How to make a fractal antenna for HDTV / DTV plus more on the cheap

Step 2 Drill holes and add mounting points

Drill small tap holes on the opposite side from the reflector in the following positions and place a conductive screw.

Comments

[jschwab]

I've modified the design to increase fractals, adding another set of fractal "whiskers" giving 3 sets per side and iterating the fractal shape several more times, while still fitting into the same compact space.

bending the wires is a little time consuming, but in theory it should add more stable reception. i thought it might be helpful if anyone else was curious about increasing the fractal bends.

Attached here is a pdf for use as a guide / template.

Also, this can easily be mounted to cardboard, pexiglass etc and placed INSIDE the project box, to conceal the antenna.

[festizio]

At what size should I print this template to achieve the same center channel as the one from the main instructable?

[jschwab]

I printed mine at the default printer setting for a full 8.5 x 11 page. hope this helps.

[festizio]

So, does the image take up the whole page?

[jschwab]

If you print with no scaling it should take up a little more than half the page. mine came out centered on the sheet of paper, with the longest edge measuring around 6 inches.

[festizio]

Thanks for the help, and thanks for an awesome Instrucable.

[blong1024]

Using this design, how would I attach the dipoles and transformer

[jschwab]

you would attache dippoles the same way as the original, at the apex or top of the fractal "star" pattern.

[jsilverman1]

I used your increased fractal design. I got very good reception from an 8x10" surface area. I did not get notably better reception than this design: http://uhfhdtvantenna.blogspot.com/

but the fractal design is smaller and safer (no pokey bits sticking out).

[Spokehedz]

Both designs are electrically the same. One design just happens to take up less space, which will let you cram more antenna into the same space--which makes them work better. More antenna == more gain == better reception

[dmoore19]

Not sure what is the true size of the fractals as my printer has scaling options. If I select no scaling of your .pdf file the the antenna footprint size appears to be about 6" X 8".

Thanks

[jschwab]

update: the original design gave me 56 channels.

with increased fractals (like the pdf above) i now get 88 scanned channels (southern california). that's a pretty significant improvement.

[jkunken]

I have used DIY homemade antennas within the last two years to receive HDTV with no complaints. Decided to try out this new antenna model for kicks and giggles. With the increased fractal resolution, along with a reflector, we were able to pick up channel 38.1 beaming from Santa Barbara, CA directly from San Diego, CA, over 170 miles away. Signal strength and quality were both > 50%.

With the reflector and this type of antenna, directionality is key. By shifting the antenna's azimuth by only 12 degrees East, we lost Santa Barbara and began picking up Mount Wilson's signals (pretty much all Los Angeles channels), also from San Diego (only 100 or so miles away); still damn good, however, reception is tightly locked, though also *very* stable. Sans reflector, there is an increase in the number of channels from adjacent broadcast antennas, with additional stability introduced from the fractal design.

Great job.

[garrison111]

Hi jkunken. Your input on the Fractal antenna caught my eye since I live in the San Diego area as well. If I may ask, on these channels your getting from Santa Barbara and LA area, is your antenna still the same size (perimeter) as the one shown being made here with just more fractrals? And is it mounted outside and elevated? You could be in a vary good spot for reception. Since I want to make one of these as well, I'm waiting with antisipation. Thank you. Garrison

[jkunken]

Hi garrison111,
we used the increased fractal design as a basis (same perimeter). We then mounted the antenna on the focal point of a Dish Network satellite dish, with the dish facing North, from San Diego. The dish sits on our balcony; second story, though we also have trees in the way. It has been several months since the system was put in place and we still receive 50+ channels, mostly from Los Angeles, though we also receive adjacent channels from San Diego.

[garrison111]

Thank you for replying jkunken. I'm sorry I didn't get back sooner. My Mother is recovering from surgery. Using the focal point of the Dish Network sat dish was brilliant! Because of the dish being a parabolic shape, it means everything being reflected is hitting the antenna. Great Idea! I have several questions if I may ask. Where would I look to get get a used sat dish? Is the antenna still mounted in a vertical (up-right) position or is it turned 90 degrees on it's side as shown in one of these photos that someone did? Are you able to get any lower band channels, say 2 ~~ 13?
I few years ago, I bought and put up the most powerfull antenna that Wineguard makes. I live a little way down from the top of a hill in National City. The antenna, 9 feet by 14 feet was raised 48 feet from the ground. I was able to get a lot of channels out of LA as well but they were unstable coming in out all the time. The wind from a storm in Dec of 09 blew my telescoping pole system in half. And that was the end of that. But you managed to do the same thing with far less. Are your LA channels and beyond stable? Thanks for your input jkunkin and waiting your reply. garrison 111

[jkunken]

Garrison111,
yes, the satellite dish increased the gain quite a bit. The antenna is mounted vertically, not on its side, and in fact, most of the stable LA channels the antenna receives are in the VHF range (2 - 13), in addition to a variety of foreign language channels in the UHF range, of course. This is remarkable since DTV reception is based on the UHF range, afaik. One of the keys to stability is minimizing the use of splitters, since the signal can drop by several dB, as well as keeping coax cable lengths to a minimum; the longer the cable the greater the reduction in stability, say, if the cable is moved around. I believe tripods and satellite dishes can be purchased for around $100 from companies selling OTA receivers.
Good luck with your project.

