I made a UHF antenna for digital TV reception

Sat. Jan. 10, 2009

I followed these instructions to build a UHF antenna. I left the reflector out because it seems to work better for me without it.

It’s made from 6 coat hangers, a two by four, 8 screws, 16 washers, and a “balun” (a few dollars at Radio Shack) which is a 300-ohm to 75-ohm transformer which matches the impedance of the antenna to the impedance of the co-ax cable and transforms the balanced antenna signal to the unbalanced coax signal.

it’s still not great, but it’s a lot better than what my previous antenna was able to do with the digital signal.

I still get occasional dropouts, and the PBS station doesn’t come in very well at all (it is VHF though, so that is understandable. I wish they’d broadcast on UHF, as every other channel in my area does, so I’d only need a single antenna, and PBS is one of the channels I watch the most — not that I watch TV very much at all these days. At least all the transmitters are in the same antenna farm, so I only have to point my antenna in one direction to attempt to get all the stations I might be able to get.

In general, I’m not very happy with the digital TV situation though. Unlike analog TV, when reception is marginal, the channel becomes unwatchable — it either works perfectly, or it might as well not exist. There are other things I dislike about it, but these may be more problems with my particular digital converter box (a Magnavox) than anything else.

  • The size of the image shifts around from channel to channel, and even on the same channel. Sometimes it’s letterbox, sometimes is regular TV aspect ratio, but has black bars on all four sides, sometimes it’s regular TV aspect ratio, and fills the whole screen. There are options on the converter box to display things in different ways, “letterbox”, “full”, “zoom” etc. which transform the image in various ways, however, the means to set this is very cumbersome, requiring stepping through several menus and probably 10 button presses altogether. And it’s a single global setting. There should be a way to tell the box, “whenever you see this kind of signal, transform it this way, whenever you see that kind of signal, transform it that way.” But know, it’s completely brain dead, and there isn’t even a single button which just toggles through the available transformations, you have to dig through an idiotic menu system. Ugh. I freakin’ hate that shit. I would like to see Steve Jobs, “Mr. Design” talk to (scream at) the guy who designed this thing and its idiotic remote control.
  • Also, what’s the deal with the freakin decimal point in the channel numbers? What freakin’ purpose does it serve other than to be an extra button to have to push when you’re changing channels. I have channesl 2.1, 2.2, 2.3 — why not just 21, 22, 23? I have channels 13.1, 13.2, 13.3 — why not just 131, 132, 133? What purpose does the decimal point serve?
  • And speaking of changing channels, why is it so slow? It takes forever just to cycle past the channels that I hate. Changing channels on analog TV is far faster. And what’s with the gigantic overlay that pops up every time you change channels and takes forever to go away — I guess it’s designed for slow readers.
  • And speaking of channels that I hate, I have 14.1, 14.2, 14.3, 14.4, 14.5 — all religious channels. What the fuck?
  • And then there’s the audio. For some reason, the audio level coming out of the converter box is very low, and I have to turn up the TV volume very loud just to hear it at a normal volume. This means there’s this low level hiss of noise in the background of everything, and there is no such thing as silence.

So, so far, the over the air digital TV guys have just plain flunked. Analog TV is far superior so far as I can tell.

~ by scaryreasoner on January 11, 2009.

6 Responses to “I made a UHF antenna for digital TV reception”

  1. It sounds like you definitely have a converter box that is not performing up to specifications or is in need of repair. All boxes are not the same in displaying aspect ratios properly. The Zinwell brand converter is very highly rated in this regard. The ideal spacing for the reflector is about 5 inches from the bowtie elements and not 4 inches. You may want to add a UHF amplifier at the antenna also.

    The decimal point is needed because each channel now contains up to three telecasts, the digital mode is more compact. Changing channels is not slow for me and there is no overlay unless I call it up. So the brand you have should be avoided. It is not the TV stations doing that.

    As far as the religious channels go I can’t tell you how to fix that, except to pray for better programming. And leave the four-letter words out of the prayers or the Lord may strike you down.

    The audio levels should be adjustable in the converter box, find the menu item to do that and adjust it to maximum and use your TV to control volume.

