Here's my home built digital TV antenna. Most of the parts I had laying around, so the only item I had to purchase was the antenna transformer, for roughly $5.00.
The basic design came from the Popular Mechanics website, but I wanted to add something a little more to it so it would stand up to the elements outside.
It is currently mounted to the side of the Garage, and I am able to tune in about 20 local digital TV channels with it.
Step 1: Create Antenna Housing
Start with a piece of Schedule 40 PVC Pipe, 25" long. Cut it in half lengthwise 16".
Step 2: Assembly Board
Rip 1/2" off the edge of a 48" Long 2" X 4" board. This should fit into the PVC as shown in the pic.
Step 3: Lay Out Antenna Positions
Lay out six fender washers evenly spaced to allow for 3 antennas per side, keeping the edge of the washers inside the edge of the board.
Step 4: Prepare the Wires
Cut 6 # 12 bare copper wires 16" long and bend them into "V" shapes for the antenna array. Cut 2 #12 bare copper wires 16" long for the phase wires.
Step 5: Cut Slots for the Array
Mark and cut slots in the top half of the PVC at the locations where the antenna wires will protrude.
Step 6: Make the Cable Hole
Mark and drill a 1/2" hole near the bottom edge of the PVC for the TV Cable to connect to the antenna.
Step 7: Assemble the Array
Attach "V" shape wires and phase wires under fender washers as shown in the pics. Make sure to insulate the phase wires where they overlap so they do not make contact with each other.
Step 8: Attach the Transformer
Attach the transformer to each phase wire as shown in the pic.
Step 9: Assemble in the Housing
Slide cable through the hole, up to the slot where the PVC is cut in half. Slide the board with the array into the PVC until you can connect the cable to the transformer. Then continue to slide the board assembly into the PVC until the board is flush with the end of the pipe.
Step 10: Fit the Pipe Halves Together
Place the top half of the PVC pipe over the board assembly, making sure all the antenna wires are in the slots.
Step 11: Cap and Tape
Put a 1 1/2" PVC end cap on, and wrap the entire pipe with electrical tape. (The tape serves 2 functions...it holds the whole thing together, and it adds a bit of a sinister look to it).