Free antenna experiment...any takers?

Free antenna experiment...any takers?

Summary: I'm buried in meetings today, so more posts will be coming later, but I just wanted to post a quick link for people looking to blast WiFi cheaply through those fortress-like walls of public schools.Freeantennas.


I'm buried in meetings today, so more posts will be coming later, but I just wanted to post a quick link for people looking to blast WiFi cheaply through those fortress-like walls of public schools. offers DIY methods for boosting WiFi signal and the following video offers a few more details

Have your students give this a shot and report back. How does it work? I'll happily post any student reports. Happy hacking!

Topics: Mobility, Networking, Wi-Fi

Christopher Dawson

About Christopher Dawson

Chris Dawson is a freelance writer, consultant, and policy advocate with 20 years of experience in education, technology, and the intersection of the two.

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  • This is old...

    I found an article on this about 3 years ago in either Science Digest or Discover Magazine. I didn't need to try it because my wireless router is only about 20 feet my my living room PC, so I can't offer up any proof as to how well it works.
  • RE: Free antenna experiment?any takers?

    Pringles cans have been used for years as well... Or
    there is the "cantenna." Take an old soup can and
    turn that into an improved antenna. About as old as
    consumer wifi...
    • Like I said

      This was a quick between meetings post...however, that old consumer wifi is in a lot of our schools and worthy of experimentation :)
  • RE: Free antenna experiment???any takers?

    I used this very same template 3 or 4 years ago. Worked very well.

    none none
  • LOL - break the law experiment?

    Not that I think you or any kids are likely to get caught but...

    Try teaching kids the legal way before teaching them how to break the rules.

    You do realize that technically boosting signals will violate FCC regulations and laws limiting the power of unlicensed signals in this frequency range? And there are some reason for that like interfering with the rights of neighbors to use spectrum. Because "hotrod" rigs will generally end up broadcasting more power than needed in some directions. That is why the FCC requires engineering qualifications to legally change your power and antenna output.

    The legal way to fix the problem is to drill holes through walls and wire your wireless nodes outside the wall in rain-proof boxes. The same for inside walls. Use that wired backbone and add nodes to cover as needed.

    Although I am guessing your blasting experiment is probably to get around the need to put in expensive optical isolators or fiber optic networking. That being needed to keep lightning from running from one outside node through the entire wired backbone. Still USED 100Mbps optical gear is pretty cheap especially the single 100Mbps wire to optical convertor adaptors.

    This refers to the limits that FCC licensed radio engineers can use;Item=9

    Unfortunately even if you happen to comply with the broadcast power limits (by accident if you have not studied the subject) -- you are still technically in violation of FCC rules that require that such modifications be made by licensed (therefore qualified) persons.

    You know the same sort of government shortsightedness that doesn't let ordinary people work on commercial jet engines when it would be so much cheaper to use such people and an Internet HOW-TO guide. Yeah while safety is certainly not normally as critical (except maybe for people with pacemakers) the darn FCC still thinks the subject complex enough to require qualified people to make mods.
    • Next? Street racing, Zipguns & Explosives?

      My point is that just because you find it on the Internet does NOT make it legal. Nor does the number of people doing it.

      But if you are going to break laws this is probably the preferred type of law breaking. Exactly equivalent to removing mufflers from cars.

      At most you annoy neighbors and get a legal hand slap. Boosting power is usually treated as the equivalent of parking meter violations if your annoyed neighbors even know to call the FCC...although the FCC can impose much more serious penalties if they choose.
    • Postal Sales does not certify idea legal

      LOL - I can remember how long Canada sold VHS copy protection cracking devices and satellite decoders.
    • You're not breaking any laws here

      Not with the Al-foil antenna, anyway. If you read the two pages you link to, you will see that PTP (anisotropic - non-circular, or directional) broadcast has different limits than isotropic broadcast. From the first link [wifihowto...], with a 200 mW transmitter (supposedly 2X the power in a typical home router, according to the 2nd link [wi-fiplanet...]), you are allowed up to 27 dBm antenna gain, and with a 2 dB antenna + 10 dB Al-foil boost, that is ... [b]12 dB[/b]. (My 5th grader tells me that 12 < 27.) Even with an isotropic antenna on a 100 mW transmitter, you can use up to a 15 dB gain antenna.

      So, before you spout off about something, how about working the numbers first (as your sig goes, "well, Duh!).
      • Dude, lighten up!

        He didn't say EVERY fix would break the law!
  • How about the other end?

    Would the focusing power of the foil help a receiving antenna pull the signal in better (for a desktop across the house with a USB-attached external antenna)?