Dual-Element HDTV Over-the-Air Antenna

This is a compact version of my Quad HDTV Over the Air (OTA) tabletop antenna, it gets great reception in urban and suburban areas and gives a clear HDTV picture when properly aligned. It has a small footprint and works with any small-to-enormous screen high definition smart TV's. It's great for bedroom TV's where space can be at a minimum.

(2) aluminum soda cans

3 feet of RG-6 coaxial cable

10 inches of RG-59 coaxial cable

(2) F-type panel mounted CATV female solder connectors:

https://www.amazon.com/dp/B07W3K6JL7?ref=ppx_pop

(1) right angle coaxial connector:

https://a.co/d/5OdZjJB

(4) RG-59 coaxial connectors, the smaller the better

2-way cable TV splitter:

https://a.co/d/fZk0Juk

5½" x 2-5/8"" x 1/8" plexiglass

3½" x 3/4" x 3/32" plexiglass

4" x 2½" x 3/8" acrylic block

(1) 3/8" x 3" bolt, washer, lockwasher, and nut

(2) 6-32 x 3/4" pan head screws

(2) 6-32 x 3/8" pan head screws

¼" heat shrink tubing

(4) stick-on rubber feet

Begin with the empty soda cans. Using a utility knife, use caution and carefully cut off the entire bottom of the cans, about 1/2" up from the bottom. Then drill a 3/8" hole in the dead center of the bottom of each can, being careful as the aluminum is thin. Start with a few progressively larger pilot holes first before using the larger bit--a step-drill bit works well for this.

Insert a 3/8" bolt through the hole on the concave side and tightly secure with a washer, lock washer, and nut on the other side. Now insert the bolt into a drill press and while spinning on the lowest speed, gently press the can bottom onto a sheet of coarse sandpaper (I used 24 grit) to begin grinding away the aluminum bottom. This will leave a perfectly round parabolic shape when through. Repeat for the other remaining can. Alternatively, you can grind off the can bottoms by hand using a circular motion on the sandpaper, but it will take a bit longer. You should now have 2 parabolic-shaped reflectors for the antenna.

Cut the RG-6 coaxial cable into two 18" lengths. Using a hobby knife or a coax cable stripper, carefully remove the outer sheath, silver braid, and white inner core insulation, exposing the inner conductor wire. This is a copper-clad steel wire that is stiff and takes some effort to bend.

Using a 7/32" diameter rod or a #2 phillips screwdriver shaft in a vise, slowly wind 20 turns of the wire around the rod keeping the windings close together. Slide the coil off the rod and holding with pliers on each end, gently stretch the coil to 7 cm long. Straighten 3/8" of the wire in from each end of the coil, bend it inward toward the center, then straighten it even with the axis of the coil. Repeat this for the other remaining length of coax cable, making 2 coils total.

The mount consists of 2 pieces of plexiglass, one large and on small. I used plexiglass to give it a nice clean look, but any material with the same dimensions can be used.

On the smaller rectangular piece, drill two 3/8" holes 5/8" in from each end and centered--start with a few progressively larger pilot holes first before using the larger bit or the plexiglass will break into many pieces. Then drill two 9/64" holes 1/2" apart on either side of the center of the rectangle.

For the larger vertical mount, I used 1/8" plexiglass as it has to support the weight of the antennas and splitter. Two matching 9/64" holes are drilled in the upper neck 1/2" apart and 3/8" from the top. These holes will match the holes of the smaller rectangular piece. Midway down and centered on the plexiglass, place the 2-way splitter and mark the screw mounting holes where it will go. Then drill two 9/64" holes for it to mount.

On the acrylic base, I used a 1/8" router bit to make a 1/8" deep groove the width of the large plexiglass (2-5/8") so that it could slip into the groove and be cemented in place.

Insert the connector/coil assemblies through the reflectors and mount them to the small rectangular plexiglass through the 3/8" holes, securing them with the locknut. Mount the small plexiglass asm to the larger piece by lining up the holes and securing it with two 3/8" x 6-32 screws, washers and nuts. Then solder one end of each coil to the lug on the female coax connector on each reflector.

Mount the 2-way splitter to the plexiglass and secure with 3/4" x 6-32 screws and nuts. Slip the large plexiglass into the groove cut in the acrylic base and secure in place with plastic cement.

Attach a stick-on rubber foot to each corner on the underside of the base.

I used older RG-59 coaxial cable for this step because it is smaller in diameter than the RG-6 and much more flexible. Even so, I still had to remove the outer cover to get it to bend enough to bridge the gap between the reflectors and the 2-way splitter.

Cut 2 lengths of cable that are longer than the distance between the antennas and splitter (about 4 inches), leaving enough to form loops to keep the connections straight. Then using a hobby knife, carefully slice the entire length of the cables and remove the outer covering only--leaving the copper braid intact. Strip the ends of each length and install a small RG-59 coax connector. These connectors are hard to come by anymore, but I scrounged up several from some old cables that I had. Instead of crimping the braids to the connector with a collar, I soldered them to the back side of the connectors and covered with a short length of heat-shrink tubing. Screw one end of each cable onto a reflector. Before connecting the other end, perform a continuity check between the coil and center conductor, and shield-to-reflector on each cable. You should have continuity on both, and an open (no short) existing between the center conductor and shield. Screw the ends onto the inputs of the splitter. Once all cables are connected, lightly tighten them down with a 7/16" wrench.

Attach the right angle, 90-degree connector to the input of the splitter, which is facing downward. This will make it easier to connect the cable coming from the television.

Connect a length of coax cable from the CATV antenna input on a smart TV to the right angle input of the 2-way splitter.

Download the RCA Signal Finder app to your phone and quickly setup by entering your zip code or current location, then select the networks you want to receive. The antenna is very directional and this app is helpful in aligning it to the television broadcast tower nearest your location. By placing the bottom of your phone flat against the front base of the antenna you can easily align it to the active broadcast towers shown in the app.

Once you have it properly aligned, set your smart TV to receive over the air channels and give it a few minutes to program.