes for the screws in one end of each.
- Attach the dowels to the backboard at each of the previously drilled holes.
- Lay one of the wires on top of its support dowels and staple or tack them in place starting at the center. Then the other wire.
- Place the BALUN in the center hole so that the 75 Ohm connector protrudes from the rear of the board about 13mm.
- Silicone or hot glue it in place.
- When the silicone or glue is dry, solder the wires from the BALUN to the center points of the antenna wires on top of the dowels. (Might have to temporarily pull the staple or tack.)
- Connect 75 Ohm cable between Antenna and TV/DTV converter box.
- Mount and aim the antenna.
- A motorized system can be also used to enhance the effectiveness to a great degree. The motor kit and controller are available at Menards.
Tips
- If your TV/Converter has an “Auto Program” function, let it find your stations.
- http://tvfool.com/index.php?option=com_wrapper&Itemid=29
- Find transmitters in your area at:
- It is going to the attic as soon as we get wire and wiring accessories.
- http://www.antennaweb.org/aw/welcome.aspx
- http://www.user.dccnet.com/jonleblanc/Canada_TV_Stations/
- Every station came in with 100% signal strength with no audio or video anomalies with the antenna sitting on the floor in an aluminum sided house.
- In Midtown Memphis, TN, all the transmitters I am interested in are between 65 and 80 degrees from North and range from ~{{safesubst:#invoke:convert|convert}} to over {{safesubst:#invoke:convert|convert}}.
- The Official Home Site of the Gray-Hoverman antenna at http://www.digitalhome.ca/forum/showthread.php?t=81982 features ongoing research and development, so newer designs of it now perform even better than this one
Warnings
- For outdoor use replace the plywood and foil with a mesh reflector using "corn crib" fencing because this design would have too much wind loading for outdoor use
- The Gray-Hoverman antenna was released under the GPLv3 license, which stipulates that the following text must accompany this article:
- The original design for the Gray-Hoverman antenna is at http://www.digitalhome.ca/ota/superantenna/index.htm but their drawing didn't include drilling templates, etc.
- The Gray-Hoverman antenna designs, schematics, and diagrams on this site are Copyright ©2008 and are free: you can redistribute them and/or modify them under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at our option) any later version. These designs, schematics, and diagrams are distributed in the hope that they will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. For your complete copy of the GNU General Public License to go along with the designs, schematics, and diagrams, see www.gnu.org/licenses/gpl.txt
- However, the GPL is being applied erroneously. It does not and cannot protect ideas including the original Hoverman or the newer Gray-Hoverman designs. Thus, one may ignore the word "designs" in the preceding paragraph. Nor do the authors provide the source for their own GPL drawings for anyone to edit. The GPL does not apply to any new drawings of the Gray-Hoverman designs.
- Also, the plywood would come apart after being rained on a few times
Things You'll Need
- Backboard: 3/8” or 1/2” plywood, 31” H X 25” W
- About {{safesubst:#invoke:convert|convert}} of 12-2 Romex or {{safesubst:#invoke:convert|convert}} of #12 solid wire. Insulated or uninsulated is OK.
- 18 dowels, 1/2” dia, 100mm long. Cut from stock as necessary. 3/4” X 3/4” sticks are OK too.
- 18 #6 X 1&1/4” wood screws or drywall screws to hold dowels to backboard.
- 1 300 Ohm/75 Ohm BALUN (<$5.00 at Radio Shack)
- {{safesubst:#invoke:convert|convert}} of 12” wide aluminum foil.
- 6 in of solid Cat 5 or phone wire or other 22 to 24ga solid bare for extending the 300 Ohm leads on the BALUN.
- Silicone or hot melt glue.
- Stapler or upholstery tacks. (the little black ultra-sharp ones
- A drill with assorted small bits
