Spotted in the MAKE Flickr Pool, this homemade fractal antenna for digital television signals by Roy Jacobsen of Fargo, ND. Instructions for, and discussions of, similar designs are available in this Instructable from William Ruckman. Judging from the comments over there, folks who have built their own fractal antennae are quite pleased with how they perform. But if you read this, Roy, we’d love to hear it straight from you. Drop us a comment or send me an e-mail and let me know how the antenna is working out for you.

Update: Roy writes…

When broadcast TV switched to digital, we tried a few different commercial antennas, but none of them pulled in all of the local stations. I even tried a $100 so-called “omni-directional” one up in our attic that was no better than the cheaper ones.

I then stumbled across a MAKE video that described a DTV antenna made from coat hangers and wire screwed to a piece of scrap plywood.

I figured I wasn’t out much if it didn’t work, so I made one, and by gum, it worked better than any of the commercial models. We still had to move it around to tune in all of the channels, and some days we had trouble with a couple of channels (the local Fox affiliate and PBS were the worst culprits). And it was ugly. But it worked.

I kept looking around for more DIY ideas, and found an instructable for a fractal DTV antenna. The fractal part of the design is that the elements were bent into a second iteration Koch curve (kind of like two-thirds of a Star of David).

Since this design had only four elements where my first attempt had eight, I thought I might do better by combining the two designs. I also decided to replace the coat-hanger elements with some copper wire I recovered from some scrap 12 gauge wire, and the plywood with some ½ inch thick clear acrylic. From that, my Fractal DTV Antenna – Version 1 was born.

That gave us a little stronger reception, a more compact design, and better-looking design. However, we still occasionally needed to move it around, turning it one way or another, or sometimes moving it closer to or farther from the TV.

So I kept thinking about what else I could try. First thought was to increase the length of some of the elements. Antenna 1 had sixteen-inch elements (eight inches per leg of each element). Antenna 2, the first fractal design, had eight inch elements (four inches per leg). So I thought I would try to a design that incorporated both eight and sixteen inch elements, with the sixteen inch elements using a third iteration Koch curve to reduce the area.

I also wanted to get away from the bolted-together assembly of antenna 2 and give the whole thing a stable base it could stand on. The elements are 18-gauge copper wire, and are soldered on to the 12-gauge vertical connecters. The base is a 5-inch square of ½ inch acrylic.

This one works the best; only minor direction adjustments are needed at times. Best of all, my wife actually likes how this one looks.

[Thanks, Roy!]

Sean Michael Ragan

Sean Michael Ragan

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and makezine.com. My work has also appeared in ReadyMade, c’t – Magazin für Computertechnik, and The Wall Street Journal.


  • http://rjacobse.wordpress.com Roy Jacobsen

    Happy to fill in some details! I’ve been noodling around with ideas for improving things ever since my second antenna attempt, and I’m happy with how this one turned out. (And judging by the inquiries from family and friends, I might have to go into production.)

    • Man

      I am new in DIY antenna. I built one antenna using William Ruckman’s design and it works. However some channels drop their signal and not so stable. I would like to try your design. Can you provide me with more specific design details or point me to a website. I am located in Iowa. Thank you.
      Man

    • http://www.facebook.com/spiralciric Aleksandar Ciric

      Could you please post somewhere some instruction details for this v2?

    • Rich

      I can’t judge the dimensions of your antenna without seeing the base. It would be logical that the 16″ elements are bent at 1/2″ increments, since there are 32 increments, and the 8″ are bent at 1″ increments. Is there any method to this, or is it the result of size and space considerations?
      Also, would there be an impact on signal reception with a heavier gauge such as 12-gauge for the elements and 8-gauge for the vertical connectors?

      Thanks, hope someone is still watching this!

      • Rich

        me again, just found the bigger pic on flickr so I can see the dimensions now. I still wonder if dimensions and element gauge affect recpetion. Thanks.

  • http://gravatar.com/williamruckman William Ruckman

    Nice design! That is exactly why I posted my initial design to instructables so that others could use the concept and create custom antennas at home for cheap and that is exactly what you did. The great thing is that they can be made for more than just TV as well. It just takes some calculations for the dipoles. I keep the original design on my main website at ruckman.net as well. Enjoy!

  • Varian

    Hi,
    How far away can you pick up with it? What kind of parts do you need to get and how much does each cost? What measurement for the coat hanger and how far a part do they need to be to pick up uhf channels 65 miles and 100 mile ? What do the measurement have to be to pick up the higher vhf channels and what do the measurement need to be to pick up the lower vhf channels 65 miles and 100 mile? Email me back with photos.

    Thanks,
    Varian

  • http://none Karen Swim

    I am researching this for some prison inmates–I need to know how many units (TV’s) can be hooked up to an antenna…or are they meant only for one? (They may need 100 of them, then!) Thank you for any advice you can offer–Here’s hoping you look at this once in a while.

  • Pingback: Things That May Disrupt the Digital TV Signal | Arts & Entertainment Articles()

  • Robert

    The transmission lines and matching transformer lines are horrible.

  • David Horner

    There is a problem people dont take into account. Its not the strength of the signal its the clarity. If you had ghosts on analog tv you will have ghosts or multiple signals on your digital signal. Where you could adjust the picture for best quality you cant with digital. You cant tell from a signal strength meter what the actual signal looks like. If it gets 2 signals slightly off from each other it will scramble them badly. I had to go with a very directional antenna and point it at the stations i wanted or a known good reflection to get a usable signal. An amp only made the weak reflections stronger to wipe out the one i wanted. My location has ghosts as strong as the originals on a plain antenna. I had to go with a very directional and a rotator as there are 8 differnt directions i need to aim to get the different stations. So now i just watch anime, shows and tv on the internet.