Eight Simple Steps to Build a Homemade UHF Antenna
1. Pick a small plywood piece (or other weather resistant or weather impervious material) - say 30x16 inches in size, and some grates from an old oven or a couple of metal drying racks.
2. Wrap the piece with the aluminum foil type of high temperature duct tape.
3. Now, cut a 2 X 4 to the proper length and prepare a notch cut in the bottom (so as to be able to mount it in the rotor or on the mast). For instance if your board is 30x16, you may want to keep a 5 inch notch cut.
4. Lay down the 2 X 4, lay the board face down on top of it and center it, and nail it in with some roofing nails.
5. Next, you need to figure out the place for bowties, and then the matching transformer needs to be connected at the center.
6. Grab a few screws and washers, and four coat hangers. It’s time to get rid of the head of these hangers and cut the base to form couple of V-sections from each of them.
Moving on, you need to trim these 8 V-sections in such a way that their legs are about 7 inches long, and then polish or roughen the elbows of these V sections with sand paper just where they make contact with the washer.
7. You need to find more coat hangers, or probably anything stiff that can do the trick. Having done that, it’s time to put your V sections under each washer, with the wire.
Next, tighten the screw, but before that you may want to ensure that your wires and V's have same length so as to create the right phasing. More so, the wires will crisscross on the ends, but you’ll have to keep at least one of them insulated.
8. Finally, you’re good to go ahead and connect your matching transformer in the middle, and check that the Vs are parallel with the foil background and placed uniformly.
Now, it’s time to bid a happy goodbye to all the age old crappy antennas that you’ve (if any) and install your latest DIY creation.
Note: This antenna is expected to work well with UHF frequencies, and you can't expect it to catch the weakest VHF channels for sure.