    The digital format adopted was the worse of the two which were considered. The picture is of very high quality with a decent signal to the TV and is better than those small satellite dishes provide. When the switchover is complete there may be better programming on the air too.

    I would recommend that those who seek an antenna do some research and get a good commercial one with an amplifier if they are any distance from the transmitter. Those homemade ones are a compromise and have no specifications to look at, and the stated construction materials are not up to par.

    The digital mode has high quality stereo sound too. Happy viewing.

  2. I tried all kinds of things with the reflector. The best results for me were had with no reflector. All my source signals are from one place, due south… not much need to reject signals from the back side.

    Also, I’m in Houston, the fourth largest city in the U.S. after New York, L.A., and Chicago. If I’m having trouble getting decent signals where I am, the people in the sticks are just fucking fucked.

    The antenna is basically a clone of a channel master 4221.

    I agree that the audio levels should be adjustable at the converter box. However,there definitely NO WAY to adjust the audio level on the converter box, despite the fact that an ideal world, there should be. It’s a bona fide piece of shit.

    Your “explanation” of the need for a decimal point reveals a basic failure to understand my complaint. The decimal point is not needed. Your explanation is made of fail.

    As far as profanity, I say, fucking fuck yes.

    “When the switchover is complete there may be better programming on the air too.”

    Your optimism is remarkable.

    I never said it was the broadcasters making channel changing slow. Of course it’s not, they all broadcast simultaneously, all the time. Of course it’s my piece of shit converter box. You state the obvious.

  3. I made one of these for my downstairs analog set to use with a Zenith converter box (I looked at the Magnavox box at Walmart and it looked like junk — the Zenith box is awesome, and I recommend it). This antenna performs fine 55 miles away from NYC transmitters during the winter viewing season. When the trees to the south leaf out in the spring I will loose almost everything, so an antenna outside and high up is in order.

    Re: slow digital channel changing – it’s true. When watching analog tv through the analog passthrough the channels change very quickly. On digital viewing there feels like theirs an unnecessarily long delay.

    All digital tuners are not created equal. I noticed on our digital set upstairs (a Sanyo) that the on screen programming directory will just state the name of the program (sometimes it just states ‘DIGITAL CHANNEL 4’ with no programming notes. The Zenith converter box gives you a nice detailed description of the program or a story synopsis. A DVR unit I bought with a digital tuner also has the full channel programming info, PLUS you can toggle ahead to see what is coming on in the next hour. They should ALL have that feature – it is digital, after all, and it must only be a matter of encoding that function on the chipset of the unit.

  4. OK I live in back woods Alabama, where before June 12th I recieved 11 channels. I have not seen a tv show since that time. I dont even know if there is a tornado comming at me as I cant even get a news broadcast. NO TV digital sux, I would much rather watch ablurry station and know I was getting readyt to be blown away than where I am now. I have bought every antenna that Wal-mart has to offer and NOTHING. Radio shack is a 30 minute drive in any direction. My question is now that there has been a complete conversion to this new crap, does your antenna still work that you made?

  5. It works better than nothing. My dad made an antenna just like mine, and for him, it works perfectly. He had gone to radio shack looking for antennas, and got nothing that worked half as well as this. I think it kind of depends on where you are, where the broadcasting antennas are, etc. This antenna design is pretty directional, which means you should find out where the broadcasting antennas are, so you can kind of aim the antenna at them. Getting the antenna up high, and free from obstructions helps (this is where for me, so far, not so good.)

    But, it’s definitely worth a try, as it’s very cheap to make, and not difficult, and likely to be at least as good as the typical radio shack crap, probably better. Give it a shot. Worst case, it doesn’t work, and you’re out 5 bucks and a bit of time.

  6. I totally disagree with “Roy.” We have three of these boxes, from 3 different manufacturers. Digital television does not work. We’re in an urban area, 4 miles from the main transmitter and in the middle of its directional pattern, and the dropouts are unacceptable. We are also Netflix users, so I’m about to convert our bedroom TV to a Roku box and give up on network television. Comcast has a lock on cable in our area and I’m not paying $99/month for television, cable or otherwise. Local news is gibberish, I refuse to pay to watch commercials, so the options are give it up and get the time back.

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