With high cable/satelite TV provider prices, the expansion in availability of high speed internet, and those just wanting to cut monthly expenses, "cord cutting" has become popular recently. Many people simply watch Netflix or Hulu via high speed internet, but it's nice to have another option. Afterall the TV signal is free for the taking! Building your own HDTV antenna can not only save you some money and help you watch free TV channels, it can also be a really good project for any ham that likes to build antennas; with little modification this antenna could be used as a recieve only on many frequencies.
First, I would like to give credit to this website, as I found it the most useful in learning how to construct my own. I encourage all to read it, and even if you do not wish to purchase a kit, maybe hit the donate button. These antennas can be constructed from ordinary items, that a person may have just laying around the house. Even if you have to buy something, it shouldn't amount to more than 10-15 dollars.
Before we talk about HDTV, we need a quick history lesson. Traditional analog TV signals weren't very efficient, occupying about 6 mhz of bandwith and a picture quality that was 704 x 480 pixels. Channels 2-6 appear in the "lower" VHF band which spans 54-88 mhz, channels 7-13 are considered High VHF and go from 174-216 mhz. The UHF TV spectrum is from 470-890 mhz and the remaining channels 14-83 live there. HDTV takes advantage of many technologies such as multiplexing, to transmit more data in the same 6 mhz bandwith. The main difference, is that HDTV channels can have a resolution of 1920 x 1080 pixels. Viewers may also experience other features as well, such as multiple channels in place of a single one. For example, where there was a single "Channel 14" on analog, there may now be a 14.1, 14.2, and 14.3. One thing to consider when building a HDTV antenna is that the channel displayed by the TV set may not correspond to where the actual frequency is. The last analog TV broadcast was in June of 2009 in the U.S., and some TV stations also changed frequencies at that time. To keep from confusing viewers, many stations broadcast an identifier on the new frequency, the TV simply keeps "showing" the new frequency on the same channel. In other words, you should check to see what actual frequency the stations are in your area. Your channel "6", could actually be in the UHF band instead of the lower VHF as you would expect.
The first thing I suggest, is to visit TV Fool's Website to gather some information about TV signals in general, and the stations in your area. Click on the link circled below, they have a great intuitive map that is an invaluable reference.
Next type in your address.
Now, a list of TV stations and other relative information is generated. I would encourage anyone reading this, to click on the signal analysis link on that page, there is some good information there. The stations with very strong signal, will be easy for you to tune, so concentrate on building an antenna that will have the best performance on the frequencies that will have the lowest signal strength, that you can reasonably tune in. Remeber to factor in losses, such as coaxial cable runs, and signal boosters.
If you look to the left of the page once you've loaded the channel list for your area, you will see something like this image below. You can print this out, and cut it out. With a compass it may help you to aim your antenna, at least a "rough aim". Here in north central AR I aimed my antenna toward Chenal Mountain and had pretty good sucess. You must remember to scan for channels each time you aim your antenna. If you skip that, your TV won't be able to recognize any new channels. I know it's kind of a pain because a lot of TVs take several minutes to perform this, just be patient. The antenna can be quite senstive to aiming, just a small movment can make a pretty big difference.
Here is a video that I took using the antenna in the photo at the top of the page.