Instructables

Build a DIY Recycled Antenna (To Get Free T.V!)

Due to all of the recent talk about the "DTV Switch-Over", T.V. has been something that is on my mind. I recently scrounged a perfectly good T.V. on trash day. It still amazes me that people will throw stuff like this out.

Anyway, since I got the T.V. I've been experimenting with different ways to get signal. At first I was tempted to try to run a cable wire up from the basement at my house. My parents ruled that out. Then I tried using a paper clip in the antenna in spot on the T.V. That gave too weak of a signal.

That led me to build what my dad has dubbed the "Cantenna." It's all from materials that I got in my recycling bin or took from old projects. If I can find this stuff, you can too.

This is great because now I have free and easy T.V. that I pay absolutely nothing for (except electricity).

NOTE: I'd like to apologize. Image notes aren't working for some reason. If you're having trouble with anything, just leave a comment.

Step 1: Deciding on an Antenna

NOTE: YOU CAN SKIP THIS STEP UNLESS YOU'RE INTERESTED IN THE SCIENCE BEHIND THE ANTENNA. YOU CAN BUILD THE PROJECT JUST FINE WITHOUT KNOWING THIS.

Seriously. This step will probably bore most people away from the project. If you aren't interested, just skip it!

When the paper clip wasn't working as an antenna for my T.V., I seriously was thinking about going out and buying a real antenna. Then I decided I would really try hard to be green. So I hit the interwebs and started googling. I found out that one of the best types of antenna for my purpose would be a "Dipole antenna." According to wikipedia (here), "These antennas are the simplest practical antennas from a theoretical point of view." Simple is always good. I won't get into all of the details here because that's what wikipedia is for.

So, I did some more googling and discovered that I could skip all of the calculations on wikipedia, and basically just hang up two halves of the same can.

Well, if you survived that you can continue to the next step now.

*Note: Image taken from wikipedia and used under Fair Use (It has a GNU free documentation license so I think that's okay).
 
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billbillt1 year ago
great
stovetop361 year ago
Thanks for an awesome project. Easy to make and works just as well as a 30$ commercial product I bought for another TV. I also made one of these for use on a stereo receiver that had a coaxial hook for FM radio. Works awesome as an FM radio antenna as well. Thanks again for saving me at least 50% :-p
Minifig6665 years ago
 Nice Instructable. I'd like to point out if you are in the U.K. and are and not paying a TV Licence then this is illegal.
License to get FREE AIR TV..???? REALLY? How come this doesen't sound right for this to happen. (?) Well....if a TV Broadcaster sends the signal in FREE AIR than How or Why can any Government say a person must have a License? So......if you are on your laptop getting WiFi in some location with out breaking the Security Password will that Government say you need a License? Society has changed so much that soon it will be "If you wish to breath.....pay the tax and the Government will give you air"
Even if you are getting TV on the net! If you have machinery for the purpose of getting you transmitted content (any standard TV can) then you (your household) must pay the tax. This is because the BBC and all major masts are funded by the government through this tax. You even have to pay the tax for 'Freeveiw'! Scandalous...
http://en.wikipedia.org/wiki/TV_licence#United_Kingdom
The lucky people of north America have never had to pay a TV licence, more scandals!
One of the reasons Americans do not have to pay for Free Air TV is due to the fact that commercials support the program. Years ago, when all we had were antennas , lucky to get 3 channels too, we did not have to PAY for TV. free Air is just that.......any signal not secured or blocked by the sender is capable of being viewed, listened, or monitored by any person whom may receive it. Like WiFi signal carrying internet, if not secured it is Free Air. Like I have been at location to get WiFi like - Police Stations, library's , schools, neighborhoods, and so on. As long as the user does not infringe against any laws or break a secure setting than the general public may access - (may not alter in any way and the signal must accept other interference -) it according to the Federal Communications. Well....at least for now TV that is Free Air is FREE until our great government wishes to impose another TAX or FEE or LAW or something to take another thing away from The People of our Nation. Sorry......in-depth.......guess may have gotten a bit carried away.
There's nothing wrong with the TV license laws; if you don't want to watch broadcast television, then you don't have to pay it, just remove any antenna from your house so you can prove that you don't use the signal. In return for £130 a year (that's about $210 at today's exchange rates) we get many channels of advert-free high quality television, good, balanced news coverage, etc. How much do you pay a year for your TV in America? And as I understand it even though you pay for it, pretty much all the channels have adverts.

