Cband Dish Modified for WiFi

[Pixl]

Originally posted in another thread, I had a few requests to put up some more pictures and details about this project.

I had put together an old Wilson 9ft. solid steel dish, but it never worked well for Cband FTA. I decided to re-purpose the dish to receive a distant WiFi signal from a resort that is across the lake. I constructed a "can-tenna" as the feed horn using a 3" copper pipe and end cap.


I found the formula for can-tenna dimensions on the net, mounted a N connector and soldered 1.25" brass probe inside.


I used a Asus router and loaded it with DD-WRT firmware which allows a bridge client mode that reverses the router to become a receiver. Most any brand router that uses Linux operating system will work, and some already have a bridge client mode feature in them. I put the router in a waterproof case and mounted it on the back side of the dish.


Either-net only uses 4 wires of the cat 5 cable, so DC power can be sent down the other 4 wires doubled up, the wall wart is then kept in the house at the other end.


The dish works just fine for WiFi signals, here it is serving up free internet from an open AP.

 

[SatelliteAV]

Great project and description!

Does feedhorn placement or a scalar have any effect on the signal?

 

[FaT Air]

Excellent re-utilization. Distance to the AP? Do you plan on trying different feed types for comparison? (Biquad, PC Board - Log Periodic - yagi, helical)

 

[Pixl]

Great project and description!

Does feedhorn placement or a scalar have any effect on the signal?

Sliding the feed in and out does not change it very much the way C or Ku does. I left it set at the same focal point the C feed was at. I did not try a scalar on it. I presume it would have to be designed for 2.4 ghz and I have no idea about that.

Excellent re-utilization. Distance to the AP? Do you plan on trying different feed types for comparison? (Biquad, PC Board - Log Periodic - yagi, helical)

The AP is about 3/4 mile from the dish. The only comparison was to the black plastic antenna that came with the router and was a tremendous improvement over that. It would be fun to try other antennas as you suggest, but the dish is quite a drive from my home, not to easy to experiment with.

 

[xtgold]

nice copper
the best I ever achieved was 2 miles with a wok cover reflector and 500mw usb wifi device

 

[SatelliteAV]

Did you try adjusting the skew? I found that my cantenna reception can be greatly influenced by changing the polarity angle.

 

[Pixl]

Did you try adjusting the skew? I found that my cantenna reception can be greatly influenced by changing the polarity angle.

I should try that, I just presumed vert polarity.
Did you build your cantenna? What did you use for it?

 

[wallyhts]

Very nice. Any problems sending traffic back? Have u ever played with net stumbler?

 

[Bob2011]

I like that color you painted the dish

If there was a similar dish on the other end you could share the internet at five or maybe ten miles

 

[Anole]

been there, done that, got the T shirt

Adjusting skew is good idea.
Match the polarity of the other end.

Helical antennas are either right hand circularly polarized or left hand.
Best gain is when same Polarity used at each end.
Circular on one end, linear on the other, creates loss,
but might be beneficial to a moving vehicle.
...or maybe if there are a lot of moving reflectors between stations.

Raising power on only one end isn't recommended.
Does nothing for your receive signal.
Jacking the power on routers is both illegal, and can lead to early burnout.

 

[Blindowl1234]

I've been thinking of trying something like this too. My problem is way too many trees in the direction of any wi-fi signal that I might get. I'm still thinking of trying it though. I'm figuring my closest signal might be a mile way though.

 

[SatelliteAV]

I built my cantenna out of a pineapple juice can. Hole punched for a SMA panel jack with soldered antenna stub. Have a threaded screw centered in the rear of the can and attached to 1/2" conduit mast that mounts in a flag post holder. This screw attachment allows the can to skew while mounted the mast.

Not as fancy as the beautiful copper work of art that you designed, but it does a great job in the campgrounds. Provides 70% or more bars when the laptop internal WiFi doesn't even have a sniff of a signal.

Also built a modified cantenna with a tuna can and mounted in place of the LNBF on a 90cm. Incredible gain! Would love to try DXing with a BUD! I think the 802.11 record is 237 miles by a group in Venezuela.
http://www.engadget.com/2007/06/19/venezuelans-set-new-wifi-distance-record-237-miles/

 

[Anole]

I'm figuring my closest signal might be a mile way though.

I would make a small antennna, then start close to the wifi source.
Work your way back through the trees, and see how you do.
Any chance you could trim some on the way?

 

[Stargazer]

I have seen a webpage where they used a Primestar dish with a homemade biquad feed for wifi a while back. You are better off getting your gain with your antenna vs getting it with amplification. Amplification increases noise.

This setup is like a small pringles can setup attached to a dish. I have seen Ubiquiti type of radioes attached to satellite dishes serving as the feedhorn.

I am also curious how the different types of antenna's in front of a C-Band dish will work.

 

[turbosat]

Great innovation, though I don't understand much of the concept. Are these setups just grabbing internet access from somebody's unsecured wifi ? Is that legal? Or is the wifi on the other end aware and purposely left "open" for the experiment? It IS curious though, and I fear if I messed with it, then I would have another hobby to become hooked on. I still find it totally amazing to get tv signals from a flying space object in near-earth orbit.

 

[Blindowl1234]

Turbo I don't advocate stealing someone else's wi-fi but there's some public wi-fi spots and restaurants, campgrounds etc..some public libraries. Shoot I've seen people in their cars with laptops at the local library hours before they opened lol

 

[Blindowl1234]

I would make a small antennna, then start close to the wifi source.
Work your way back through the trees, and see how you do.
Any chance you could trim some on the way?

No way of clearing the trees here. I might get bored this summer and see what I can get to work.