Nathan Cohen made this discovery after listening to a Mandelbrot talk on fractals: http://en.wikipedia.org/wiki/Fractal_antenna#Fractal_element...
He's the reason you don't have a stubby antenna sticking out of your cell phone anymore. Really cool story.
Surprisingly he does not have a wikipedia article. You'd think someone who made such an important discovery would have a rather long one.
1. What exactly is the purpose of the cardboard tube? I'm guessing the key point is that it's non-conductive, but would the same coil work without the cardboard? (not very knowledgable about antennae I admit)
2. How the hell does that connector even work? It looks so marvelously out of place ... does this mean the wire mesh around the normal coaxial cables is just shielding and doesn't actually do anything? If so, how come you don't need shielding?
Those were the two main questions that popped to mind, obviously I don't know anything about this stuff and I could probably look it up somewhere. But maybe someone here can provide a human-to-human good enough explanation.
PS: I once noticed my Sega genesis was producing a vary fuzzy picture, so I went to fiddle with the cable and noticed it was not even plugged in. At the time I really freaked out and to this day I still wish I had a picture.
Back in college, we were watching a, umm, adult video on my roommate's VCR. The guy from the room next door walked past, and said "oh, you're watching the movie too?". It turns out that we'd mistakenly connected the VCR's RF output to the antenna, so the guy next door was watching our transmitted movie. (although his picture was poor)
Sticking up almost any wire more than a few wavelengths long will collect a reasonable amount of a strong signal. A truly resonant antenna for the frequency you're interested is a lot better, but not that helpful for general HDTV viewing where the frequencies range all over VHF and UHF.
One of the amazing things I've learned from years of ham radio is how many unseen and unpredictable things affect radio signals. You can move your antenna twelve inches to the left and lose a signal completely, especially inside a structure. Or an airplane flying overhead can reflect enough "multipath" signal to wreck your TV viewing for 30 seconds. Of course your own body blocks a lot of signal and is capacitively coupled to the antenna system as you adjust it. So if you're playing with an HDTV antenna and are too young to remember the fun of constantly adjusting TV rabbit ears, just keep tweaking until you get a good signal.
Too young, ha! I use rabbit ears on my HDTV (no cable, just netflix + locals is enough for me) and laugh when I go to Best Buy and see "state of the art high definition" antennas for anywhere from $20 to $100. The same laugh hits me when I go down the gold plated monster cable isle, but that's a different story.
It's an interesting pricing model, and the $20-$60 cables more than paid for themselves after a single tour. Probably not appropriate for casual use though.
Like with the cables, neither makes sense. I could just buy one cheap cable from a reputable brand and probably not need another for 30 years.
And if I do? I'll just buy another. Because they're cheap and work perfectly.
And I know what I'm doing next time I'm at the mall.
Is he doing it right? Should the cables fail after every show? Shouldn't he just get better cables?
2. The shielding is there to keep signal interference out, which is useful if you have a clean source to start with (ie: Cable TV or a properly designed antenna). In my case, I just wanted to pick up as much signal as possible, and this is what I had to work with.
2. It's not shielded because the entire thing is the antenna. I guess he could shield it between the TV and the actual wrapped tube part but this is sow low-tech it wouldn't make a difference. Your standard roof mounted antenna is shielded between the antenna and the tv because you don't want interference between the two points.
To clarify this, with a roof mounted antenna the wire needs shielding because it is typically running down the middle of the house and thus would be subject to interference from the many electronic devices therein.
With this guy's solution, the wire just runs out of his window, and therefore as long as he doesn't have any ageing analogue equipment (speakers, cordless phones etc) near his TV or his window the issue of interference is minimal.
I'd be interested to know the strength of the signals you're able to receive with your paper-towel-tube antenna design.
The coathanger antenna works best for me though, I'm too far away from most stations for just a wire.
Your design might work best for VHF stations while the coathanger method is best for UHF
Canada still has analog stations?
I had to strip a coaxe cable with a pair of scissors and my hands. That took at least 20 mins.
But here we are
I have to remember to take that down before someone gets cut in half running down the stairs
If you search a little more through the http://www.digitalhome.ca/ forums, you can find newer generations of the design. Various folks have been using genetic algorithms to find more efficient modifications to the original design. http://www.digitalhome.ca/forum/showthread.php?t=119489
Using your antenna, how could I go about amplifying the reach in an attempt to pick up more channels and/or increase the display quality of current channels?
Depends on your location, of course, but the most effective thing I could do is get out of this valley. Next, I'd straighten the antenna wire and move the antenna outdoors (with a 75Ω coax line connecting it to the TV). You could also adjust the length so it's resonant at a particular frequency, but that will weaken the signal you receive on other channels. Alternatively, cutting it way longer than the minimum resonant length (like an order of magnitude or so) seems to make for a pretty forgiving frequency response. Then again, commercial broadcast transmitters are probably running enough output power that unobstructed line of sight makes more of a difference than anything else can.
I use a matching-transformer to connect it to the coax plug.
I like the simplicity and potential of your design though. I want to try an array of tubes and wiring, and see how well that works.
Tried some shielding on the back and it did not make any difference.
I can get all the stations possible in my area with just 2-bay.
So build with 2-bay first and test maybe to save time/money.
I also did not need the reflector, in fact it made things worse.
For me it's ivi.tv
1) Attach 75-foot wire to TV
2) Attach other end to weather balloon
3) Inflate balloon
4) Watch Jeopardy
Note: there are probably many other reasons why you shouldn't do this. Make sure to let us know when you find out what they are.
It's my strong opinion that everything here is ethically sound. This sort of "hacker" culture is the meat and potatoes of what drives innovation in the United States today, and whether this specific incident results in a new product or simply higher security by cable providers, progress has been made.
He built his own antenna to receive local channels that are broadcast over the air. These are broadcast specifically so that people with antennas can receive them.