Introduction: Simple OTA HD TV Antenna - Near Zero Cost - Mostly Scrap Materials
Like a lot of folks, I do not love my cable company. A lot of our "entertainment" is streamed over Internet, so when OTA - over the air - HD broadcasts became the norm, I decided to see if I could get sufficient signal with an Antenna. There are a several ways to find out if this is an option for you. One, does it work for any neighbors? Two, check out the TV Fool website -
http://www.tvfool.com - this will tell you what signals you can expect at your address, how strong those signals might be, and where those signals are coming from (direction). And of course Three, try it.
TV Fool made a pretty good case for my address, and a bit of reading made me believe I could compete with commercial antennas using a home built version.
The following instructable is a collage of builds I found online , and intended to be nearly free to construct.
Step 1: The Basic Antenna - Quick to Build, Suitable for Tests.
Following the drawing picture, mark intersections on a scrap of wood.
I used a piece of oak flooring about 50cm long.
Drill holes for screws at each of these intersections
Cut 8 pieces of metal coat hanger 350mm long
Bend each of these into the V shapes as shown in the diagram
Remove paint at the tip of the V to allow electrical contact to red and purple lines.
Using wire, or bits of hanger or anything conductive as the red and purple path, assemble antenna. Make sure red and purple leads to not touch each other, but do touch the hangers at the washers – if using bare wire insulate points where red and purple lines cross. Attach the V shapes with screws and washers. Pennies make a very cheap washer... they only cost, well, a penny:)
Add the “Balun”, aka “Matching Transformer” , About $0.50… if you don’t already have one… Input receptacles: 2 x spade terminal, Impedance: 75 / 300 ohm, Bandwidth: 5MHz - 900MHz UHF-VHF-FM
Connect coax to TV or if connecting to entire house with splitters and such, I recommend an inline amplifier between antenna and first splitter.
My test verified I was able to get HD channels, but one of the networks was missing... I was hoping I could overcome this with antenna placement. (next step)
Step 2: Placement and Reflector
My reading indicated that for my address, ideal placement would be well above house. I wanted to avoid this if possible as my scrap wood antenna wasn't really designed to weather nicely. I decided to add a reflector, which my reading indicated would boost my signal measurably.
I cut four pieces of scrap 2x4 about 3' long. On two of these I tapered the outside 1' from full width to .5 width. I ripped one of the 2x4s in half ( two 2x2s). I assembled these, the tapered pieces forming the top and bottom, and the other three boards forming three legs. I stapled hardware cloth ( my biggest purchase of the project) to the back of the reflector, and attached my antenna to the front of the 2x4. see drawing and pictures.
TV Fool told me that the the stations that I could receive were coming from my North West. I placed the assembled structure in my attic ( disclosure, I assembled it in my attic as the opening was less than 3' wide ). I pointed it roughly North West and attached a cable running down to my distribution point.
All is good, and I actually receive more channels than I did with my basic cable package. I do have the occasional artifact and skip in signal, especially during hard rain. I could probably overcome this with a tower,,, but this was easy, quick, and cheap.
*Update* - I started getting very inconsistent signal on the weaker channels. i.e. Channel 10.1 would work great sometimes, and not at all other times. To the best of my knowledge nothing had changed. Lacking a good real time signal meter, I set the TV on 10.1 and set it where i could hear it. I went into the attic. I rotated the antenna about 5deg North and 10.1 stopped working. I rotated it back, and it started again. I was just at the edge of the usable signal. I went back to TV Fool and pulled a picture of the map with my signal location. I printed a google earth view of house, I drew a lines and measured to see that the signal was ~ 32deg from my house alignment. My antenna had been at about 22deg. I set it close to the 32deg target, and all is good again. I must have bumped the antenna on some earlier attic journey. The moral of the story is direction is important on this antenna. Take your time and get the antenna pointed toward your signal.