[garrison111]

I was wondering jkunken. You mentioned you used the increased fractal design. I assume you mean with the extra iterations. The first design showen here by Ruckman has two sets of wiskers. There's another called increased fractal pdf using three sets of wiskers. Is that the one you used? It looks as though measured in a stright line from one end of the wire to the other end would be 3 inches long with the iterations along the way. But the print outs show them being smaller. Were yours 3 inches also with the extra iterations added?
It's great that this antenna can pick up both UHF and VHF bands. On the loss of db, if an amplifier is placed close to the antenna, that should compinsate for line loss.
On the dish search, I jsut remembered. I believe and have seen them being sold on craigs list pretty cheap.
Thanks again and waiting your reply. ~~ garrison111

[feltonite]

 Pardon my ignorance, but what materials do you use for the reflector?

[williamruckman]

It was an aluminum plate. Aluminum foil or aluminum/copper mesh can work as well.

[howoigbe]

I really want to design this antenna but I dont have copper, what of If I cut aluminium plate to the shape will it work? and Does size really matters? What it work indoor?? Africa

[williamruckman]

aluminum will work just fine. any conductive material will work. it will work indoors but not as well but that is the same with any antenna. size does matter, it can change the dynamics of the antenna. you can go to my website where i have links to a dipole calculator that will help you make the right size.

[howoigbe]

I need ur support on free energy like this http://www.youtube.com/watch?v=YNHOtzgTok8 . I want to construct one. Thanks

[howoigbe]

1.Note: I want to use Aluminum Sheet to cut the shape not cable type, will it still work??? 2. Give me dipole calculator url??

[williamruckman]

Yes, it will work. Here is the URL:

http://www.kwarc.org/ant-calc.html

[Om_Audio]

link is broken- I am looking to make one for my Sansui TU-717 FM Tuner- thanks! (http://www.flickr.com/photos/48136705@N05/4607622985/)

[howoigbe]

1. Can Omni Antenna be used for TV?? 2. Do U have free energy tutorial. e.g magnet???

[curiousgeorge03]

William,

Thanks for the instructable!  It is really cool.  I came across your design the other day and decided to try it out this past weekend and it worked pretty good, just in my living room and with no reflector.  My antenna is made with 8 dipoles instead of 4.  I sort of combined your design with the bowtie design.  I was able to pick up all the same channels as my two uhf only antennas from Radio Shack.  Granted I had to rotate the antenna to aim it in the right direction and not all signals came in as strong.

The antenna is not totally finished.  It's still missing a reflector.  I've read on some other sites that wire mesh might work better as a reflector, as opposed to a sheet of aluminum.  What do you think?  Also, is the distance between the dipoles and the reflector important?  My dipoles are on mounted on 1/2" plywood stick.  If I put the reflector on the opposite of the plywood, would it be too close?

I am going to try to add this antenna with my existing two in the attic and combine all the signals into one to see if it will improve my reception.  I plan to point all three in slightly different directions to be able to pick up all the stations.  I don't have a rotator.

Thanks again for the cool design.

[erik61820]

i cobbled together a couple of these antennas tonite, I was able to get a chan they couldnt before with amplified rabbit ears, and I needed one. I can also get the same chan that I couldnt before with regular rabbit ears that had 5 foot whips.

They both work really well, One has a balun one doesnt..They both are superior to
the amplified & unamplified rabbit ears. The next time I make another I will probably solder things together and better the construction.

Thanks for the plans

[Buskieboy]

Is this the plastic cover?  I am assuming the reflector is right up against the plastic cover?  Wouldn't the screws make contact with the reflector underneath?
Sorry for being such a noob, but I want to really make this and need some clarification on this part of the assembly.

[williamruckman]

This is the top of the box. The reflector and lid screw on the bottom and they are far enough apart that the reflector isn't contacted by the screws. In this case, the reflector fits into the bottom lid. It is internal.

[Buskieboy]

Ah, so you use the whole box as well!  It seems perfect for this project.
I see now, thank-you.