Assuming the US channels apart from the 24-hour news ones have the same advert timing as sky (the only ad-supported channel I've ever watched a large amount of), that's 8 hours of adverts per day per channel. So you pay whatever your subscription fee is for however many channels broadcasting 16 hours of repeatedly interrupted content a day.
We pay $210 a year for 9 advert free TV channels, 11 advert free radio channels, plus another 38 TV and 13 radio channels that use the same broadcasting systems.

I'd say we get a pretty good deal.
It's a very good deal. In the USA many peoples pay about $100 (the minimum) per month to watch commercials.
odd law, as canada has the same with CBC. but we dont have the tax and the government owns the CBC
chill out. the reason one's taxes in the uk include tv license is because over there the programming is quality and there are a lot more educational, commercial free or low-commercial programming one can actually learn from.
msw100 spa31rky3 years ago
you need a licence in the uk even if you watch tv on a laptop
need a licence to go to the toilet soon
the Watcher5 years ago
Solder does not stick to aluminium
It does if well cleaned and you use flux
Gjdj3 (author)  the Watcher5 years ago
Haha, idk then. For some reason it worked for me. Thats interesting... Any ideas on why it worked for me?
Dr. dB Gjdj34 years ago
Love this project - it has such a great "ET-phone-home" feel to it!

Now, to address your question:

Although solder won't actually "wet" to aluminum, your "cross-hatching" trick, with gouges in going in many different directions, will have created enough opposing "hills and valleys" for the molten solder to "grip" the roughened spots - sort of - similar to the way "scarifying" or "etching" glossy surfaces will improve the adhesion of a new coat of paint.

Plus, if the solder flowed through on the (presumably copper?) wire to both sides of the hole, it would form a fairly snug "plug", holding pretty well mechanically. Signal-strength problems may arise later, though, when corrosion works in between the solder and the aluminum.

If the material will stand the gaff, pop-rivets might be a longer-term solution. (Then again, the rivets might simply rip through the thin can walls before "popping" properly.)
SharpyWarpy3 years ago
Here's an idea that make your connections to the cans better. As Dr. dB has said soldering is iffy because all it's doing is building up on the copper wire forming a "plug" because it can't adhere to aluminum. So why not drill a hole in each can the size of a small nut and screw combination. Tin the ends of your copper wires. Form loops the size of the diameter of your screws. Secure the rounded tin copper wire leads under the head of the screw with the wire arranged in a clockwise direction -- which will ensure the lead doesn't back out and off the screw while it is being tightened. A good sanding on the can around the screw holes will permit a solid connection. To prevent future corrosion problems apply hot glue to the finished connections.
Free until DTV takes over??? do you even know what you are talking about at all lilshawn... not trying to be mean or anything but frankly you don't have a clue and you shouldn't knock something till you have at the very least tried it!! I built this antenna as described, but my can of choice was a coke can lol, and on my DIGITAL receiver with a couple of small positional tweaks to find the sweet spot i now receive all 25 local digital channels with no problems at all :D and i havent gone all fancy like you did soldering it together :P I simply bared 4cm of wire on the connecting ends, poked a couple of small holes in the base sections of each half of the can and looped it through and twisted it tight (It's worth noting that all cans for health and safety reasons have a thin protective coating that is non conductive and a light scratching or sanding should be applied to the area of connection to ensure maximum conductivity). Now im just mad at myself for spending $30 on an antenna with built in signal amplifier that struggled to find 18 channels...
will this help me with analog channels?
bobby5614 years ago
were do i get a red\black wire
Maplin (UK) Radioshack (US) Garden centre Hardware store It doesn't need to be red and black however, two bits of wire will do.
pyrojunky5 years ago
this may all be true about police and emergency services needing more analog space, that is fine. my beef is if the government is doing this then they should also insist that cable and satellite providers provide everyone with "free" local broadcast channels at no cost. as it sits presently i have been thru 4 converter boxes 5 different types of antennas (including the ones i was previously using with no problems) and i still can not get even half of the channels i did prior to the switch. this is why i am now looking for alternate forms of antennas on here. i don't feel its right for me to have to pay for something that i was getting and should still be getting for free. i don't watch much tv as it is and did not benefit from cable that is why i did not and do not have it
I know this is a reply to an old post, but may be useful... alot of cable companies offer what is often called "antenna Service." You usually have to haruange them a bit to even admit it exists because they want to sell you something, but you can usually get it. Also, it's not uncommon for the antenna service just to be there if you hook the cable up to your telelvision. I don't know if this still applies in the age of digital tv, but it used to. just some food for thought

