How to build a DB8 Antenna


Common Compact DB8 AntennaYou may have noticed that this site has two DB8 Antenna Designs.  We have the common DB8 on this page, and we also have the DB4 and DB16 versions available for that design, but we also have an optimized DB8.  The optimized DB8 is better on paper for the channels that HDTV use these days, channels 14-51.  It is also a beast, and would not fit in my attic, so I trimmed it up and made a DB16.  The common designs available elsewhere on the internet generally lack detail or are incorrectly wired.

Basically, a DB8 antenna is made up of two Db4 antenna’s “ganged” together in a proper way.  A DB8 will pick up stations as far as 60 miles away in good conditions.  Before you do your build check out the tools on this page to see how many stations you might get and how far away they are. There are similarly designed professionally made ones available to buy; DB8 Multidirectional HDTV Antenna and the DB4 Multi-Directional HDTV Antenna. At the time of this writing they were not bad at $60 and $50, respectively. You could build the DB8 below with junk lying around your house or you could spend about $15 on all new materials for a strong and durable outdoor installation.

Materials

  • 29′ 8 to 14 gauge Solid Copper Wire or ~11′ of Romex – Yes, you may use coat hangers
    • Remove any insulation
    • Cut sixteen 14″ Sections, four 19″sections, and two 24″ sections
  • 43″ 1×3 or similar Wood
    • Look for dirt cheap scrap wood if on a budget
  • 22 1” Screws
  • 22 Regular or Lock Washers
  • 1 Balun (Available at Amazon($2.99 + FSSS), RadioShack, or your neighbors/parents garage)
 
*For an outdoor installation, see here

Step by Step

Step 1: Paint the wood with an oil based sealer if you are mounting your antenna outdoors or if looks matter to you.

Step 2: Cut the wire into sixteen 14″ strips, four 19″ strips, and two 24″ strips and straighten them. A drill and pliers come in handy here, watch the video.

Step 3: Form the whiskers using the sixteen 14″ strips. Bend the whiskers at the halfway point and leave 3” of space between the ends. From the bend to the end of each whisker should be 7″.

Step 4: Mark where the screws go (black dots) according to the diagrams on this page. Place two sets of marks centered on your wood 1 1/4” apart by running your tape measure lengthwise down the wood and marking at 3”, 8 1/4”, 10 7/8”, 13 1/2”, 18 3/4”, 24”, 29 1/4”, 31 7/8”, 34 1/2”, and 39 3/4”. Drill pilot holes unless you’re feeling lucky. For the red dots(at 10 7/8” and 31 7/8”), drill a hole large enough to fit your gauge of wire through.

Compact DB8 Antenna Hole Marks

Step 5: Put your screws with washers into the holes and tighten them until they have ½” remaining.

Step 6: Place your whiskers into place

Step 7: Criss cross the 19″ lines into place bending as needed according to the picture at the top of the post. You’ll need to add some electrical tape to insulate the lines where they cross. This in essence, creates two DB4 Antenna’s, one on top of the other.

Step 8: Tighten the screws down to hold the whiskers and 19″ transmission lines in place.

Step 9: With the remaining two 24″ strips we will connect or “gang” the two antennas together.  Feed one strip into the back of the antenna through the left red holes and the other one through the right  red holes.

Step 10: Loop the strips around the 19″ lines were they come out of the red holes.  Try to be as centered as you can

Step 11: Put your balun on the back of you antenna attached at the midpoint of the two 24″ lines.  One lead on the strip connecting the left 19″ strips and one lead on the strip connecting the right 19″ strips.

Step 12: Make sure you’re bowties are still 3” apart and then plug in the antenna to your television!

Step 13: Test where you get the best reception. Location is everything, even a few inches can make a huge difference. Elevation also generally better, but keep in mind that attics cut about 40% of your signal. Many televisions have a signal strength meter that might help you find a good location.

  • For More range – Add a reflector(Article coming soon, place the reflector 4 inches behind the bowties)

Leave a Reply