I don't think TV is a right - but I hear your frustration. I think the reception is up to the individual, so it's your responsibility.
Also, some areas have old laws w/ cable that requires basic local channels w/ basic service. Around us it costs about $15 a month for local + about 100 channels of infomercials ;-)
I'm happy with the HDTV over the air so far - some adjustments, but it's kind of fun. I don't have cable. Would rather not pay for TV. What I get free is enough of a time waster, along w/ the net...
"thebriguy"........................good response........well put
xtoddx5 years ago
So my coaxial cable only has one wire. Then I noticed in your photo that the wires connect to the soda can seem to be altogether different wires, yes? Did you forget to include them in yr. materials list? What kind of wires did you use to connect the can to the coaxial cable?
spa31rky xtoddx4 years ago
Sorry if I sound a bit off here but.......................Co Ax has 2 wires.......Center than remove foil and you will see braided wire.......Hince........2 wires.........see it yet?
Coax has 2 'Wires' - one fat one in the middle and one flat one that looks like shielding around the outside.
Actually, the 2nd 'wire' is the fuzzy thin wire right next to what is the shielding.
ronmaggi xtoddx5 years ago
If it only has one wire than it is not coaxial. Perlaps you picked up some gto 15 wire. it looks like coax, but is just a 14 guage wire with LOTS of insulation used for SSB antennas.
Cameron6574 years ago
Erm, I don't think you researched this much. You'd have to be _extremely_ close to the television transmitter for this to work. If you want to make an antenna, you HAVE to make the measurements EXACT, not just cut a Coke can in half and solder coax to it. You also didn't consider putting a balun in between the antenna and coax, as the output of the antenna is 300ohm and the cable is 75ohm. Also, a simple dipole for UHF is very impractical. A yagi or stacked array would suit the situation more, or even just adding a reflector. I'm not trying to have a go at you, as this is a cleaver idea, I just think you need to research it a bit more.
Gjdj3 (author)  Cameron6574 years ago
In all honesty, I didn't spend too much time researching this. However, this provides a clear, reliable signal, and I believe that's all the experimental evidence I need to justify my project.
spa31rky Gjdj34 years ago
Very GOOD project. I was to believe that if a project gave results than that is what mattered. Your TV works and gets channels.........Project Success.........True? YES.........................................Very True.............................................enough said!
Sorry for double posting, but is your antenna picking up UHF or VHF? Because in a prime signal area, just about ANYTHING will pick up a VHF signal.
No doubt! Have you tested it with digital? Maybe if you check out the handy website at http://www.dxzone.com/xmj/ID/11183/ which is very useful for designing antennas. I'm sorry for sounding harsh, your project clearly works. It could just be that little bit better for even better results. Keep up the good work!
Cymbalta5 years ago
Down here on the LI - NYC border, I now receive an additional 21 stations. And a free education as 18 are Spanish, 1 Korean and one "Faith"
Spanish TV has the largest viewership in many of the states, so now we can be better prepared for our countries future merger. SSI is a done deal. 
the Watcher5 years ago
How did you solder to an aluminium can?
To solder to the can, take a utility knife and create a "crosshatch" area. A bunch of intersecting lines. Just don't cut through the can. Then you can solder here. You can use this same technique to solder directly to batteries. (Only in rare cases such as building a joule thief...)
Gjdj3 (author)  the Watcher5 years ago
I think there's an instructable somewhere on soldering to larger objects...

http://www.instructables.com/id/Soldering-to-large-metal-objects/
jasinth5 years ago
Would it be possible to get a close up picture between the Coaxial wire and the red/black connection?
lilshawn5 years ago
FIRST FAIL well...free t.v. until the DTV "takeover" in a few months. please note, i have cable and am not affected by the DTV "takeover" please also note that i use the word "takeover" because i feel there is no reason to change to DTV anyways.
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